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With the goal of improving the mechanical properties of porous hierarchical carbon, cellulosic fiber fabric was incorporated into the resorcinol/formaldehyde (RF) precursor resins. The composites were carbonized in an inert atmosphere, and the carbonization process was monitored by TGA/MS. The mechanical properties, evaluated by nanoindentation, show an increase in the elastic modulus due to the reinforcing effect of the carbonized fiber fabric. It was found that the adsorption of the RF resin precursor onto the fabric stabilizes its porosity (micro and mesopores) during drying while incorporating macropores. The textural properties are evaluated by N2 adsorption isotherm, which shows a surface area (BET) of 558 m2g−1. The electrochemical properties of the porous carbon are evaluated by cyclic voltammetry (CV), chronocoulometry (CC), and electrochemical impedance spectroscopy (EIS). Specific capacitances (in 1 M H2SO4) of up to 182 Fg−1 (CV) and 160 Fg−1 (EIS) are measured. The potential-driven ion exchange was evaluated using Probe Bean Deflection techniques. It is observed that ions (protons) are expulsed upon oxidation in acid media by the oxidation of hydroquinone moieties present on the carbon surface. In neutral media, when the potential is varied from values negative to positive of the potential of zero charge, cation release, followed by anion insertion, is found.

Organic chemical reactions have been used to functionalize preformed conducting polymers (CPs). The extensive work performed on polyaniline (PANI), polypyrrole (PPy), and polythiophene (PT) is described together with the more limited work on other CPs. Two approaches have been taken for the functionalization: (i) direct reactions on the CP chains and (ii) reaction with substituted CPs bearing reactive groups (e.g., ester). Electrophilic aromatic substitution, SEAr, is directly made on the non-conductive (reduced form) of the CPs. In PANI and PPy, the N-H can be electrophilically substituted. The nitrogen nucleophile could produce nucleophilic substitutions (SN) on alkyl or acyl groups. Another direct reaction is the nucleophilic conjugate addition on the oxidized form of the polymer (PANI, PPy or PT). In the case of PT, the main functionalization method was indirect, and the linking of functional groups via attachment to reactive groups was already present in the monomer. The same is the case for most other conducting polymers, such as poly(fluorene). The target properties which are improved by the functionalization of the different polymers is also discussed.

We report the development of a hydrogel-based approach to select bull spermatozoa, a crucial step for successful assisted reproductive techniques (ARTs). Hyaluronic acid (HA) semi-interpenetrated N-isopropylacrylamide (PNIPAM) co-20% N-Tris (hydroxymethyl) methyl acrylamide (HMA) hydrogels were synthetized on glass surfaces and cultured in presence of frozen-thawed bull spermatozoa. A fraction of motile bull spermatozoa population strongly attached to hydrogels and was partially released by treatment with hyaluronidase. Fifty-nine (59 ± 7.24) per cent of sperm cells attached to PNIPAM-HMA-HA hydrogels and 31.16 ± 4.81% of them were released upon treatment with medium containing hyaluronidase. This attached-released sperm fraction has acceptable characteristics of progressive motility (50.0 ± 5.0%), vigour (4), high viability (58.7 ± 11.7%) and low percentage of acrosome reacted spermatozoa (23.36 ± 4.1%). Our findings indicate that PNIPAM-HMA-HA hydrogels are non-toxic and allow the selection of high-quality sperm cells for ART.

Hydrogels made of cross-linked polyacrlyamides (cPAM) and conducting materials made of polyanilines (PANIs) are both the most widely used materials in each category. This is due to their accessible monomers, easy synthesis and excellent properties. Therefore, the combination of these materials produces composites which show enhanced properties and also synergy between the cPAM properties (e.g., elasticity) and those of PANIs (e.g., conductivity). The most common way to produce the composites is to form the gel by radical polymerization (usually by redox initiators) then incorporate the PANIs into the network by oxidative polymerization of anilines. It is often claimed that the product is a semi-interpenetrated network (s-IPN) made of linear PANIs penetrating the cPAM network. However, there is evidence that the nanopores of the hydrogel become filled with PANIs nanoparticles, producing a composite. On the other hand, swelling the cPAM in true solutions of PANIs macromolecules renders s-IPN with different properties. Technological applications of the composites have been developed, such as photothermal (PTA)/electromechanical actuators, supercapacitors, movement/pressure sensors, etc. PTA devices rely on the absorption of electromagnetic radiation (light, microwaves, radiofrequency) by PANIs, which heats up the composite, triggering the phase transition of a thermosensitive cPAM. Therefore, the synergy of properties of both polymers is beneficial.

Graphene oxide (GO) and reduced graphene oxide have outstanding qualities that could be exploited as reinforcement and antibacterial agents in a plethora of biomedical applications. In this contribution, it is reported the deployment of a polyacrylamide GO-hydrogel composite (GO@pAAm) which was photo-converted and structured by ultra-short laser irradiation using a direct laser writing (DLW) approach. The materials were characterized by Fourier Transform Infrared spectroscopy, scanning electron microscopy and confocal microscopy. The laser structure generates a multi-photo-induced effect: surface foaming and patterning, microdomains with enhanced selective water-swelling and effective GO photo-reduction. A first laser scan seems likely to induce the photo-reduction of GO and subsequent laser pulses trigger the structure/foaming. The photo-reduction of GO is evidenced by Raman spectroscopy by the relatively changing intensities of the D to G signals. Macroscopically by an increase in conductivity (decrease in sheet resistance from R S-GO@pAAm = 304 ± 20 kΩ sq−1 to R S-rGO@pAAm-DLW = 27 ± 8 kΩ sq−1) suggesting a reduction of the material measured by 4-Point-Probe.

The mechanochemical synthesis of polyanilines (PANIs), made by oxidative polymerization of anilines, is reviewed. First, previous knowledge of the polymerization reaction in solution is discussed to understand the effect of different parameters: oxidant/monomer ratio, added acid, oxidant, temperature and water content on the properties of the conducting polymers (molecular weight, degradation, doping/oxidation level, conductivity, and nanostructure). The work on mechanochemical polymerization (MCP) of anilines is analyzed in view of previous data in solution, and published data are critically reconsidered to clarify the interpretation of experimental results. A key factor is the production of acids during polymerization, which is often overlooked. The production of gaseous HCl during MCP of aniline hydrochloride is experimentally observed. Since some experiments involves the addition of small amounts of water, the kinetics and heat balance of the reaction with concentrated solutions were simulated. A simple experiment shows fast (

The commercial development of high-energy lithium–sulfur (Li–S) batteries is still hampered by the irreversible active material loss and fast capacity decay triggered by the dissolution of polysulf...

