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The objective of this work was to functionalize with microcapsules of untreated and treated polyester fabrics with plasma and ozone. Plasma treatment was carried out using a corona discharge at 200 W, 400 w and 800 W with a constant gap between electrode and roll of 4 mm. For ozone treatment, polyester samples were exposed for 20, 30, and 45 min to ozone production by low-pressure mercury lamps. After plasma or ozone, lavender oil microcapsules were immobilized onto fabric by a conventional pad–dry–cure process, using citric acid as a crosslinking agent. The microcapsules were produced by complex coacervation between chitosan and arabic gum, with lavender oil in emulsion. The release showed that the ozone on the surface of PET (polyester) increased the affinity for the microcapsules, resulting in a greater adhesion of the microcapsules and, as consequence, more amount of oil to be liberated. On the other hand, the effect of the plasma treatment was related to physical etching, without a chemical change, and does not interfere with the affinity of the microcapsule, whose external layer is a polar polymer. The delay in the oil release from PET treated with plasma can also be related to the pore formation, which could retain the microcapsules and difficult the release of the oil. Ozone proved to be a good surface treatment to enhance the functionalization of the textile substrate, so that the oil release with time can be greatly improved.

Metal-organic frameworks are crystalline nanostructures formed by a metal interspersed by an organic binder. These metal-organic materials are examples of nanomaterials applied to textile material in search of new functionalized textiles. Cotton is a cellulosic fiber of great commercial importance, and has good absorption capacity and breathability; however, due to these characteristics, it is susceptible to the development of microorganisms on its surface. This work aims to analyze how the direct synthesis of HKUST-1 in cotton fabric modifies the chemical and physical properties. The material obtained was characterized by scanning electron microscopy to obtain its morphology, by spectrophotometry CIE L*a*b* to verify the color change, by a biological test to verify its resistance to microorganisms and, finally, by a unidirectional traction test to verify the change in its mechanical resistance. Thereby, it was possible to observe the formation of MOFs with the morphology of nanorods, and also, with regard to HKUST-1 in the cotton fabric, when applied, an elimination percentage higher than 99% was observed for both bacteria, E. coli and S. aureus. The presence of MOF was detected even after washing, however, the loss of 75% in the mechanical resistance of the material makes its potential for textile finishing unworkable.

The goal of this research was the development of cellulose-based biodegradable drug delivery systems solutions for cosmetic mask applications. Cellulose-based materials derived from natural renewable sources provide a sustainable alternative to nonwoven cosmetic masks derived from nondegradable fossil-based raw materials. An experimental design was executed to assemble the 3D cellulose fibres matrix and the water in oil emulsion comprising the active molecules from Mentha piperita L. Two types of biopolymeric additives were used, one derived from a nano/micro fibrillated cellulose pulp and another one including chitosan. A 3D computational simulation study was performed to enhance porosity and strength properties. The results indicated that the cosmetic face mask optimized prototypes, made from a biodegradable 3D matrix of cellulose fibres and active molecules, are suitable for dermic use. Keywords: biopolymers, dermic application, drug delivery systems (DDS), essential oil, Mentha piperita

Ethylene Propylene Diene rubber (EPDM), is present in many applications. However, its crosslinked structure makes difficult its recycling. The use of devulcanized EPDM, (dEPDM) as a component of elastomeric composites, is a real possibility to reuse EPDM scraps. In this study, three matrices (natural rubber (NR), styrene butadiene rubber (SBR) and EPDM rubber) have been tested including devulcanized EPDM as a recycled component. The EPDM previously was devulcanized using a thermomechanical process followed by microwave irradiation. The resulting devulcanized EPDM was blended with the matrixes and then the new compound was vulcanized again. The samples showed a general increase of their mechanical properties and their thermal stability specially marked for NR and SBR. Compositions including about 40 phr dEPDM within the EPDM matrix exhibited a difference in their general behavior that it was manifested by a general decrease in properties compared with lower amounts of dEPDM. In order to further understand this behavior, the samples were analyzed in terms of cross-link density, swelling degree, and scanning electron microscopy. The study of the microstructure of the samples indicated that microagglomerates of dEPDM are formed inside the samples. In case of NR or SBR the agglomerates were very linked to the matrix through the covalent bonds established in the crosslinking process. In the case of the EPDM matrix, the agglomerates presented less interfacial cross-links. The cross-linking takes place preferentially within the dEPDM microdomains and this results in a relative decrease in mechanical properties and thermal stability when compared to NR and SBR Authors thank the financial support from Ministerio de Ciencia e Innovación, project reference PID2021-126165OB-I00, corresponding to the 2021 call for Knowledge Generation Projects 2021

According to the Circular Economy Package promoted by the European directive, plastic bags companies must use in their formulations a percentage of polyethylene waste (industrial and/or domestic) greater than 70%. Following that regulation requires an understanding of its consequences in the final product from an industrial point of view. This manuscript analyzes the thermal and morphological changes related to the tear resistance of linear-low density polyethylene (LLDPE) samples from industrial waste generated by the company Sphere Spain subjected to the degradation produced by the recycling cycles. The process is analogue to the industrial, starts from samples in pellets then a film by blow extrusion is obtained (odd steps) and posteriorly this film is recycled to pellets again (even steps). The results obtained show that the LLDPE samples develop two crystalline structures (CS1 and CS2) which evolve differently through the recycling cycles with a tendency to decrease in crystallinity due to degradation that is not the same for the process of obtaining film or recycling to pellet. The molecules with a more linear structure and a longer chain break and branch. The more branched structure increases and tends to crosslinking. This leads to a decrease in tear strength in the longitudinal direction, which is not so evident in the transversal direction. The samples could admit four recycling cycles with and acceptable tear resistance. The longitudinal tear strength value decreases by 40% for each film and 20% in the case of tearing in the transverse direction. The results obtained in this research work show that the regulations included in the cited circular economy package can be applied in the manufacture of consumer bags, helping also to reduce the dependence of manufacturers on fluctuations in delivery by collapses in shipping.

