Search

• MAA introduces unsaturated carboxylate metal salt bonds on the steel slag surface. • MAA etching of steel slag to make it loose and porous. • Steel slag can shorten the vulcanization molding cycle. • The performance of MAA-in-situ-m-SS filled natural rubber was significantly improved. • MAA-in-situ-m-SS can partially replace carbon black as a rubber filler. As a by-product of the steelmaking industry, the large-volume production and accumulation of steel converter slag cause environmental issues such as land occupation and dust pollution. Since metal salts of unsaturated carboxylic acid can be used to reinforce rubber, this study explores the innovative application of in-situ modified steel slag, mainly comprising metal oxides, with methacrylic acid (MAA) as a rubber filler partially replacing carbon black. By etching the surface of steel slag particles with MAA, their surface roughness was increased, and the chemical bonding of metal methacrylate salt was introduced to enhance their interaction with the molecular chain of natural rubber (NR). The results showed that using the steel slag filler effectively shortened the vulcanization molding cycle of NR composites. The MAA in-situ modification effectively improved the interaction between steel slag and NR molecular chains. Meanwhile, the physical and mechanical properties, fatigue properties, and dynamic mechanical properties of the experimental group with MAA in-situ modified steel slag (MAA-in-situ-m-SS) were significantly enhanced compared with those of NR composites partially filled with unmodified slag. With the dosage of 7.5 phr or 10 phr, the above properties matched or even exceeded those of NR composites purely filled with carbon black. More importantly, partially replacing carbon black with modified steel slag reduced fossil fuel consumption and greenhouse gas emission from carbon black production. This study pioneered an effective path for the resourceful utilization of steel slag and the green development of the steelmaking and rubber industries. [ABSTRACT FROM AUTHOR]

Heavy metals enter our environment through diverse resources, causing harmful effects owing to their inherent toxicity and facile migration into aqueous medium, becoming an environmental challenge. Among technologies able to remove these contaminants, the adsorption process emerges as a promising application for water treatment. Herein, functionalized silica magnetic nanoparticles using inorganic and organic have been employed as adsorbents to remove environmental hazards from wastewater effectively. Magnetic silicate core-shell amino-functionalized (Fe 3 O 4 @SiO 2 -AP) nanocomposites were synthesised using acrylic acid (AA) and para-aminobenzoic acid (PABA) as dual copolymer for Cd (II) removal. The characterization analysis confirmed the formed crystal nanostructure and the copolymers were chemically introduced in the magnetic silicate core-shell nanoparticle. The Cd (II) adsorption results on (Fe 3 O 4 @SiO 2 -AP) nanocomposites achieved an impressive q max of 32.50 mg/g at pH 8, adsorbent dosage of 3 g/L, and Cd (II) concentration of 100 ppm. The laboratory-scale fixed-bed column showed the breakthrough curves are flow rate independent, achieving metal removal of 99% for 405 min, at pH 8, influent ion concentration of 100 ppm, flow rate of 5 mL/min, and 1 cm bed height. The Freundlich model was the most suitable for fitting equilibrium data (R2 adj = 0.981) indicating a multi-layer adsorption phenomenon in the heterogeneous surface sites of the (Fe 3 O 4 @SiO 2 -AP) nanocomposites. The pseudo-second-order model (R2 adj =0.999) confirms that the adsorption rate depends on nanocomposites active sites and occurs by chemical sorption mechanism. The reusability adsorption-desorption experiments slightly decreased from 97.5 to 86.7% in the sixth cycle stability, demonstrating the material stability. [Display omitted] • Sustainable magnetic silicate core-shell amino-functionalised nanocomposites were synthesised. • Multi-layered adsorption by Cd(II)-nanoparticles complex interactions, breakthrough curves are independent of flow rate. • Fe 3 O 4 @SiO 2 -AP recovered by an external magnetic field-driven. • Adsorption was driven by hydrogen bonding and coordination bonds. • High material stability and reusability after the sixth cycle was achieved. [ABSTRACT FROM AUTHOR]