Some of the essential properties for cellular scaffolding are the capability to maintain the three-dimensional (3D) structure, good adhesion, and adequate elastic modulus during cell growth, migration, and proliferation. Biocompatible synthetic hydrogels are commonly used as cellular scaffolds because they can mimic the natural extracellular matrices (ECMs). However, it is possible that the physicochemical and mechanical behavior of the scaffold changes during cell proliferation and loses the scaffold properties but this is rarely monitored. In this work, the physicochemical and mechanical properties of a macroporous soft material based on poly(N-isopropyl acrylamide) (PNIPAM) have been studied during a period of 75 days at culture condition while bovine fetal fibroblasts (BFF) were grown within the matrix. The interconnected macroporous hydrogel was obtained by cryogelation at -18 °C. The swelling capacity of the scaffold was not altered during cell proliferation but changes in the mechanical properties were observed, beginning with the high elastic modulus (280 kPa) that progressively decreased until mechanical stability (40 kPa) was achieved after 20 culture days. It was observed that the matrix-cell interactions together with collagen production favor normal cellular processes such as cell morphology, adhesion, migration, and proliferation. Therefore, the observed behavior of macroporous PNIPAM as a 3D scaffold during cell growth indicates that the soft matrix is cytocompatible for a long time and preserves the suitable properties that can be applied in tissue engineering and regenerative medicine. Fil: Rivero, Rebeca Edith. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Capella, Virginia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Biotecnología Ambiental y Salud - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Biotecnología Ambiental y Salud; Argentina Fil: Liaudat, Ana Cecilia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Biotecnología Ambiental y Salud - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Biotecnología Ambiental y Salud; Argentina Fil: Bosch, Pablo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Biotecnología Ambiental y Salud - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Biotecnología Ambiental y Salud; Argentina Fil: Barbero, César Alfredo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Biotecnología Ambiental y Salud - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Biotecnología Ambiental y Salud; Argentina Fil: Rodriguez, Nancy. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Biotecnología Ambiental y Salud - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Biotecnología Ambiental y Salud; Argentina Fil: Rivarola, Claudia Rosana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina

Heterogeneous acid catalysts were prepared by sulfonation of nanoporous carbons (NPCs). The NPCs were produced by pyrolysis of resorcinol-formaldehyde nanoporous resins (NPRs). The NPRs were synthesized as wet gels by condensation of resorcinol and formaldehyde in a sol-gel polycondensation using Na2CO3 as catalyst. A cationic polyelectrolyte (poly(diallyl dimethyl ammonium chloride)) was used as pore stabilizer, allowing to dry the gels in air without any special procedures. Five NPRs with different properties were synthesized by varying the monomer to catalyst ratio (Resorcinol/Na2CO3, R/C). The morphological and textural characterizations of the NPCs were performed by scanning electron microscopy and nitrogen adsorption-desorption isotherms. The results indicate that using a molar ratio of R/C=200, a nanoporous carbon NPC with large surface area (695m2/g) is obtained. This NPC was sulfonated by reaction with three different sulfonating agents: (i) concentrated sulfuric acid; (ii) fuming sulfuric acid and (iii) chlorosulfonic acid in order to obtain a novel Fischer esterification catalyst. The amount of acid groups attached to the NPC surface was determined by titration using a modified Boehm method. The catalytic activity, for Fischer esterification reaction of different sulfonated NPCs, was compared with sulfonated NPRs, sulfonated commercial porous carbons and polymeric acid catalyst (cationic ion exchange resins, sulfonated fluoropolymers). The modification of NPCs with concentrated sulfuric acid seems to render the materials with more catalytic activity. The best sulfonated material NPC (PC200-H2SO4) shows a high catalytic activity for the esterification of acetic acid (90.8%) and oleic acid (60.6%) with ethanol. The conversion and conversion rate values are better than commercial acid catalysts. The results suggest that sulfonated NPC catalysts are promising materials for the synthesis of biodiesel and related reactions. Fil: Tamborini, Luciano Henri. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Militello, María Paula. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Balach, Juan Manuel. Leibniz Institute for Solid State and Materials Research; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Moyano, J. M.. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; Argentina Fil: Barbero, César Alfredo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Acevedo, Diego Fernando. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

A new family of PtFe catalysts supported on hierarchical porous carbon (HPC), with different porous sizes, was developed and tested as cathodes in oxygen reduction reaction in acetate-fed microbial fuel cells. The results obtained were compared with carbon black (CB), CB-PtFe supported catalysts. HPC400 was characterized by cyclic voltammetry, showing a good electrolyte accessibility in contrast to CB. The XPS analysis of HPC supports show a low content of oxygenated species on carbon surfaces. The morphological and structural properties of catalysts were characterized by SEM-EDX and XRD. The electrochemical performance was examined by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The CO stripping voltammetry was applied for the determination of the surface area of PtFe catalysts; these experiments were carried out in a three-electrode system. In oxygen reduction experiments by LSV, HPC400-PtFe and CB-PtFe show good current densities of − 10.3 mA cm−2 and − 9.09 mA cm−2, respectively. HPC300-PtFe presents the poorest performance (− 2.3 mA cm−2). The HPC500-PtFe is the catalyst with the major current density (− 26.19 mA cm−2). A similar behavior is obtained in microbial fuel cell (MFC) catalyst performances; the MFCs were evaluated during 16 days until biofilm formation and stabilization. An increment of the power density was observed with the number of days. The power density obtained for HPC500-PtFe was 3218.89 mW m−2, showing better performances compared with CB-PtFe (743.18 mW m−2), HPC400-PtFe (578.82 mW m−2), and HPC300-PtFe (266.82 mW m−2). Hierarchical porous structure in combination with large-sized macropores enhanced the catalytic activity of PtFe toward oxygen reduction reaction in microbial fuel cells.

Photothermal therapy (PTT) is a potentially curative treatment modality that in recent years has been the object of growing interest and rapid technological advances due to its specific therapeutic efficacy and because it is a non-invasive technique. Nowadays, several nanomaterials have been developed as photothermal agents including metallic and carbon-based nanoparticles, conducting polymers, and different kinds of nanocomposites, among others. In this article, the most relevant applications of these photothermal nano-agents in antibacterial and anticancer therapy are reviewed. Fil: Cuello, Emma Antonia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Bongiovanni Abel, Silvestre Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Barbero, César Alfredo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Yslas, Edith Inés. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Molina, María Alejandra. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina

OBJECTIVETo forecast the death toll of COVID-19 in the whole world by fitting the time series of reported deaths with a parametric equation (integrated Gaussian equation) related to Farr’s law.DATAThe time series of cumulative deaths due to COVID-19 produced by John Hopkins University and stored in a github repository.RESULTSThe projected total death toll will be 261680 (392520 – 183176) which represents the 0.003 % of world population. This number amounts to 0.054 deaths per 1000, while the mean in the world (all causes) is 7.7. The daily peak of deaths (7270 (+/-500)) happened the 15 (+/- 3) of April, meaning that we are in descending curve of the pandemic. The outbreak will end completely the 23th (+/-3) of June. However, already on 9th (+/- 3) of May, 2 σ (95.45%) of the deaths will have be occured. The projected death toll is much lower (5-10 times) than those forecasted by the Imperial College Group (ICG) even considering the best scenario of total suppression of virus transmission. Using actual mortality rates it is possible to back calculate which number of infected individuals would produce such mortality. The death toll arises from a number of infected individuals between 53 (worst case) and 3.3 million. The calculated number of infected individuals is significantly lower than that calculated by ICG (227.5 millions) with suppression.