Con este estudio se pretende analizar el comportamiento que presenta un LLDPE comercial, que se utiliza para la fabricación de bolsas, frente al proceso de degradación termo-oxidativa que sufre cada vez que se somete a un ciclo de procesado. La muestra de LLDPE se ha sometido a 10 ciclos mediante un ensayo en laboratorio con el que se pretende simular un proceso industrial, caracterizando los resultados mediante análisis térmico (DSC y TGA) y cromatografía de exclusión de tamaños (GPC). Se ha observado un comportamiento de degradación termo-oxidativa en dos fases, una primera durante los primeros ciclos de procesado en la que prácticamente no hay alteración de la estructura molecular del polímero gracias a la acción de los antioxidantes. Una segunda fase, a partir del 3er ciclo, en la que hay rotura de cadenas y formación de entrecruzamientos. Esto significa que en los primeros ciclos el polímero no sufre degradación, sino que se consumen los antioxidantes

Waste from pneumatic wheels is one of the major environmental problems, and the scientific community is looking for methods to recycle this type of waste. In this paper, ground tire rubber particles (GTR) from disused tires have been mixed with samples of low-density polyethylene (LDPE) and high-density polyethylene (HDPE), and morphological tests have been performed using scanning electron microscopy (SEM), as well as the dynamic electric analysis (DEA) dielectric characterization technique using impedance spectroscopy. From this experience, how GTR reinforcement influences polyethylene and what influence GTR particles have on the branched polyethylene has been detected. For pure LDPE samples, a Debye-type dielectric behavior is observed with an imperfect semicircle, which depends on the temperature, as it shows differences for the samples at 30 °C and 120 °C, unlike the HDPE samples, which do not show such a trend. The behavior in samples with Debye behavior is like an almost perfect dipole and is due to the crystalline behavior of polyethylene at high temperature and without any reinforcement. These have been obtained evidence that for branched PE (LPDE) the Maxwell Wagner Sillars (MWS) effect is highly remarkable and that this happens due to the intrachain polarization effect combined with MWS. This means that the permittivity and conductivity at LDPE/50%GTR are high than LDPE/70%GTR. However, it does not always occur that way with HDPE composites in which HDPE/70%GTR has the highest values of permittivity and conductivity, due to the presence of conductive fraction (Carbon Black-30%) in the GTR particles and their dielectric behavior.

The fight against nosocomial infections in hospitals, has promoted the use of microencapsulated essential oils on medical wearing uniforms. These types of microcapsules can be improved with the use of antimicrobial polymers in the shell structure. Chitosan is one of the most used biopolymers and the effectiveness of the treatment can be increased with the combination of different molecular weight chains of chitosan. This modification in the composition of shell structure allows controlling the rate of hydrolysis and, therefore the amount of its cationic form. The main objective of this work is to define a methodology to get microcapsules with different shell compositions, using surfactants as stabilizers in their first step. Once they have been obtained, these microcapsules will be fixed into textile substrates with the objective to use these tissues as surgical and medical clothes to spread the antibacterial effect, in sanitary staff, as well as in the own patient. In the process of microencapsulation the molecular weight distribution of polymers, influences strongly the delivery mechanisms of the active principle, as well as the chemical characteristics of the textile substrate used in every case. In this work, several chitosan biopolymers have been checked. Structural changes in the stabilization first step and the influence of the cross-linking extension have been related with the final antibacterial effect when fixed on cotton substrates Authors want to show their acknowledgements to the institutions and companies that helped to the development of this work. Spanish Ministry of Science and Technology. TEXBICO (RTI2018-094014-B-100) that granted the necessary funds to do the experimental work and Biomedical Chitosan (Australia) and CHIBIO (China), for kindly supply the samples used in the Shell structure of microcapsules

For the actual courses of surroundings conservation, segregation of oily water mixtures is increasingly desired. The hydrophobic/oleophilic cotton fabric as a system for removing oil from a water phase was prepared by reversible addition fragmentation chain transfer (RAFT) reaction technology. A piece of fabric was modified with the RAFT chain transfer agent S-1-Dodecyl-S'-(a',a''-dimethyl-a''-acetic acid) trithiocarbonate (CTA), then hydrophobic/oleophilic interface was fabricated on the CTA modified fabric by grafting the octadecyl methacrylate. The chemical structures, surface topographies and surface properties were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and contact angle experiments, respectively. The ability of as-prepared fabric with a separation efficiency was better than 97.0 % on average for various types of oil/water mixtures demonstrated the hydrophobic/oleophilic property. We believe that the work will extend the applications of fabric in the oil/water separation and provide a new design in practical applications

With the increasing awareness of environmental protection, the development and application of novel halogen-free flame retardants have attracted a lot of attention recently. 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- oxide (DOPO) and its derivatives are regarded as one of the most promising and widely used halogen-free flame retardants among various phosphorus-containing compounds due to its superior reactivity, thermal stability and oxidation resistance. Accordingly, DOPO-containing compounds have been incorporated with versatile polymeric matrices and exhibited advanced flame retardancy performances in gaseous phase and condensed phase

In this work, conventional sulfur and two types of organic peroxides (dicumyl peroxide (DCP) and di-(2-tert-butyl-peroxyisopropyl)-benzene (BIB)) curing systems were used to investigate the possibility for tailoring of the performance properties of GTR/NBR blends reinforced with a variable content of highly dispersive silica (0–30 phr). The curing characteristics, static mechanical and acoustical properties, swelling behavior, thermal stability, and microstructure of the prepared composites were investigated. The results show that regardless of the curing system used, increasing the content of highly dispersive silica resulted in the improvement of the mechanical properties of the studied materials. It was observed that sulfur-based systems are the best choice in terms of cross-linking efficiency determined based on torque increment and cross-link density parameters. However, further analysis of the physico-mechanical properties indicated that the cross-linking efficiency does not match the performance of specimens, and the materials obtained using organic peroxides show higher tensile properties. This is due to the improved physical interactions between the GTR/NBR matrix and highly dispersive silica when using peroxide systems. It was confirmed using the analysis of the Wolff activity coefficient, indicating the enhanced synergy.

El artículo caracteriza a nivel estructural, morfológico y térmico tres muestras distintas de óxido de grafeno comerciales (AGO, EGO y CGO) obtenidas mediante el método Hummers, las cuales han sido posteriormente reducidas (ArGO, ErGO y CrGO). Los resultados obtenidos demuestran que las muestras AGO y EGO son estructuralmente muy parecidas mientras que la muestra CGO es totalmente distinta. Los resultados de las muestras reducidas ponen de manifiesto que la estructura inicial del óxido de grafeno es determinante en el comportamiento térmico. El análisis morfológico mediante SEM indica que los GOs con mayor dispersión de grupos oxidados, son los que presentan una estructura laminar más precisa durante el proceso de reducción. La reducción de las muestras con baja dispersión de los grupos oxidados define estructuras menos laminares y más carbonáceas

The polyvinyl alcohol/graphene oxide (PVA/GO) hydrogel was prepared. It was confirmed that the adsorption performance of polyvinyl alcohol/graphene oxide hydrogel composite material was improved, and it does not cause secondary pollution. According to adsorption experiments, it was found that PVA/ GO adsorbent with a content of 30 % graphene oxide has the best comprehensive performance. The suitable environment of adsorption was under 25°C, 12-18 h for adsorption time and acidic conditions. The suitable adsorbent dosage was 0.3g and the suitable concentration of the dye was 10 mg/L The authors gratefully acknowledge the financial support of the Shaoxing Public Welfare Project (Grant No. 2017B70042), and the International Science and Technology Cooperation Project of Shaoxing University (Grant No. 2019LGGH1004)