Calcium carbonate (CaCO 3) is the most frequently occurring scaling in process equipment including cooling water systems. In this work, the kinetics of CaCO 3 precipitation (CCP) was investigated using chemical method in the absence and presence of green inhibitors including polyacrylic acid homopolymer (PAA), poly maleic acid homopolymer (PMA), polyacrylic acid: 2-acrylamido-2- methylpropane sulfonic acid copolymer (AA/AMPS) and polyacrylic acid:2-acrylamido-2-methylpropane sulfonic acid: t-butyl acrylamide terpolymer (AA/AMPS/TBAA). The effects of the solution composition, temperature, pH, and type of inhibitor agent on the inhibition efficiency were examined. Results showed that increasing immersion time, in a solution without inhibitor, decreased the concentration of Ca2+ and solution pH. However, the inhibitor increased the inhibition efficiency up to 96 h. Also, the effect of temperature was examined on the precipitation kinetic, and it was found that the rate of scaling formation increases with the increase in temperature from 25 to 55 °C. Scanning electron microscope (SEM) and energy dispersive X-ray (EDX) illustrated that morphology of CCP changed and calcite and aragonite scaling occurred at 55 °C under the influence of amide, carboxylic and sulfonic groups of the inhibitors. Moreover, the kinetics scaling in the presence of PMA was investigated by the electrochemical method and was compared with the chemical methods. The results of the chemical method in the current work are more reasonable than the electrochemical method. The study provides new insights into the mineral scaling kinetics by identifying the known parameters dependence of CaCO 3 scale formation processes. [Display omitted] • The calcium carbonate (CaCO 3) scaling kinetics with and without inhibitors was studied. • Anti-scaling kinetics of PMA, PAA, AA/AMPS and AA/AMPS/TBAA green inhibitors were reviewed and compared. • The effect of temperature on kinetic of CaCO 3 scaling was investigated. • SEM and EDX analyses revealed morphological alterations in CaCO 3 scaling, highlighting the role of inhibitor groups. • A method comparison showed the chemical approach as more reliable than electrochemical methods in studying scaling kinetics. [ABSTRACT FROM AUTHOR]

Organic pollutants, such as dyes, contaminated water bodies seriously. Suitable materials and efficient technologies for degrading pollutants needed to be explored to protect the environment and human health. In this investigation, PVDF(PAA-g-β-CD)@TiO 2 hybrid film was prepared by a combination of "in situ hydrothermal-vapor induction" under mild conditions. The distribution, particle size, and interaction with the film surface for TiO 2 were investigated by XRD, XPS, SEM, and EDS. The TiO 2 nanoparticles were firmly immobilized and uniformly distributed on the hybrid film surface. Poly (acrylic acid) (PAA) and β-cyclodextrin (β-CD) on the film matrix were connected by the chemical bond, which provided stable nucleation and growth sites for TiO 2 while inhibiting photogenerated electron-hole recombination and significantly enhancing the adsorption ability. Furthermore, the multiple interaction forces (hydrogen bonding, coordination, and hydrophilic-hydrophilic interactions) between the film matrix and the TiO 2 were evaluated by simulated geometries and theoretical calculations. The multiple interactions reduced the band gap (Eg) while endowing the hybrid photocatalytic film with excellent degradation efficacy (η), stability, and recycling properties. Finally, the η of methylene blue (MB) reached 97.34 % within 120 min and remained above 90 % even after 8 reuses. It was believed that PVDF(PAA-g-β-CD)@TiO 2 film provided an approach for the mild preparation of polymer/TiO 2 hybrid film with high catalytic activity and optimization of photocatalytic properties. [Display omitted] • PVDF@TiO 2 hybrid membranes were fabricated by the "in situ hydrothermal-vapor induction". • The TiO 2 nanoparticles were immobilized and highly uniformly distributed on the membrane surface. • PAA and β-CD promoted charge transfer and boosted the "adsorption-photocatalysis" process. • The effects of the size and distribution of TiO 2 on the photoactivity were revealed. • The multiple interactions between TiO 2 and the matrix endowed the hybrid membrane with long-term stability. [ABSTRACT FROM AUTHOR]

Being a natural polymer with good biocompatibility and biodegradability, chitosan (CS) is often designed as a dual-network conductive hydrogel material. This is especially promising in the field of stretchable and flexible supercapacitors. The PbS/Ti 3 C 2 T x heterostructure is incorporated into the PAA/CS (PC) hydrogel using a two-step method, in which multiple hydrogen bonding interactions are constructed enable the PAA/CS/PbS/Ti 3 C 2 T x (PCPT) conductive hydrogel electrode material to possess a self-healing efficiency of up to 93% at room temperature. It also has a rich 3D pore structure that allows the PCPT conductive hydrogel electrode to reach a specific capacitance of 77.05 F/g at a current density of 10 mA/g. Even after 2000 cycles at a high current density of 200 mA/g, the specific capacitance remains at 89% of its original value. It has offered a new idea for the preparation of multiple-action self-healing electrode materials. • Enhanced performance using PbS/Ti 3 C 2 T x heterostructure as conductive fillers. • Boosted ion storage capacity of conductive hydrogels by PbS/Ti 3 C 2 T x heterostructure. • Multiple hydrogen bonds for enhanced toughness and self-healing properties. • Externally dissipating multiple hydrogen bonds to maintain the shape of hydrogels. [ABSTRACT FROM AUTHOR]