A commercial biomedical Polyimide (PI) film was topographically and chemically modified by generating micrometric periodic arrays of lines using Direct Laser Interference Patterning (DLIP) in order to improve antifouling and antibacterial properties. DLIP patterning was performed with periods from 1 μm to 10 μm. The physical modification of the surface was characterized by SEM, AFM and contact angle measurements and, the chemical composition of the ablated surfaces was analyzed by ATR-IR and XPS spectroscopies. The antibacterial effects were evaluated through the effect on Pseudomonas aeruginosa colonies growth on the LB (Luria Bertani) broth. The results showed that the laser treatment change the topography and as a consequence the chemistry surface, also that the microstructured surfaces with periods below 2 μm, exhibited a significant bacterial (P. aeruginosa) adhesion decrease compared with non-structured surfaces or with surfaces with periods higher than 2 μm. The results suggest that periodic topography only confer antifouling properties and reduction of the biofilm formation when the microstructure presents periods ranging from 1 μm to 2 μm. On the other hand, the topography that confer strong antifouling superficial properties persists at long incubation times. In that way, polymer applications in the biosciences field can be improved by a surface topography modification using a simple, single-step laser-assisted ablation method. Fil: Cuello, Emma Antonia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Mulko, Lucinda Emma. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Barbero, César Alberto. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Acevedo, Diego Fernando. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Yslas, Edith Inés. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina

The generation of filaments constituted by nanocomposites allows printing pieces with functional properties. A method is proposed for incorporating nanoparticles in plastic filaments (thermoplastic polyurethane, PU) by diffusion in the swollen material. The nanoparticles must be dispersed in solvents (or solvent mixtures) in which the polymer swells but does not dissolve. Nanoparticles are incorporated mainly at the surface as revealed by SEM/EDS mapping. The thermal properties (studied by DSC and TGA) of the PU are only slightly affected by the presence of NPs. Test pieces successfully are printed using the modified filaments. Incorporation of solid lubricant (MoS2) nanoparticles decreases the coefficient of friction of the printed test samples.

PNIPAM hydrogels are widely studied materials which swell in a great extent in water and water like solvents (e.g. alcohols). The hydrophilic nature of PNIPAM networks is very attractive however it is an important disadvantage at the moment of encapsulating hydrophobic drugs, which minimize their use in other fields. In this work we studied the swelling in different solvent mixtures with water and also in pure nonaqueous solvents, some of them immiscible with water. Accordingly, PNIPAM gels swell strongly in highly polar solvents (e.g. chloroform) but it does not swell in slightly polar solvents (e.g.Toluene). The main interaction between the solvent and the polymer chain seems to involve the hydrogen bonding with the amide group, according to the calculated Hansen parameters (δh). It is possible to swell the gel in binary or ternary mixtures containing toluene. In that way, non-polar substances can be loaded inside the gel to change its properties. As a proof of concept, polyaniline (PANI) solubilized in chloroform using camphorsulfonate as solubilizing counterion. The obtained nanocomposites become sensitive to pH changing color and conductivity when exposed to basic or acidic aqueous solutions. Fil: Martinez, María Victoria. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Molina, María Alejandra. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Bongiovanni Abel, Silvestre Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Barbero, César Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina

A combinatorial library of hydrogels is produced by radical polymerization and tested for retention of iron (II) complexes, using a simple colorimetric high throughput screening (HTS). Six acrylamide monomers are used to produce a library of 21 cross-linked hydrogel matrixes. The swelling of all hydrogels is determined and related with the structure of each monomer unit present. The HTS shows that some materials are able to retain the tris(phenanthroline)iron(II) (Fe(Phen)32+) complex. The partition coefficient of Fe(H2O)62+ and Fe(Phen)32+ in all hydrogels is determined by UV–vis spectrophotometry and related with the presence of anionic (e.g. −SO3−), hydrophobic (e.g. isopropyl) and hydrophilic (e.g. −NH2 of acrylamide) groups. Hydrogels with sulfonic (−SO3−) groups show large values of partition coefficients of Fe2+ into the hydrogel (>500). Based on the data and HTS, poly(acrylamide-co-50%(2-acrylamido-2-methylpropansulfonic acid)) (PAAm-co-50%AMPS) is selected to build a colorimetric sensor. Since the phenanthroline could be released from the hydrogel, bathophenanthroline (BPhen) which is not released is used as ligand. The hydrogel is loaded with BPhen and exposed to Fe2+ in water. The visual detection of color gives a detection limit of 0.1 ppm. Little interference of different common ions is found. A special set-up is made which allows spectrophotometric measurement of the complex inside the gel. The detection limit is found to be of ca. 0.01 ppm by spectrophotometry. Using the sensor, the iron content in milk is measured directly demonstrating the use of the sensor to measure free iron in opaque liquids where solution spectrophotometry is not effective without complex sample pretreatments. The non-covalent retention of ligands and complexes inside polymeric hydrogels seems to be a suitable method for building specific ion sensors. Fil: Martínez, María Victoria. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Rivarola, Claudia Rosana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Miras, María Cristina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Barbero, César Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina

Polymeric nanocomposites were obtained by the formation of a thermosensitive hydrogel matrix around conducting polymer (CP) nanoparticles. The CP is able to absorb electromagnetic radiation which is converted into heat and induces the phase transition of the surrounding hydrogel. The method chosen to form the hydrogel is the free radical polymerization of a copolymer (N-isopropylacrylamide (NIPAM) and 2-acrylamide-2-methylpropano sulfonic acid (AMPS), PNIPAM-co-2% AMPS) in the presence of bisacrylamide as the crosslinker. The nanoparticles are polypyrrole nanospheres (PPy NP), polyaniline nanofibers (PANI NF), and polyaniline nanospheres (PANI NP). The morphology of the composites was studied using SEM microscopy and the percentage composition of each material was evaluated by thermogravimetric analysis (TGA). The swelling equilibrium capacity and rate are clearly affected by the nanoparticle shape and nature. However, the nanocomposites LCST are similar to that of the matrix. Upon RF irradiation, the three nanocomposites increase the temperature and reach the LCST after 320 seconds of irradiation (320 kJ). Upon MW application, the local temperature reaches the LCST after only 30 s (21 kJ), resulting in a MW more effective than RF to drive the transition. These results demonstrate that the proposed materials are useful as a remotely driven actuator. Fil: Bongiovanni Abel, Silvestre Manuel. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Rivarola, Claudia Rosana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Barbero, César Alberto. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Molina, María Alejandra. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina

A method for the synthesis of a linear block copolymer (PNIPAM-b-PANI), containing a thermoresponsive block (poly(N-isopropylacrylamide), PNIPAM) and a Near Infrared (NIR) light-absorbing block (polyaniline, PANI), is reported. The synthetic approach involves a two-step successive polymerization reaction. First, the radical polymerization of NIPAM is done using 4-aminothiophenol as a chain transfer agent for the obtention of thermosensitive block terminated with an aniline (ANI) moiety. Second, the oxidative polymerization of ANI is initiated in ANI moiety of thermosensitive block to grow the second conductive PANI block. 1H nuclear magnetic resonance (NMR) and FT-IR spectroscopy shows the characteristics peaks of both polymeric blocks revealing the successful copolymerization process. Static Light Scattering (SLS) and UV-Visible combined measurements allowed the determination of the Mw for PNIPAM-b-PANI macromolecule: 5.5 &times, 105 g mol&minus, 1. The resulting copolymer is soluble in water (8.3 g L&minus, 1) and in non-aqueous solvents, such as ethanol, formic acid, acetonitrile, and others. Both polymer blocks chains show the properties of the polymer chains. The block copolymer shows a lower critical solution temperature (LCST) at the same temperature (32&ndash, 34 &deg, C) than PNIPAM, while the copolymer shows pH dependent UV-vis-NIR absorption similar to PANI. The PNIPAM block suffers a coil to globule transition upon NIR light irradiation (785 nm, 100 mW), as shown by turbidimetry and Atomic Force Microscopy (AFM), due to local heating (more than 9 &deg, C in 12 min) induced by the NIR absorption at the PANI block. Furthermore, the electrical conductivity of PNIPAM-b-PANI thin films is demonstrated (resistivity of 5.3 &times, 10&minus, 4 &Omega, &minus, 1 cm&minus, 1), indicating that the PANI block is present in its conductive form.

Antimicrobial nanocomposites (NCs) are being used as an alternative antibacterial therapy for killing antibiotic-resistant pathogenic bacteria. The NCs are made of Ag nanoparticles (AgNPs) inside biocompatible hydrogel matrixes. The NCs were synthesized by the absorption of AgNO3 solution into a hydrogel matrix, followed by UV light irradiation, without using additional toxic reactants. The hydrogels used as matrixes are based on N-isopropylacrylamide (NIPAM) and copolymers with different functional groups: 2-acrylamide-2-methylpropanesulfonic acid (AMPS), N-hydroxyethylacrylamide (HEAA) and (3-acrylamidepropil)trimethylammonium chloride (APTMAC). Neutral, anionic and cationic groups were added to the matrixes in order to study their effects on the release of antibacterial species. The NCs were characterized by UV-visible spectroscopy and transmission electronic microscopy. The kinetics of the release of Ag+ ions from the NCs were followed by UV-visible spectroscopy at 300 nm. Biological experiments were based on the plate count method and agar diffusion testing against Pseudomonas aeruginosa. The bacterial death rate using the NCs is higher than when PNIPAM and nanoparticles in solution are used and seems to be related to the large amount of AgNPs contained inside the gels. In all cases, inhibition and diffusion halos were observed upon the exposure of bacterial cultures on agar to NC discs. The presence of both halos confirmed the bactericidal and bacteriostatic effects of the NCs. The reusability (prolonged use) of the materials was demonstrated until the Ag-NP content was exhausted. The NCs with a higher antibacterial capacity are based on a PNIPAM-co-6%APTMAC matrix. It was demonstrated that these NC materials have the capacity to maintain an aseptic/antiseptic zone for 7 to 15 days. Fil: Monerris, Melisa Jimena. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Broglia, Martin Federico. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Yslas, Edith Inés. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Barbero, César Alberto. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Rivarola, Claudia Rosana. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Several hydrogel surfaces present properties that simulate the mechanical andphysicochemical features of extracellular matrix (ECM), providing a platform that mimic the native cellular milieus. Poly-N-isopropylacrylamide (PNIPAM) hydrogels are receiving attention in biomedical field due to their thermosensibility and soft texture. However, more extensive biocompatibility and cellular interactions studies with cell lines are needed. Therefore, the aim of this study is focus on evaluating the biocompatibility of PNIPAM through cytotoxicity, genotoxicity, and proliferation tests in murine preadipose cells (3T3-L1), human embryonic kidney cells (HEK293) and human carcinoma-derived cells (A549) in presence of hydrogel surfaces. Bioadhesive capacity above PNIPAM surfaces was also analyzed. MTT and neutral red uptake assays shown non-cytotoxic effect of PNIPAM in the studied cell lines. Genotoxicity was evaluated by the single-cell gel electrophoresis assay, where DNA damages were not detected [3H]-thymidine staining allowed to corroborate that cell proliferation had progressed correctly. Adopted morphologies for each cell line over PNIPAM were similar to cell growing observed on polystyrene, indicating that the surfaces favor the cell attachment during 5 days´ culture. The good biocompatibility of PNIPAM surfaces make it an interesting scaffold withclinical potential in tissue regeneration engineering, and a possible adipose and kidney tissue-engineered construct. Fil: Capella, Virginia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Rivero, Rebeca Edith. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Liaudat, Ana Cecilia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Ibarra, Luis Exequiel. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Biotecnologia Ambiental y Salud. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Biotecnologia Ambiental y Salud.; Argentina Fil: Roma, Dardo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Clínica Animal; Argentina Fil: Alustiza, Fabrisio Eduardo. Instituto Nacional de Tecnología Agropecuaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Mañas, Fernando Javier. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Clínica Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Barbero, César Alfredo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Bosch, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina Fil: Rivarola, Claudia Rosana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Rodriguez, Nancy. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina

Biofilm Formation is a survival strategy for microorganisms to adapt to their environment. Microbial cells in biofilm become tolerant and resistant to antibiotics and immune responses, increasing the difficulties for the clinical treatment of microbial infections. The surface chemistry and the micro/nano-topography of solid interfaces play a major role in mediating microorganism activity and adhesion. The effect of the surface chemical composition and topography on the adhesion and viability of Pseudomonas aeruginosa was studied. Polymeric (polyethylene terephthalate) surfaces were covered with a conducting polymer (polyaniline, PANI) film by in-situ polymerization and microstructured by Direct Laser Interference Patterning (DLIP). The viability of Pseudomonas aeruginosa on the different surfaces was investigated. The physicochemical properties of the surfaces were characterized by water contact angle measurements, scanning electron microscopy and atomic force microscopy. Bacterial biofilms were imaged by atomic force and scanning electron microscopies. The bacterial viability decreased on PANI compared with the substrate (polyethylene terephthalate) and it decreased even more upon micro-structuring the PANI films. In addition, the biofilm reduction could be improved using polymers with different chemical composition and/or the same polymer with different topographies. Both methods presented diminish the bacterial attachment and biofilm formation. These findings present a high impact related to materials for biomedical engineer applications regarding medical devices, as prostheses or catheters. Fil: Gallarato, Lucas Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina Fil: Mulko, Lucinda Emma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Dardanelli, Marta Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina Fil: Barbero, César Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Acevedo, Diego Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Yslas, Edith Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina

Synthesis of antibacterial nanocomposite obtained by in-situ photoreduction of Ag+ ions impregnated inside a biocompatible hydrogel matrix is described. Hydrogel matrixes based on N-isopropylacrylamide (PNIPAM) and copolymers are synthesized by free radical polymerization in aqueous medium. The hydrogels are loaded with Ag+ ions and then silver nanoparticles (Ag-NPs) are obtained in-situ by application of UV light without using additives. Ag-NPs formation inside hydrogels is confirmed by UV-visible spectroscopy, scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM). An extensive characterization of nanocomposites is performed by determining the partition coefficient of Ag+ ions before photoreduction, the Ag-NPs mass loaded per gram of hydrogel as a function of irradiation time, swelling capacity and volume phase transition temperature. Fourier Transform Infrared (FTIR) spectra indicate the loss of some functional groups of the polymer backbone during reduction of Ag+ ions whereas13C NMR spectra do not show any change in the main carbon chain. Nanocomposites show antibacterial activity against Pseudomonas aeruginosas by release of Ag+ions while Ag-NPs remain inside matrix. Reducing/stabilizing character of hydrogel and antibacterial activity of nanocomposite depend on the chemical composition of the matrix. Fil: Monerris, Melisa Jimena. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Broglia, Martin Federico. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Yslas, Edith Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina Fil: Barbero, César Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Rivarola, Claudia Rosana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina

Resistive sensors for organic volatile compounds are built using functionalized polyanilines. The functionalization of polyaniline (PANI) is achieved by nucleophilic addition with thiols and is confirmed by X-ray Photoelectron Spectroscopy. The modified polymers tested as resistive sensors change the polymer sensitivity to volatile compounds. PANI shows a signal that increases when the chain length increases, however, functionalized polyanilines show a completely different behaviour. The sensitivity to long chain alcohols increases when PANI is modified with long alkyl chains, the opposite behaviour occurs when more hydrophilic groups are bonding to the polymer. We conclude that the different sensitivity of the functionalized polyanilines to the same volatile molecule allows identifying the analyte. In that way, multisensor arrays based on these materials could be used as an electronic nose. To explain this behaviour measurements of contact angle were performed. The data reveal that all modified polyanilines are more hydrophobic than PANI, this is likely to be due to the presence of the sulphur atoms. Therefore, we conclude that the hydrophobic/hydrophilic nature of the surface plays an important role but is not decisive in the sensor response. Also, Van der Waals interactions between the alkyl chains bound to de PANI and present in the sensed alcohols play an important role. Accordingly, the sensitivity for a plain alkane (heptane) increases strongly when PANI is modified with long alkyl chains. Fil: Cavallo, Pablo Césa. Universidad Nacional de Río Cuarto; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: Frontera, Evelina. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: Acevedo, Diego Fernando. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: Olejnik, Robert. Univerzita Tomase Bati Ve Zline; República Checa Fil: Slobodian, Petr. Univerzita Tomase Bati Ve Zline; República Checa Fil: Saha, Petr. Univerzita Tomase Bati Ve Zline; República Checa Fil: Barbero, César Alfredo. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina

Encapsulated systems of antioxidants control the bioavailability in foods, enhancing and conserving their quality. Biocompatible hydrogels based on poly-(N-isopropylacrylamide) (PNIPAM) and copolymers, crosslinked with N,N-methylenebisacrylamide (BIS), are proposed as scaffold materials of antioxidants. Hydrogels are synthesized by copolymerization of NIPAM and N-hydroxyethyl acrylamide (HEAA) or N-acryloyl-tris-(hydroxymethyl) aminomethane (NAT) co-monomers. In order to compare the behaviors of delivery systems, the same proportions of co-monomers are added. The studied phenolic compounds (PHc) are: 2-(2-hydroxyethyl) phenol (2-OH) and its isomer 4-(2-hydroxyethyl) phenol (4-OH) or tyrosol, and ferulic acid (FAc). By UV‐visible spectroscopy, the partition coefficients of antioxidants in matrix/aqueous medium are determined. To describe the behavior of each controlled release systems, new kinetic parameters are defined: initial concentration of loaded drug (ICLD), the maximum molar concentration of released drug from hydrogel (Ceq) and the elapsed time for releasing the 50% and 100% of loaded substrate, among others. Determined Pc values indicate that the intramolecular interactions between PHc and hydrogel increase with OH group amount inside matrix. The release kinetics of PHc from hydrogels are different depending on substrate-matrix intermolecular interactions. A long-time release could be favored by a more hydrophilic matrix such as PNIPAM-co-8%NAT, and quick release is expected by less hydrophilic matrixes as PNIPAM or PNIPAM-co-8%HEAA. Free and encapsulated PHc show antioxidant activity against photogenerated reactive oxygen species in aqueous solution.

With a notable advantage in terms of specific capacity (1166 mAh g−1), lithium disulfide (Li2S) has been considered a promising cathode material for high-energy-density lithium–sulfur (Li–S) batteries. In contrast to pure sulfur, Li2S opens the opportunity to implement alternative anodes such as silicon or graphite instead of hardly controllable lithium metal. However, its intrinsically low conductivity and the formation of soluble lithium polysulfide species during cell operation resulting in a poor cycling stability, especially in carbonate-based electrolytes. Herein, a reduced graphene oxide-wrapped Li2S particles (Li2S@rGO) electrode is presented for improving the electrochemical performance of Li–S batteries in carbonate-based electrolytes. A hydrothermally prepared rGO-covered MoS2 particles composite was fully lithiated and irreversible decomposed at 0.01 V vs. Li/Li+ to in situ produce a Li2S@rGO composite with a high Li2S loading of ≈5 mg cm−2. Despite operating Li–S cells in a conventional carbonate-based electrolyte, the resulting cathode exhibits high initial capacity (975 mAh gLi2S −1 and 1401 mAh gS −1 at 0.1 C), low degradation rate (0.18% per cycle after 200 cycles at 2 C) and excellent Coulombic efficiency (≈99.5%). This work provides a simple strategy to fabricate practical high-loading Li2S cathodes for high-performance Li–S batteries “free” of polysulfide shuttle phenomenon. Fil: Zensich, Maximiliano Andres. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Jaumann, Tony. Leibniz Institute for Solid State and Materials Research; Alemania Fil: Morales, Gustavo Marcelo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Giebeler, Lars. Leibniz Institute for Solid State and Materials Research; Alemania Fil: Barbero, César Alfredo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Balach, Juan Manuel. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina

Synthetic methods to obtain Ag-nanocomposites are widely studied in order to produce antimicrobialmaterials without using harmful agents for possible applications in biologic systems. In this way, thenanocomposites could be able to apply in biomedicine area avoiding going through exhaustiveprocesses of purification. Biocompatible hydrogel based on N-isopropylacrylamide (NIPAM)copolymerized with different proportions of methacrylic acid (MAA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPS), were proposed as matrixes of Ag-nanocomposites. A comprehensive studyof the physicochemical behavior, reducing and stabilizing character of the matrixes were carried out atpH 2 and 7. Hydrogel nanopores were used as photoreducing of Ag+ ions and stabilizing of Agnanoparticles(Ag-NPs) at the same time. Most of the matrixes showed high reducing character atpH 7 while at pH 2 it was significantly reduced. Photoreducer character at pH 7 increased with MAAco-monomer concentration and Ag-NPs sizes of 4?5 nm were obtained. In addition, it wasdemonstrated that acidic co-monomers favor the stabilization of Ag-NPs avoiding agglomerations. Itwas possible to conclude that the photoreduction reaction takes mainly place at pH 7 when nonbonding electron pairs from carboxylic and amide groups of the matrix are available. Therefore,biocompatible and antimicrobial nanocomposites can be easily synthesized without using damagingadditives(reducer, solvent) and be applied in biomedicine. Fil: Broglia, Martin Federico. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Balmaceda, Ivana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Carrizo, Florencia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Barbero, César Alfredo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Rivarola, Claudia Rosana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina

The Formic Acid Electro-oxidation (FAEO) on Pt/Au Nanoparticles (PtAu NP) supported on Hierarchical Porous Carbon (HPC), was studied by cyclic voltammetry and chronoamperometry. The supported HPC-Pt nanoparticles were surface modified by Au spontaneous deposits. The morphological and compositional characterization was performed by Scanning Electron Microscopy (SEM) coupled with Electron Dispersive Spectroscopy (EDS). A significant increase of the current densities for FAEO in the potential region 0.1?0.75 V RHE was observed on HPC-PtAu catalysts. The comparison with HPC-Pt electrodes results show that Au atoms presence on Pt nanoparticles is a key factor to improve the catalysts performance. Based on our results, a clear change in FAEO mechanism on HPC-PtAu catalysts with respect to HPC-Pt was evidenced. Fil: Cappellari, Paula Sofía. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Baena Moncada, Angélica María. Universidad Nacional de Ingenieria; Perú Fil: Coneo Rodríguez, Rusbel. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Moreno, Mario Sergio Jesus. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Barbero, César Alfredo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Planes, Gabriel Angel. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina

The presence of polyaniline (PANI) conducting polymer loaded in thick films of a transparent and thermosensitive poly(N-isopropylacrylamide) (PNIPAM) hydrogel network allowed for absorption of UV light and modification of dry (PANI@PNIPAM) nanocomposites by direct laser interference patterning (DLIP) at 355 nm. This resulted in a surface morphology of a nano-foam superimposed on a dominant line/groove pattern. The observations are rationalized based on currently accepted mechanisms for laser-induced polymer surface modification. Furthermore, the PANI in the nanocomposite films absorbs radiofrequency (RF) radiation remotely inducing the volume phase transition of PNIPAM. The swelled, low-roughness state for PANI@PNIPAM collapsed into a non-swelled and patterned film. The procedure provided the optimum RF dose range for preserving the surface topography of the films. The evidence suggests that the DLIP processing of PANI@PNIPAM films preserve the thermosensitivity of the original PNIPAM material and shows up the potential for tuning the surface morphology of the composite due to synergistic effects of both RF actuation on PANI and temperature rise of PNIPAM. In this sense, the surface pore size increase accompanying the development of line/groove pattern by DLIP, creates a structure onto PANI@PNIPAM films with potential for the development of remotely triggered soft-sensors and drug delivery systems.

The proposed method implies the electrochemical detection of an analyte preloaded in a hydrogel. In order to evaluate the potential application of this method, arsenic detection in tap water was performed. Polymeric hydrogels bearing cationic groups poly(Nisopropyacrylamide)-co-3-(acrylamidopropyl)trimethylammonium chloride were used to sorb arsenic ions, at basic pH, from thereal and synthetic stock samples. The concentration of arsenic was electrochemically determined using the loaded hydrogel and amodified glassy carbon electrode. Employing a cationic hydrogel, the peak current for the arsenic oxidation was ca. 8 times higherthan the peak current measured using poly(N-isopropyacrylamide), a neutral hydrogel, indicating a strong electrostatic interaction between the polymeric cationic groups and arsenite anions. By using this method, values of arsenic comparable to those measuredby Atomic Absorption Spectroscopy were obtained for tap water of small cities in Argentina. These results suggest that this new and easy method is suitable to sense a threshold limit of arsenic in real samples since the features of the hydrogel allow the arsenite loading into the matrix. Besides the cationic hydrogels could be employed to sampling on-field and to build a portable analysis system. Fil: Martinez, María Victoria. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Coneo Rodriguez, Rusbel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Bruno, Mariano Martín. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Acevedo, Diego Fernando. Universidad Nacional de Río Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Barbero, César Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina

The hydrophilic nature of hydrogels allows their swelling in aqueous solutions. In that way, any substance loaded inside the gel is exposed to the aqueous media and could be released if it is soluble in water. However, only substances that are soluble in water can be loaded inside a gel, which can be swelled only in water. In this work, we studied the swelling of poly(N-isopropylacrylamide) (PNIPAM) gels in nonaqueous solvents and their solutions with water. PNIPAM gels swell strongly in highly polar solvents, but they do not swell in slightly polar solvents (e.g., toluene). However, it is possible to swell the gel in mixtures containing toluene. The observed properties of PNIPAM gels allow describing them both as solvogels or amphigels. When the loaded substance is soluble in one solvent (e.g., water) and not in another (e.g., chloroform), the substance is not released but exposed to the new media. As a proof of concept, a colorimetric pH sensor active in CHCl3 and a Cu1+ sensor in water were built. Moreover, using a ternary solution containing toluene linear polystyrene can be loaded inside the gel, making a semi-interpenetrated network. Because PNIPAM swells in water and solvents immiscible in water, a liquid/liquid interphase can be set inside a gel. A near-infrared absorbing dye (soluble in CHCl3) is loaded in only half of a thermoresponsive PNIPAM gel. Upon near-infrared irradiation, only the region where the dye is loaded heats up driving the phase transition of PNIPAM. Fil: Martinez, María Victoria. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Molina, María Alejandra. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Barbero, César Alberto. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina

Alpha-amylase was immobilized inside three different polymeric matrices: polyacrylamide hydrogel (PAAm), polyacrylamide-graphene oxide nanocomposite (PAAm-GO) and alginate in order to study and compare the effect of the matrix on the catalytic performance. The morphology, swelling, mechanical properties, retention efficiency, and the catalytic behavior of these newly supported biocatalysts were studied. Nanocomposite made of PAAm-GO matrix incorporated 98% of the enzyme, likely through a cooperative effect, while alginate gels incorporated only 30%. Moreover, the enzyme retention using PAAm-GO reached a value of 97.5%. Starch hydrolysis catalyzed by the immobilized enzyme in PAAm-GO matrix showed similar kinetics profiles up to 5 cycles suggesting that the enzymatic activity is retained. These results compare very favorably with conventional immobilization in alginate where almost no activity was observed after 3 cycles. All results suggest that the PAAm matrices protect the biocatalyst allowing its reusability. Moreover, the improvements in enzyme catalytic properties via immobilization made this system as an excellent candidate in bio-industrial applications such as bioethanol production. Furthermore, the synthesized catalyst could produce a high yield of bioethanol by using enzymes and yeast immobilized in the same PAAm matrix. In this way, it is possible to produce sequential or simultaneous saccharification and fermentation.