In this work, the bulk and surface composition of Fe3O4 supermagnetic nanoparticles were modified for efficient epoxy curing. The bare, ethylenediaminetetraacetic acid (EDTA) capped, and cobalt (Co)-doped EDTA capped Fe3O4 nanoparticles were synthesized electrochemically. The crystalline structure and phase information, surface capping, morphology and magnetization behavior of nanoparticles were studied by X-Ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM) and vibrating sample magnetometer (VSM), respectively. A low amount of the prepared nanoparticle (0.1 wt.%) was used in preparation of epoxy nanocomposites. Nonisothermal differential scanning calorimetry (DSC) under different heating rates was performed to study the potential of nanoparticles in curing epoxy resin with an aliphatic amine. The heat release data on nanocomposites suggest that EDTA capped Co-doped Fe3O4 considerably improved the curing reaction between epoxy resin and the curing agent. Calculations based on Cure Index approved qualitatively a shift from Poor to Good cure by concurrent lattice and surface modifications of magnetic nanoparticles. It is bielived that the approach used in this work can pave the way to enhance curability of epoxy nanocomposites by the combined modification of bulk and surface of nanoparticles.

Raw hemp fibers are alkaline delignified to evaluate the effect of lignin on the moisture uptake behavior of hemp. Samples are subjected to moisture absorption/desorption isotherms from 5% to 95% relative humidity at three different temperatures (15, 25, and 35°C). The sorption ratio between delignified and untreated hemp is lowered by 25%. Hysteresis makes evident the greater influence of lignin on moisture binding at low relative humidity while at high relative humidity, cellulose plays the most important role. The GAB, Hailwood‐Horrobin and Dent models are fitted to absorption/desorption isotherms. Delignification and temperature decrease the size of the monolayer. The energy constants of the monolayer differ according to the model used. Lignin causes great differences between absorption and desorption. The greater the temperature is, the lower the monolayer energy constant. The energy constants of the multilayer are identical for the three models, showing a greater range of variation in delignified samples than in the untreated samples. Based on primary and secondary energy constants, bonding enthalpies are determined. Estimations in desorption show higher correlation coefficients with the energy constants, which enables to conclude that measures in desorption better explain the effect of delignification on the water uptake behavior of hemp., The authors gratefully acknowledge the financial support for this research from the Ministry of Science and Innovation of Spain through the MAT2016‐79352‐R Project, the contribution of ''Masias Maquinaria'' for the carding of hemp fibers and that of Mrs. Mercedes Simó for their support in the experimental work.

In this work, the phenomena involved in the microwave devulcanization of ground tyre rubber (GTR) were investigated. Three types of GTR with different content of organic compounds (elastomers, plasticizers, etc.), carbon black and ash have been studied. The chemical structure of GTR before and after a microwave devulcanization process was analyzed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Furthermore, the efficiency of the microwave devulcanization conducted at different treatment time was evaluated based on the values of crosslinking density and sol fraction content. FTIR spectroscopy results showed that devulcanization of GTR causes a decrease in carbon black with generation of CO2 due to its thermo oxidation, a decrease in the structural groups related to elastomeric components (mainly methylene and methine) and a breaking of CS groups and SS bridges. The presented results indicate the strong correlation between the content of SiO2 in the GTR and the achieved degree of devulcanization. It was observed that GTRs with a high content of SiO2 are devulcanized more easily than the samples with low content of SiO2, which suggest that the presence of silica fillers improve microwave devulcanization efficiency.

Microencapsulations protects the dye molecule from secondary reactions and release until contact with the fiber, triggered by stimuli. The procedure was performed using poly(lactic-acid-co-glycolic-acid), PLGA, and polyvinyl alcohol, PVA, and was confirmed via optical microscopy. UV-VIS spectroscopy assessed the efficiency of the encapsulation; and, the mathematical models of Korsmeyer-Peppas and Higuchi quantified controlled-release of dye. The microcapsules formed a core-shell structure, with a perfect sphere shape and homogeneous size. The release adjustments yielded the apparent diffusion coefficient

In biosensors fabrication, entrapment in polymeric matrices allows efficient immobilization of the biorecognition elements without compromising their structure and activity. When considering living cells, the biocompatibility of both the matrix and the polymerization procedure are additional critical factors. Bio-polymeric gels (e.g. alginate) are biocompatible and polymerize under mild conditions, but they have poor stability. Most synthetic polymers (e.g. PVA), on the other hand, present improved stability at the expense of complex protocols involving chemical/physical treatments that decrease their biological compatibility. In an attempt to explore new solutions to this problem we have developed a procedure for the immobilization of bacterial cells in polyethersulfone (PES) using phase separation. The technology has been tested successfully in the construction of a bacterial biosensor for toxicity assessment. Biosensors were coated with a 300 μm bacteria-containing PES membrane, using non-solvent induced phase separation (membrane thickness ≈ 300 μm). With this method, up to 2.3 × 106 cells were immobilized in the electrode surface with an entrapment efficiency of 8.2%, without compromising cell integrity or viability. Biosensing was performed electrochemically through ferricyanide respirometry, with metabolically-active entrapped bacteria reducing ferricyanide in the presence of glucose. PES biosensors showed good stability and reusability during dry frozen storage for up to 1 month. The analytical performance of the sensors was assessed carrying out a toxicity assay in which 3,5-dichlorophenol (DCP) was used as a model toxic compound. The biosensor provided a concentration-dependent response to DCP with half-maximal effective concentration (EC50) of 9.2 ppm, well in agreement with reported values. This entrapment methodology is susceptible of mass production and allows easy and repetitive production of robust and sensitive bacterial biosensors.

In this study, microcapsules containing different contents of different kinds of fragrances and with a regular spherical shape, 2,0–8,0 µm diameter, were synthesized in various core:shell ratios. Mint and cuir fragrances were successfully encapsulated in poly(urea-formaldehyde) (PUF) shell via in-situ polymerization. This was confirmed by optical microscope, scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) studies. By observation from thermogravimetric analysis (TGA), it was found a relation between thermal gravimetric curves and the amount of fragrance encapsulated, which was later contrasted by ultraviolet-visible spectroscopy. In this way, comparatively, the yield percentage values can be quantitatively defined with a sufficient degree of accuracy by TGA method

Ground tire rubber (GTR) was mechano-chemically modified with road bitumen 160/220 and subsequently treated using a microwave radiation. The combined impact of bitumen 160/220 content and microwave treatment on short-term devulcanization of GTR was studied by thermal camera, wavelength dispersive X-ray fluorescence spectrometry (WD-XRF), static headspace, and gas chromatography-mass spectrometry (SHS-GC-MS), thermogravimetric analysis combined with Fourier transform infrared spectroscopy (TGA-FTIR), oscillating disc rheometer and static mechanical properties measurements. The obtained results showed that bitumen plasticizer prevents oxidation of GTR during microwave treatment and simultaneously improves processing and thermal stability of obtained reclaimed rubber.

La electrohilatura se ha postulado como un método sencillo, versátil y escalable a nivel industrial que permite obtener nanofibras por aplicación de un campo eléctrico de alto voltaje entre la punta de una aguja, donde se deposita una gota de solución de un polímero, y un colector metálico. Uno de los campos de aplicación más prometedores de esta tecnología es el enfocado al desarrollo de soportes biomateriales para el sector biomédico. Sin embargo, el control de los parámetros del proceso es clave para la obtención de productos eficaces. En este sentido, este trabajo presenta un estudio sistemático del efecto de los principales parámetros de la electrohilatura que pueden afectar al diámetro de las fibras obtenidas, enfocado específicamente al desarrollo de soportes biomateriales de naturaleza proteica (gelatina y colágeno), por tratarse de substratos de similar naturaleza a los componentes fibrosos encontrados en las matrices extracelulares de los tejidos biológicos. Los resultados obtenidos indican que factores como el tipo de polímero, la concentración, el disolvente y la conductividad del colector tienen una influencia significativa en el diámetro final de las nanofibras. Sin embargo, no se observó influencia en el diámetro cuando se varió el voltaje, caudal y distancia al colector del sistema The electrospinning has been postulated as a simple, versatile and industrially scalable technique that allow the obtention of nanofibers by application of a high voltage electrostatic field between a metal capillary syringe, where a polymer solution drop is deposited, and a grounded collector. One of the most promising fields of application of this technology is focused in the development of scaffolds biomaterials for the biomedical sector. However, the control of the process parameters is crucial to obtain effective products. In this sense, this work presents a systematic study of the effect of the electrospinning main parameters that can affect the diameter of the obtained fibers, specifically focused on the development of protein based scaffolds, gelatin and collagen, since they are substrates of similar nature to the fibrous components found in extracellular matrices of biological tissues. The obtained results indicate that factors such as polymer type, concentration, solvent and collector conductivity have a significant influence on the final diameter of the nanofibers. However, no influence on the diameter was observed when the voltage, flow and distance to the collector were varied La electrofilatura s’ha postulat com un mètode senzill, versàtil i escalable a nivell industrial que permet obtenir nanofibres per aplicació d’un camp elèctric d’alt voltatge entre la punta d’una agulla, on es diposita una gota de solució d’un polímer, i un col·lector metàl·lic. Un dels camps d’aplicació més prometedors d’aquesta tecnologia és l’enfocat al desenvolupament de suports biomaterials per al sector biomèdic. No obstant això, el control dels paràmetres del procés és clau per a l’obtenció de productes eficaços. En aquest sentit,aquest treball presenta un estudi sistemàtic de l’efecte dels principals paràmetres de la electrofilatura que poden afectar al diàmetre de les fibres obtingudes, enfocat específicament al desenvolupament de suports biomaterials de naturalesa proteica (gelatina i col·lagen), per tractar-se de substrats de similar naturalesa a la dels components fibrosos trobats en les matrius extracel ·lulars dels teixits biològics. Els resultats obtinguts indiquen que factors com el tipus de polímer, la concentració, el dissolvent i la conductivitat del col·lector tenen una influència significativa en el diàmetre final de les nanofibres. No obstant això, no es va observar influència en el diàmetre quan es va variar el voltatge, el cabal i la distància al col·lector del sistema

This work reports the results obtained by the development of two types of nanocomposite membranes containing metal nanoparticles prepared by applying the Intermatrix Synthesis technique for the synthesis of silver nanoparticles in the ion-exchange matrices of sulfonated polyethersulfone-Cardo and Nafion membranes. The stability (in terms of silver nanoparticles loss) of the polymer-metal nanocomposites was evaluated by using both ultrasonic and thermostatic baths and appeared to be appropriate for their practical applications. The dual-function nanocomposites were characterized in batch tests, first, by monitoring their catalytic activity in the reduction of p-nitrophenol to p-aminophenol and second, by evaluating their antibacterial efficiency towards E. coli. The results of the catalytic tests have shown that polymer-silver nanocomposites demonstrate remarkably better activity in comparison with their polymer-palladium nanocomposite analogues. The same nanocomposites have been shown to permit the complete disinfection of E. coli containing water within a short period of time.

Stabilization of metal nanoparticles (MNPs) in polymeric matrices of different types has proven to be one of the most promising strategies to prevent their aggregation and to retain their properties. Polymer-stabilized MNPs (PSMNPs) and those based on polymer-metal nanocomposite materials are starting to find wide application in various fields of science and technology. In this paper, we demonstrate that metal-polymer nanocomposite membranes (MPNCMs) containing MNPs can easily be prepared in an ion-exchange such as, for example, sulfonated polyetherether ketone (SPEEK) matrix by using the polymeric membranes as nanoreactors for synthesis and to characterize the composition and structure of the formed MNPs. Metal ions (or metal ion complexes) are first incorporated into the polymeric matrix where they undergo reduction, leading to formation of corresponding MPNCMs. Since this technique allows successive metal loading-reduction cycles to be carried out, it enables synthesis of both monometallic and bimetallic (e.g., core-shell) MNPs. The proposed approach is illustrated by synthesis and characterization of MPNCMs containing both monometallic and bimetallic core-shell MNPs, formed by combinations of Pd, Pt, Co, Ni, and Cu, along with their application in electrochemical sensor and biosensor constructions.