Resistive sensors for organic vapors were made usingpolyaniline (PANI) and functionalized PANI as thin films ordeposits of PANI nanofibers. PANI thin films were synthesized byin situ chemical polymerization onto flat polyethylene films. PANInanofibers were produced by interfacial polymerization. Bothpolymeric materials were chemically modified through aromaticelectrophilic substitution or nucleophilic addition and used asactive materials in resistive sensors. The analysis of the resistancetimesensor profiles suggested that chemical modification affectsstrongly the sensor response. Moreover, the magnitude, the sign,and the rate of the sensor response showed differences for activematerials with the same chemical structure and differentmorphology. It is demonstrated that using only one conductingpolymer but creating material diversity by chemicalfunctionalization or morphological changes different sensorsresponses for the same volatiles can be obtained. This behaviorallows a simple way to produce sensors arrays which can be usedin electronic noses. Fil: Bongiovanni Abel, Silvestre Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Olejnik, Robert. Univerzita Tomase Bati Ve Zline; República Checa Fil: Rivarola, Claudia Rosana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Slobodian, Petr. Univerzita Tomase Bati Ve Zline; República Checa Fil: Saha, Petr. Univerzita Tomase Bati Ve Zline; República Checa Fil: Acevedo, Diego Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Barbero, César Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina

Increases in the prevalence of antibiotic resistant bacteria require new approaches for the treatment of infectious bacterial pathogens. A new therapeutic modality, which is called photothermal therapy (PTT) involves the absorption of Near Infrared Radiation (NIR) light by absorbing species (e.g. polyaniline nanoparticles) and transfer of the absorbed energy into the surrounding environment as heat that could cause pathogen death. Since the pathogen cells, and the surrounding tissue, does not absorb NIR radiation, an agent which strongly absorb the light has to be added. In this work, were performed experiments to determine if polyaniline nanoparticles (PANI-NP) in combination with NIR irradiation could be used to destroy Pseudomonas aeruginosa. Results reveal that this nanomaterial, following NIR exposure could be used for killing bacteria because it was observed a significant decrease in cell viability triggering cell death. In addition, the cell death mechanism was observed by DNA fragmentation. Fil: Bongiovanni Abel, Silvestre Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Gallarato, Lucas Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina Fil: Dardanelli, Marta Susana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Barbero, César Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Rivarola, Claudia Rosana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Yslas, Edith Inés. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina

The manuscript shows the application of unmodified graphene oxide (GO) as a photothermally susceptible material to trigger antibacterial effects. The synthesis and characterization of unmodified GO easily dispersed in aqueous solutions is also shown. High GO concentrations in the dark and low GO concentrations irradiated with near infrared light (NIR) produced death in nosocomial bacterium (Pseudomonas aeruginosa). It is demonstrated that GO dispersion in the dark produced a dose-dependent increase in the antibacterial action at concentrations up to 120 μg/mL. On the other hand, by using much lower concentrations (c.a. 2 μg/mL) of GO (non toxic in the dark) and irradiating with near-infrared radiation during 15 min, a degree of mortality of 98.49% was observed. The P. aeruginosa treated with GO and irradiated exhibited DNA fragmentation due to the physical damage of cell membranes. The GO 2 μg/mL dispersions proved favorable, since they do not induce cell death in the dark, whereas the combination with NIR light triggers the damage to the cell membranes. This characteristic is clearly an advantage in comparison with traditional antibacterial nanomaterials (such as nanoparticles), which induce cell killing due to the nanoparticles toxicity per se. Furthermore, this work provides a novel treatment for combating bacterial nosocomial infections without the use of antibiotics, opening a new area of clinical application via simple photothermal therapy., This work was supported by FONCYT (PICT-2716-2013, the SUMA2 Network Project, 7th Framework Program of the European Commission (IRSES ProjectNr. 318,903), enabling movability. C.A. Barbero D.F. Acevedo, E.I. Yslas are permanent research fellows of CONICET. J.Y. Pereyra thanks CONICET for graduate fellowships. The funding of FONCYT (PICT-2716-2013), CONICET, and SECYT-UNRC is gratefully acknowledged.

The performance of electrodes modified with electrochemically generated cobalt oxide nanoparticles for the oxidation of As(III) species was investigated by cyclic voltammetry (CV) and rotating disk voltammetry (RDV). The oxide nanoparticles were made by electrodeposition from cobalt oxides using CV without the reduction of water or anions. Controlling deposition parameters, different values of surface concentration (Γ) can be obtained. Electrochemical experiments (CV and RDV at different rotation rate) showed a shift in the As(III) oxidation potentials to lower values; when the coverage surface increased, these differences in the surface concentration produced a potential shift of up to 150 mV. This phenomenon depends on the ratio of the electrode active area to the geometric area (Ψ). The Levich and Koutecký-Levich analysis of RDV voltammetric data confirmed that the oxidation of As(III) on modified electrodes is controlled by mass transport. It was also demonstrated that different values of surface concentration produces different kinetic current values. Fil: Coneo Rodriguez, Rusbel. Comisión Nacional de Energia Atomica. Gerencia D/area de Seguridad Nuclear y Ambiente; Argentina Fil: Baena Moncada, Angélica María. Universidad Nacional de Ingeniería. Facultad de Ciencias; Perú Fil: Acevedo, Diego Fernando. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: Morales, Gustavo Marcelo. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: Planes, Gabriel Angel. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: Barbero, César Alfredo. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina

This work focuses on one of the most exciting application areas of conjugated conducting polymers, which is cell culture and tissue engineering. To improve the biocompatibility of conducting polymers we present an easy method that involves the modification of the polymer backbone using l-cysteine. In this publication, we show the synthesis of polyaniline (PANI) films supported onto Polyethylene terephthalate (PET) films, and modified using cysteine (PANI-Cys) in order to generate a biocompatible substrate for cell culture. The PANI-Cys films are characterized by Fourier Transform infrared and UV-visible spectroscopy. The changes in the hydrophilicity of the polymer films after and before the modification were tested using contact angle measurements. After modification the contact angle changes from 86° ± 1 to 90° ± 1, suggesting a more hydrophylic surface. The adhesion properties of LM2 and HaCaT cell lines on the surface of PANI-Cys films in comparison with tissue culture plastic (TCP) are studied. The PANI-Cys film shows better biocompatibility than PANI film for both cell lines. The cell morphologies on the TCP and PANI-Cys film were examined by florescence and Atomic Force Microscopy (AFM). Microscopic observations show normal cellular behavior when PANI-Cys is used as a substrate of both cell lines (HaCaT and LM2) as when they are cultured on TCP. The ability of these PANI-Cys films to support cell attachment and growth indicates their potential use as biocompatible surfaces and in tissue engineering. Fil: Yslas, Edith Inés. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina Fil: Cavallo, Pablo César. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Acevedo, Diego Fernando. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Barbero, César Alfredo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Rivarola, Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina

Polyaniline nanoparticles (PANI-NPs) were easily obtained applying the solvent displacement method by using N-methylpyrrolidone (NMP) as good solvent and water as poor solvent. Different polymers such as polyvinylpyrrolidone (PVP), chondroitin sulfate (ChS), polyvinyl alcohol (PVA), and polyacrylic acid (PAA) were used as stabilizers. Dynamic light scattering and scanning electron microscopy corroborated the size and morphology of the formed NPs. It was demonstrated that the size of nanoparticles could be controlled by setting the concentration of PANI in NMP, the NMP to water ratio, and the stabilizer's nature. The functionalization and fluorescence of NPs were checked by spectroscopic techniques. Since polyaniline show only weak intrinsic luminescence, fluorescent groups were linked to the polyaniline chains prior to the nanoparticle formation using a linker. Polyaniline chains were functionalized by nucleophilic addition of cysteamine trough the thiol group thereby incorporating pendant primary aliphatic amine groups to the polyaniline backbone. Then, dansyl chloride (DNS-Cl), which could act as an extrinsic chromophore, was conjugated to the amine pendant groups. Later, the functionalized polyaniline was used to produce nanoparticles by solvent displacement. The optical and functional properties of fluorescent nanoparticles (F-PANI-NPs) were determined. F-PANI-NPs in the conductive state (pH < 4) are able to absorb near infrared radiation (NIR) creating a photothermal effect in an aqueous medium. Thus, multifunctional nanoparticles are obtained. The application of NIR on a F-PANI-NPs dispersion in contact with Pseudomonas aeruginosa causes bacterial death. Therefore, the F-PANI-NPs could be tracked and applied to inhibit different diseases caused by pathogenic microorganisms and resistant to antibiotics as well as a new disinfection method to surgical materials.