Nafion is the first and the most well-known and commonly used ionomer membrane, applied nowadays in a broad variety of applications. This wide suitableness comes up in last instance from its chemical structure: a hydrophobic polytetrafluoroethylene backbone containing regularly spaced long perfluorovinyl ether pendant side chains ended by a sulfonic group. It is widely accepted that Nafion self-organizes in a membrane to form hydrophilic and hydrophobic domains in a way that is not yet perfectly understood. Despite there have been several models under debate, the pioneering cluster-network model (in which the polymer chains form reverse micelles with sulfonic groups lined in the wall and encapsulating water cavities) proposed by Gierke et al. is frequently reported in the literature. With the rise of Nanotechnology, a brilliant idea carne up less than two decades ago: the use of hydrated clusters as reactive vessels for the synthesis of a myriad of nanoparticles (NPs). Nevertheless, most of the works ascribed the formation of NPs to the cluster network model although most of the obtained NPs usually displayed diameters above the theoretical size of clusters and channels and that the local distribution of NPs seemed not to follow the original model. Lately, some authors, while studying the formation of NPs inside Nafion matrix, claim that all these disparities suggest that the role played by the flexible morphology of the polymer as well as the role of the solvent swelling the polymer have been oversimplified. Accordingly, this chapter will review the state-of-the-art of the several models describing Nafion's morphology and will provide a wide overview of their implication in the synthesis of NPs

LDPE/GTR/elastomer ternary blends with variable LDPE/GTR ratio and constant elastomer content were prepared via melt-compounding. Obtained LDPE/GTR/elastomer blends were applied as thermoplastic modifiers into bitumen. Microstructure, physical and thermal properties of the modified bitumen were determined. It was observed that chemical composition of LDPE/GTR/elastomer blends has significant influence on their density and rheological behavior, which are also main factors affecting the dispersion of LDPE/GTR/elastomer blends into bitumen matrix and interfacial interactions between used components. Microstructure and thermal behavior of modified bitumen confirmed that physical interactions between bitumen and LDPE/GTR/elastomer blends are limited with increasing content of GTR. This phenomenon is due to mainly cross-linked structure of GTR and its low flowability. The conducted investigations showed that interfacial interactions between of thermoplastic modifier and bitumen, therefore the conventional and thermal properties of modified bitumen can be improved and easily modified by changing composition of LDPE/GTR/elastomer blends.

Chicken feathers (CFs), waste from the poultry industry, were tested as biosorbent for colour removal of synthetic coloured water. Biosorption kinetics and isotherms were determined to provide an explanation to the physicochemical behaviour of the biosorption process of C.I. Acid Blue 80 dye on CFs. Up to 80% of the dye was biosorbed at 50°C demonstrating the biosorbent potential of the waste for the removal of organic dyes. Moreover, two mathematical approaches have been used to estimate the thermodynamic parameters such as the enthalpy, the entropy and the affinity of sorption. The first approach uses the Langmuir equation (affinity of sorption of 27,514 J/mol at 50°C) whereas the second approach calculates the affinity directly using the chemical potentials. In both cases, the affinity of the system is positive indicating that the biosorption process occurs spontaneously. In addition, the infrared spectroscopy and scanning electron microscopy results shown that the chemical structure and the morphology of the fibres were not significantly affected by the biosorption step

Production of hydrogen using aluminum and aluminum alloys with aqueous alkaline solutions is studied. This process is based on aluminum corrosion, consuming only water and aluminum which are cheaper raw materials than other compounds used for in situ hydrogen generation, such as chemical hydrides. In principle, this method does not consume alkali because the aluminate salts produced in the hydrogen generation undergo a decomposition reaction that regenerates the alkali. As a consequence, this process could be a feasible alternative for hydrogen production to supply fuel cells. Preliminary results showed that an increase of base concentration and working solution temperature produced an increase of hydrogen production rate using pure aluminum. Furthermore, an improvement of hydrogen production rates and yields was observed varying aluminum alloys composition and increasing their reactive surface, with interesting results for Al/Si and Al/Co alloys. The development of this idea could improve yields and reduce costs in power units based on fuel cells which use hydrides as raw material for hydrogen production.

A new method to produce high-purity hydrogen using photoelectrocatalytic reactions is studied. This integrated process uses solar energy and the Gibbs free energy of oxidation of organic wastes to help reducing the energy consumption of water electrolysis. The method diminishes the thermodynamic potential to 0.77 V and practical voltages to ca. 1.2 V, due to an electrocatalytic reaction in the presence of iron ions. The anolyte is illuminated, and separated from the catholyte by a proton exchange membrane. The process oxidizes water pollutants and avoids the anodic corrosion of a stainless steel anode, but not every sacrificial substance has a positive effect on it.

La particular estructura química de la matriz perfluorosulfónica del Nafion, con dominios hidrofílicos e hidrofóbicos segregados formando canales nanoscópicos, ha dado pie a su uso como modelo de estructura para la fabricación de nanocompuestos polímero-metal mediante el crecimiento de nanopartículas metálicas en su interior. En particular, mediante la técnica de síntesis intermatrical se ha conseguido el crecimiento de nanopartículas de plata (de un tamaño medio próximo a los 10 nm), las cuales presentan una distribución particular en forma de líneas casi paralelas, que difiere de la distribución más habitual de mayor concentración en la superficie. Para evaluar posibles aplicaciones de este nuevo material se ha realizado su caracterización mediante diferentes técnicas: microscop1ca, análisis químico superficial, mecánica, eléctrica/electroquímica. Los resultados obtenidos muestran que la presencia de nanopartículas no parece afectar significativamente al transporte de protones en la membrana, pero sí modifican la superficie de la misma. Además, la resistencia mecánica del nuevo material es inferior a la del Nafion no modificado debido a la interacción de las partículas con las cadenas de polímero. También se ha observado que algunas de estas propiedades varían de forma importante en/unción del grado de hidratación de la muestra. The particular chemical structure of Nafion, a perfluorosulfonic matrix with segregated hydrophilic and hydrophobic domains forming nanoscale channels, has led to its use as a model structure for the manufacture of polymer-metal nanocomposites by growing in it metal nanoparticles. in particular, using the technique of intermatrix synthesis, the growth of silver nanoparticles (with an average diameter close to 10 nm) has been achieved Moreover, samples exhibit a particular distribution of such nanoparticles in the form of nearly para/le/ fines, what differs from the usual major distribution on the membrane surface. To evaluate the potential application of this new material in electrochemical applications, we proceeded to their characterization by different techniques: microscopic, surface chemical analysis, mechanical and electrical/electrochemical. These results show that the presence of nanoparticles does not seem to significantly affect the transport of protons in the membrane bulk, but it modifies its surface. Furthermore, the mechanical strength of the new material is lower than the unmodified Nafion due to the high interaction between nanoparticles and polymer chains. Moreover, it was a/so observed that some of the mentioned properties significantly varied depending on the degree of hydration of the sample

In this communication, the synthesis of nanoparticles on anionic exchange polymers by the Intermatrix Synthesis method is reported. Monometallic (Ag) and core–shell metal/metal oxide (Ag@Fe3O4) nanocomposites were synthesized and characterized. Their magnetic and bactericidal activities were evaluated

This paper is dedicated to the further development of the Intermatrix synthesis (IMS) technique, which permits to produce a wide variety of polymer–metal nanocomposites (PMNCs) containing monometallic or bimetallic catalytically active polymer-stabilized nanoparticles (PSNPs) with the most favourable distribution of nanocatalysts inside the polymer, which is achieved by the purposeful application of the Donnan exclusion effect in the course of IMS. PMNCs containing low cost Cu-PSNPs can be used as an active element in construction of amperometric sensors for H2O2 detection. But, due to the high trend of copper nanoparticles (Cu-NPs) for oxidation under measurement conditions (in buffer solution) the sensors rapidly loose their sensitivity. The coating of Cu-NPs with platinum group metal-shell (PGMshell) of the minimal thickness results in the protection of Cu core against oxidation while maintaining the sensitivity of core–shell NP-modified sensors at sufficiently high level. The sensitivity of the sensors in the last case enhances when applying the step-wise formation of PGM-shell of higher purity by excluding the shell contamination with core-metal.

En raison de leurs grandes surfaces spécifiques les nanoparticules métalliques (N PM) possèdent des propriétés physico-chimiques uniques par rapport à la forme macroscopique du même matériau, en particulier en matière de réactivité catalytique. Afin de conserver ces spécificités, il est important de maitriser leur stabilité en évitant leur agrégation. La synthèse in situ, dite inter-matricielle, de NPM au sein d’une matrice polymère permet de les stabiliser sans perte de réactivité tout en conservant leurs propriétés catalytiques élevées. En utilisant cette stratégie de synthèse, nous avons développé des réacteurs membranaires catalytiques (RM C) contenant des NPM permettant ainsi de réaliser une réaction et une séparation lors d'un seul et même procédé. Les performances catalytiques des membranes ainsi obtenues ont été évaluées sur la réaction modèle de réduction du p-nitrophénol en 4-aminophénol par du borohydrure de sodium. Les membranes chargées en NPM de Palladium ont été testées en filtration frontale et ont montré une dégradation complète possible du p-nitrophénol. Metal Nanoparticles (MNPs) have unique phyico-chemical properties advantageous for catalytic applications which differ from bulk material. However, the main drawback of MNPs is their insufficient stability due to a high trend for aggregation. To cope with this inconvenience, the stabilization of MNPs in polymeric matrices has been tested. This procedure is a promising strategy to maintain catalytic properties. The aim of this work is the synthesis of polymer-stabilized MNPs inside functionalized polymeric membranes in order to build catalytic membrane reactors. First, the polymeric support must have functional groups capable to retain nanoparticle precursors (i.e. sulfonic). Then, nanoparticles can grow inside the polymeric matrix by chemical reduction of metal ions. The catalytic performance of developed hollow fibers has been evaluated by using the reduction of nitrophenol to aminophenol by sodium borohydride. Hollow fiber modules with Pd MNPs have been tested in dead-end and cross-flow filtration. Complete nitrophenol degradation is possible depending on operation parameters

The synthesis of polymer-stabilized nanoparticles (PSNPs) can be successfully carried out using intermatrix synthesis (IMS) technique, which consists in sequential loading of the functional groups of a polymer with the desired metal ions followed by nanoparticles (NPs) formation stage. After each metal-loading-NPs-formation cycle, the functional groups of the polymer appear to be regenerated. This allows for repeating the cycles to increase the NPs content or to obtain NPs with different structures and compositions (e.g. core-shell or core-sandwich). This article reports the results on the further development of the IMS technique. The formation of NPs has been shown to proceed by not only the metal reduction reaction (e.g. Cu 0 -NPs) but also by the precipitation reaction resulting in the IMS of PSNPs of metal salts (e.g. CuS-NPs).

Supported liquid membranes (SLMs) have demonstrated all along the years every high selectivity in facilitated transport of metal ions, however, they have some well known limitations, such as the gradual loss of the organic phase to the aqueous solutions. This paper describes two different types of novel membranes developed for the general purpose of separating and concentrating metal ions of interest in order to improve SLM physical and chemical characteristics. Both hybrid (organic—inorganic) membranes and activated composite membranes have been tested for the selective transport of Zn/Cd and Pt/Pd mixtures. For this purpose, different carriers have been used: 2-ethylhexyldithiophosphoric acid and 2-ethylhexylphosphoric acid for the separation of Zn and Cd whereas Aliquat 336 for Pt/Pd mixtures. The choice of these metal couples is related to environmental detoxification and catalyst recovery, respectively.

A novel arrangement for polymeric membranes used in anion-selective electrodes is presented. Sulfonated poly(ether ether ketone) (SPEEK), an ion conducting polymer has been used as a polymeric matrix to build an anion-selective electrode (ISE). A NO 3 − -ISE has been chosen as a model electrode to study the efficiency of the polymeric membrane. The effect of membrane composition and polymer compatibility with the electro-active components was investigated. The polymer matrix showed good mechanical properties and can be solvent cast in complete analogy to traditional ISE membranes. SPEEK matrix was studied in order to optimize both the potentiometric response and the selectivity of the electrode. The electrode exhibited a linear response with a slope of −51 mV per decade within the concentration range from 8.0 × 10 −5 to 2.5 × 10 −2 M nitrate ion. The detection limit was found to be 5.0 × 10 −5 M, and electrodes could be used over a wide pH range of 4–8. Finally, the sensor showed improved selectivity in comparison to some of the previously reported nitrate-selective electrodes.

The physical and chemical properties of metal nanoparticles (MNPs) are distinct from those of both bulk metal and isolated atoms. The main drawback of MNP is their instability and high trend for aggregation. Without stabilization they fuse together, losing their special shape and properties. The development of polymer-stabilized MNPs (PSMNPs) is one of the most promising solutions to MNP stability problem. In this paper we report in situ synthesis and characterization of PSMNPs, using the ion-exchange membranes as a nanoreactor. The membranes were prepared by using sulfonated poly(etherether ketone) of desired sulfonation degree (SD). The optimal SD provided a sufficiently high ion-exchange capacity and insolubility of the polymer in water and solubility in organic solvents (DMF). The membrane was loaded with metal ions (e.g., Cu2+) or complexes (e.g., [Pt(NH3)4]2+) followed by metal reduction inside the polymer matrix resulting in formation of either monometallic or bimetallic PSMNPs with core–shell structure. The MNP-containing membranes were characterized by electron microscopy to evaluate the morphological changes of the membranes and to estimate the MNPs size. The same membranes were also deposited on the surface of graphite–epoxy composite electrodes to study the electrochemical properties of polymer-PSMNP composites and to estimate their applicability in sensor designs. The presence of both Cu- and Pt/Cu-PSMNPs inside the membrane not only substantially improves the electric conductivity of the polymer, but also testifies to the clearly pronounced strong electrocatalytic activity of PSMNPs towards analyte under study (H2O2).