Cationic, anionic and non-ionic hydrogels having acrylamide polymer backbones were synthesized via free radical polymerization with N,N-methylenebisacrylamide (BIS) as crosslinker. The chemical structures of the hydrogels were characterized by Fourier Transform Infrared Spectroscopy (FTIR). Physicochemical properties such as swelling kinetic, maximum swelling capacity, volume phase transition temperature (VPTT) and wettability (static water contact angle) of hydrogels swollen in aqueous and cell culture medium, at room and cell culture temperatures were studied. In order to correlate the surface properties of the hydrogels and cellular adhesivity of bovine fetal fibroblasts (BFFs), cellular behaviour was analyzed by inverted fluorescence optical microscopy and atomic force microscopy (AFM). MTT assay demonstrated that the number of viable cells in contact with hydrogels does not significantly change in comparison to a control surface. Flattened and spindle-shaped cells and cell spheroids were the adopted morphologies during first days of culture on different hydrogels. Cell spheroids were easily obtained during the first 5 days of culture in contact with PNIPAM-co-20%HMA (poly (N-isopropylacrylamide-co-20%N-acryloyl-tris-(hydroxymethyl)aminomethane)) hydrogel surface. After 15 days of culture all hydrogels showed high adhesion and visual proliferation. According to obtained results, non-ionic and hydrophilic surfaces with moderated wettability induce the formation of BFFs cell spheroids. These hydrogel surfaces could be used in clinical and biochemical treatments at laboratory level to cell growth and will allow generating the base for future biotechnologic platform. Fil: Rivero, Rebeca Edith. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Aluztiza, Fabricio. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina Fil: Capella, Virginia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Liaudat, Ana Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina Fil: Rodriguez, Nancy. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina Fil: Bosch, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina Fil: Barbero, César Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Rivarola, Claudia Rosana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina

The present work aimed to study the properties of a novel nanocomposite with promising biomedical applications. Nanocomposites were prepared by the addition of different concentrations of chitosan decorated carbon nanotubes to acrylamide-co-acrylic acid hydrogels. The nanocomposites chemical structure was characterized by Fourier Transform Infrared Spectroscopy (FT-IR). The FT-IR shows the typical bands due to the hydrogel and additionally the peaks at 1750 cm−1 and 1450 cm−1 that correspond to the carbon nanotubes incorporated into the polymer matrix. Mechanical properties and swelling measurements in different buffer solutions were also performed. The nanocomposites showed improved mechanical properties and a stronger pH-response. In order to evaluate antimicrobial activity, the growth and adhesion of Staphylococcus aureus to nanocomposites were studied. Cytocompatibility was also evaluated by MTT assay on MDCK and 3T3 cell lines. The nanocomposites were found to be cytocompatible and showed a reduced bacterial colonization. Fil: Bellingeri, Romina Valeria. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Anatomía Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Mulko, Lucinda Emma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Molina, María Alejandra. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Picco, Natalia Yanina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Anatomía Animal; Argentina Fil: Alustiza, Fabrisio Eduardo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Marcos Juárez; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Grosso, Maria Carolina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Anatomía Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Vivas, Adriana Beatriz. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Anatomía Animal; Argentina Fil: Acevedo, Diego Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; Argentina Fil: Barbero, César Alfredo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina

Pathological crystallization of calcium oxalate (CaOx) inside the urinary tract is called calculi or kidney stone (Urolithiasis). CaOx exhibits three crystalline types in nature: CaOx monohydrate COM, dihydrate COD and trihydrate COT. COD and COM are often found in urinary calculi, particularly COM. Langmuir monolayers, membrane vesicles, phospholipids’ micelles, among others, have been adopted as simplified biomimetic template-models to study in vitro the urolithiasis through CaOx. The nucleation and crystal growth of COM on self-assembled lipid monolayers have revealed that the negatively charged phosphatidylserine interface is a strong promoter of COM. Herein, we describe the synthesis and physicochemical characterization of diazotated sulphonated polystyrene films (DSPFs), prepared from various aminocompounds varying their polarity degree i.e., polar, non-polar and acidic DSPF derivatives. We also used these DSPFs as polymeric templates in crystallization experiments of CaOx in vitro. Images obtained by optical microscopy and scanning electron microscopy confirmed the precipitation of COM crystals on the DSPF surface. The employment of functionalized polymeric films as templates for CaOx crystallization represents a viable approach for understanding inorganic mineralization. Fil: Vásquez-Quitral, Patricio. Universidad de Chile; Chile Fil: Toledo Arana, Javier Marcelo. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Miras, Maria Cristina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina Fil: Acevedo, Diego Fernando. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Barbero, César Alfredo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Neira-Carrillo, Andrónico. Universidad de Chile; Chile

Photo-thermo-mechanochemical (P-T-MCh) nanocomposites provide a mechanical and/or chemical output (MCh) in response to a photonic (P) input, with the thermal (T) flux being the coupling factor. The nanocomposite combines a photon absorbing nanomaterial with a thermosensitive hydrogel matrix. Conjugated (absorbing in the near infrared (NIR, 750&ndash, 850 nm) wavelength range) polymer (polyaniline, PANI) nanostructures are dispersed in cross-linked thermosensitive (poly(N-isopropylacrylamide), PNIPAM) hydrogel matrices, giving the nanocomposite P-T-MCh properties. Since PANI is a conductive polymer, electromagnetic radiation (ER) such as radiofrequency (30 kHz) and microwaves (2.4 GHz) could also be used as an input. The alternating electromagnetic field creates eddy currents in the PANI, which produces heat through the Joule effect. A new kind of &ldquo, product&rdquo, nanocomposite is then produced, where ER drives the mechanochemical properties of the material through thermal coupling (electromagnetic radiation thermomechanochemical, ER-T-MCh). Both optical absorption and conductivity of PANI depend on its oxidation and protonation state. Therefore, the ER-T-MCh materials are able to react to the surroundings properties (pH, redox potential) becoming a smart (electromagnetic radiation thermomechanochemical) (sER-T-MCh material. The volume changes of the sER-T-MCh materials are reversible since the size and shape is recovered by cooling. No noticeable damage was observed after several cycles. The mechanical properties of the composite materials can be set by changing the hydrogel matrix. Four methods of material fabrication are described.