This work presents a comparative study between two different methods for the preparation of mediator-modified screen-printed electrodes, to be used as detectors in a reliable flow injection system for the determination of the nicotinamide adenine dinucleotide (NADH) coenzyme. The best strategy was selected for the final development of compact biosensors based on dehydrogenase enzymes. For the first immobilisation strategy, different redox mediators were electropolymerised onto the SPE surface. The second immobilisation strategy was carried out using polysulfone–graphite composites, which were deposited by screen-printing technology onto the screen-printed electrode (SPE) surface. Both methods achieved an effective and reliable incorporation of redox mediators to the SPE configuration. Finally, a flow system for ammonium determination was developed using a glutamate dehydrogenase (GlDH)-Meldola’s Blue (MB)-polysulfone-composite film-based biosensor. The stability of the redox mediators inside the composite films as well as the negligible fouling effect observed on the electrode surface improve the repeatability and reproducibility of the sensors, important features for continuous analysis in flow systems. Furthermore, the optimised bio/sensors, incorporated in a flow injection system, showed good sensitivities and short response times. Such a good analytical performance together with the simple and fast sensor construction are interesting characteristics to consider the polysulfone-composite films as attractive electrochemical transducer materials for the development of new dehydrogenase-based SPEs.

To date, poly(vinyl chloride) (PVC) is the most used polymer in the design of ion selective electrode (ISE) membranes. This paper is focused on the use of sulfonated poly(ether ether ketone) (SPEEK) as an alternative material to PVC for the design of ISEs. SPEEK of the desired degree of sulfonation is synthesized from poly(ether ether ketone) (PEEK). An NH4+-ISE has been chosen as a model electrode to study the efficiency of SPEEK as polymer matrix of the membrane. The material was evaluated in ionophore free ion exchanger membranes as well as in ion-selective electrodes membranes containing nonactine as ionophore. Analytical performance parameters of the prepared electrodes were evaluated. The electrodes show a slope between 50 and 60 mVdec(-1) depending on both the calibration medium and the membrane composition. A linear range of response between 10(-4) and 1.0 M and a lifetime of 1-2 months were obtained. The interferences of cations such us Ca2+, Na+, Li+ and K+ over the prepared ISEs are studied as well. Although the plasticizer in the SPEEK based membrane matrix is not necessary, its presence improves the sensibility. This makes SPEEK a good potential choice over alternative membrane matrices reported in the literature and a promising platform for the establishment of membrane components.

This paper reports the results on the further development of activated composite membranes (ACM) containing di-2-ethyhexyl-dithiophosphoric acid (D2EHDTPA) as a carrier. The selectivity and transport properties of D2EHDTPA based ACMs towards different metal ions including bismuth and zinc appear to be interconnected with each other. It has been shown that unlike the liquid-liquid extraction of bismuth, the use of D2EHDTPA-ACM permits to recover and to concentrate bismuth from a highly saline medium without irreversible destruction of the carrier. The difference in the rates of bismuth and zinc transport through ACMs permits their separation since the former is concentrated in the stripping solution and the latter retains in the feed compartment of the membrane cell.

10 pages, 7 figures, 1 table.-- Printed version published Oct 25, 2006.-- Issue title: "Eurosensors XIX - The 19th European Conference on Solid-State Transducers", This paper reports the results obtained by development of novel approaches for inter-matrix synthesis and characterization of polymer stabilized metal nanoparticle (PSMNP), which can be applied in molecular recognition devices (MRD) such as, sensors and biosensors. The proposed approaches are based on the use of functionalized polymeric membranes as a nanoreactor for both synthesis and characterization of PSMNP. The desired functionalization is achieved by either chemical grafting of functional groups to the polymeric matrix or by using physical immobilization of the metal-selective extractants inside the polymer by using solid-phase-incorporated-reagents (SPHINER) technique. In both cases the functional groups of either extractant or functional polymer are able to chemically fix metal ions or complexes inside the parent polymeric matrix prior to their reduction and formation of PSMNP. The results obtained by the inter-matrix synthesis and characterization of Pt- and Cu-PSMNP in polymeric membranes and on the use of these polymer-metal nanocomposite membranes as sensing elements in modified graphite-epoxy composite electrodes are reported and discussed., This work was supported by research grant BIO2003-06087 from the Ministry of Science and Technology of Spain, which is also acknowledge for the financial support of Dmitri N. Muraviev within the Program Ramon y Cajal. The Microscopy Service of the Autonomous University of Barcelona is acknowledged for their assistance.

Activated composite membranes (ACMs) containing di-(2-ethylhexyl) dithiophosphoric acid (D2EHDTPA) as a carrier have been found to facilitate the transport and separation of several cations. This paper describes an approach to the chemical characterisation of the transport phenomena of Zn2+, Cd2+, Cu2+, Ni2+, Sn2+ and In3+ by an ACM. The selectivity of D2EHDTPA based ACM towards different metal ions is presented and discussed focusing in Zn2+ and Cd2+ transport and recovery. Selectivity demonstrates that zinc ions are removable from mixtures due to the different extraction strength of D2EHDTPA. Such selectivity is based on the differences of the dynamic behaviour of the metal ions transport. In addition, a correlation of the chemical behaviour of those ACM systems with the corresponding solvent extraction systems has been found.

One of the routes to overcome the high instability of metal nanoparticles (MNPs) lies in the use of polymeric materials for their synthesis and stabilization. Besides, one of the most serious concerns associated with the growing production and use of MNPs is the possibility of their uncontrollable escape into the medium under treatment and the environment. A possible solution to this problem could be the synthesis of ferromagnetic MNPs with desired functionality, that might not only prevent their escape by using simple magnetic traps but also allow their recovery and reuse. In our work we report the results obtained by the development of environmentally-safe polymer-metal nanocomposite materials containing polymer-stabilized MNPs (PSMNPs) with properties. This material consists of a functional polymer with immobilized Pd@Co core-shell PSMNPs distributed mainly near the surface of the polymer which makes PSMNPs maximally accessible for reagents in catalytic applications. The material was characterized by different techniques to evaluate the total metal content, the size and the magnetic properties of MNPs and their distribution inside the polymer. All nanocomposites were tested as catalysts in Suzuki cross-coupling reactions between arylboronic acids and aryl halides to produce biphenyls as a reference reaction.

In this paper we report a comparative study of different procedures for the inter-matrix synthesis (IMS) of monometallic Pd-Polymer-Stabilized Metal NanoParticles (PSMNPs) in sulfonated polyetherether ketone (SPEEK) as stabilizing polymeric matrix. The IMS technique consists in consecutive metal loading-reduction cycles and can be realized by using two different versions: (i) in situ and (ii) ex situ. For in situ IMS the bare polymeric material is first deposited onto the electrode surface followed by metal loading and reduction. The last step (reduction of metal ions to PSMNPs) can be done either chemically or electrochemically. Pd-PSMNPs were synthesized by varying both the Pd concentration in the loading solution and the IMS procedure. MNPs were characterized by TEM, XRD, ICP-OES and EDS techniques and the main differences found are related to MNPs size and their spatial distribution inside the polymeric matrix. The catalytic activity of Pd-PSMNPs synthesized by different versions of the IMS technique was evaluated by using PSMNPs modified electrodes as amperometric sensors.

This paper describes the synthesis of copper nanoparticles (NPs) inside sulfonated polyetherether ketone (SPEEK) membranes, which serve both as reaction media for intermatrix synthesis (IMS) of Cu-NPs and as stabilizing matrices, preventing NPs aggregation and uncontrollable growth. The IMS technique involves the loading of the functional groups of the polymer with metal ions followed by their reduction inside the polymeric matrix. It has been shown that the repetitive metal loadingreduction cycle, in the case of copper, is accompanied by comproportionation reaction between Cu0 and Cu2+, leading to the formation of Cu +ions. This, in turn, allows for doubling the NPs content in the SPEEK matrix along with the tuning of Cu-NPs size.

The development of reusable dual-purpose nanocomposite foams for catalytic and bactericidal water treatment is reported. Small non-aggregated silver nanoparticles were made using Intermatrix Synthesis inside a polyurethane foam, which was chosen as a suitable polymeric matrix due to its high chemical and mechanical stability and industrial applicability. The antibacterial activity of the obtained nanocomposites was evaluated against suspensions of Gram-negative bacteria (E. coli), showing ideal bactericidal features for being applied to water disinfection. The catalytic activity of nanocomposites was also evaluated through a model reaction carried out under flow conditions. The possibility of reusing the catalytic material was evaluated in 3 consecutive cycles and, for all of them, no significant loss of efficiency was found. Moreover, the leakage of the active species to the media was evaluated under accelerated ageing conditions (3 h in an ultrasonic bath) and a negligible amount of silver was found outside the matrix. The chemical stability of the as-prepared nanoparticles was also evaluated by XANES and any modification in the chemical structure of silver nanoparticles was detected, even after storing the samples for two years under dry conditions.

Polysulfone (PS), a non-conductive polymer, is employed as an alternative material to polyvinyl chloride (PVC), the most used polymer in the design of ion-selective electrode (ISE) membranes to date. A nitrate-ISE is chosen as a model electrode to study the efficiency of PS as a polymer matrix of the membrane. Tetra-octyl ammonium nitrate is used as ionophore and 2-nitrophenyl octyl ether as plasticizer. The polymer/plasticizer/ionophore ratio is optimized and the analytical performance parameters of the prepared electrodes are evaluated. The electrodes show a slope between 45 and 60 mV/decade (depending on the calibration medium and membrane composition). A linear range response between 1.0 × 10 −4 and 3.0 × 10 −2 M, and a lifetime of at least 1 month are obtained. The electrodes exhibit good selectivity for nitrate in respect to other anions.

New hybrid membranes for metal ion transport were synthesized with the aim of improving mechanical and chemical stabilities, mean lifetime and loss of carrier. Hybrid organic–inorganic materials present several advantages with respect to organic and inorganic materials considered independently. Organic–matrix membranes usually have limitations related to chemical and thermal stabilities while organosilicone materials may present serious difficulties for film formation. The new membranes proposed here are based on a mixture of organic (cellulose triacetate, CTA) and organosilicone materials (dichlorodimethylsilane and tetraethoxysilane, DDMS and TEOS, respectively) as membrane support. Membrane preparation was optimized varying the amount of metal carrier (bis(2-ethyl hexyl phosphoric acid), D2EHPA) and plasticizer (2-nitrophenyloctyl ether, NPOE and/or tris(2-butoxyethyl)phosphate), TBEP). Total Reflection Infrared Spectroscopy, Scanning Electron Microscopy, Thermogravimetric Analysis, 29Si Nuclear Magnetic Resonance and X-Ray Diffraction were used to characterize the hybrid membranes and to correlate structural properties with permeability values for zinc metal ions.

In the present work, ground tire rubber (GTR) was mechano-chemically reclaimed at ambient temperature using two-roll mills. Road bitumen and styrene-butadiene-styrene (SBS)-modified bitumen at variable content (in range: 2.5–20 phr) were applied as reactive plasticizers to enhance reclaiming of GTR. For better understanding the plasticizing effect of bitumen on the quality of obtained reclaimed rubber, mechano-chemically reclaimed GTR has been compared with GTR after thermo-mechanical reclaiming via low temperature extrusion (120 °C), which allows generation of high shear forces on GTR. Reclaiming process was evaluated by oscillating disc rheometer measurements, followed by mechanical, physical, thermal, and morphological properties analyses performed on vulcanized reclaimed rubber. The obtained results showed that application of bitumen during mechano-chemical reclaiming of GTR improves processing and prevents oxidation of reclaimed GTR through enhancement of physical and chemical interactions between GTR and bitumen. On the other hand, high shear forces acting on GTR during thermo-mechanical reclaiming caused effective scission of cross-linking bonds, while at the same time an adverse oxidative degradation of GTR occurs. Noticeably, the type of bitumen strongly affected the nature of the interfacial interactions between GTR and bitumen. Plasticization/partial reclaiming of GTR (road bitumen, SBS-modified bitumen) and encapsulation of GTR (SBS modified bitumen) were confirmed by mechanical properties, FTIR, TGA and SEM measurements.

The particular chemical structure of Nafion with nanostructured and segregated hydrophilic and hydrophobic domains enables its use as a model structure for the manufacture of polymer–metal nanocomposites. Among such nanocomposites, samples of Nafion-117 containing Ag-NPs of ca. 10 nm prepared by Intermatrix Synthesis exhibited a particular distribution in the form of stripes, a regular pattern that could reveal the real morphology of the polymer. To evaluate the potential application of this engineered material (e.g. in electrochemical devices), these new nanocomposite membranes were characterized by different techniques: microscopic, surface chemical analysis, mechanical and electrical/electrochemical. X-ray (XRD and XPS) analyses combined with synchrotron experiments (XANES) were used to determine the chemical speciation of Ag in the membrane. Membrane potential and impedance spectroscopy measurements showed that such Ag-NPs did not hinder the diffusive transport of protons in the membrane bulk, moreover, they slightly reduced the electrical resistance in fully hydrated state samples. The mechanical evaluation of the nanocomposite evidenced a reduction of the elastic character when compared with the unmodified Nafion-117 sample.