A coupling bath of circulating, chilled, degassed water is essential to safe and precise acoustic transmittance during transcranial magnetic resonance-guided focused ultrasound (tMRgFUS) procedures, but the circulating water impairs the critical real-time magnetic resonance imaging (MRI). An iron-based coupling medium (IBCM) using iron oxide nanoparticles previously developed by our group increased the relaxivity of the coupling bath such that it appears to be invisible on MRI compared with degassed water. However, the nanoparticles also reduced the pressure threshold for cavitation. To address this concern for prefocal cavitation, our group recently developed an IBCM of electrosterically stabilized and aggregation-resistant poly(methacrylic acid)-coated iron oxide nanoparticles (PMAA-FeOX) with a similar capability to reduce the MR signal of degassed water. This study examines the effect of the PMAA-FeOX IBCM on the cavitation threshold. Increasing concentrations of PMAA-FeOX nanoparticles in degassed, deionized water were placed at the focus of two different transducers to assess low and high duty-cycle pulsing parameters which are representative of two modes of focused ultrasound being investigated for tMRgFUS. Passive cavitation detection and high-speed optical imaging were used to measure cavitation threshold pressures. The mean cavitation threshold was determined in both cases to be indistinguishable from the degassed water control, between 6–8 MPa for high duty-cycle pulsing (CW) and between 25.5–26.5 MPa for very low duty-cycle pulsing. The findings of this study indicate that an IBCM of PMAA-FeOX nanoparticles is a possible solution to reducing MRI interference from the coupling bath without increasing the risk of prefocal cavitation. [ABSTRACT FROM AUTHOR]

In this study, polyacrylic acid grafted lutein (PAA-g-lutein) was prepared by hydrophilic modification of lutein with polyacrylic acid (PAA) through Steglish esterification method. The unreacted lutein was loaded in micelles formed by self-assembly of graft copolymers in water to form composite nanoparticles. The bioaccessibility and bioavailability of lutein nanoparticles were studied by in vitro and in vivo digestion experiments. Compared with free lutein, the saturated solubility and bioaccessibility of lutein nanoparticles were increased by 78 times and 3.6 times, respectively. The pharmacokinetics results in the mice model showed that the maximum concentration (C max) and area under concentration-time curve (AUC) of plasma of mice were increased by 3.05 and 6.07 times with lutein nanoparticles compared with free lutein. Meanwhile, the prepared lutein nanoparticles also promoted the accumulation of lutein in the liver, mesenteric adipose, and eyeballs. These results indicate that graft copolymerization of lutein with water-soluble polymers to form nanoparticles is an effective method to promote the bioavailability of lutein in vivo. Moreover, this method is simple and applicable, and can also be used for the modification of other bioactive molecules. [Display omitted] • The graft copolymer was synthesized by hydrophilic modification of lutein with polyacrylic acid by esterification reaction. • Nanocomposite particles were prepared by graft copolymer loaded lutein for self-assembly. • In vitro simulated digestion experiments indicated that lutein nanoparticles promoted the saturation solubility and bioaccessibility of lutein. • The pharmacokinetics results in the mice model proved that the modification improved the bioavailability of lutein and sustained release. [ABSTRACT FROM AUTHOR]

In this research, a novel method for manufacturing silicon (Si) nanoparticles (NPs) has been proposed. The process involves the use of ultraviolet (UV) irradiation and acrylic acid (AA) to induce Si NPs-AA polymerization. Si particles of varying sizes and an AA dispersion solution were subjected to UV radiation, leading to the formation of Si NPs coated with AA polymer, which separated to the top due to the volume increase. The Fourier-transform infrared (FT-IR) spectra confirmed the reaction between Si and AA by verifying the peak positions of the newly formed Si–C bond. The physical and chemical particle size measurements revealed that the Si NPs were surrounded by short-chain AA polymer clusters, accounting for approximately 15% of the cluster weight. Moreover, the Si particles' oxidation temperature in the Si NPs-AA cluster significantly decreased to about 450 °C. This technology holds promising potential for use in luminescent semiconductor materials, as it enables the selective separation of Si NPs. [ABSTRACT FROM AUTHOR]

Hydrogels with high strength are strongly needed to perform such operations as fluid plugging and water shutoff in the oil & gas industry. In this work, a new type of tough hydrogel consisting of the acrylic acid grafted nanocellulose network and the copolymer (AA-co-AM) network was synthesized via one-pot free-radical polymerization, and further cross-linked by using Al3+. The prepared dual-crosslinked double network hydrogel (DN-Poly -X-CNF-g-AA) showed the high compressive strength and toughness at low concentrations of nanocellulose (within 0.2 wt%), i.e., the maximum compressive strength was 2.5 MPa at strains of 90% and the recovery rates exceeded to 90% after 10 compressive cycles. Meanwhile, the grafted nanocellulose endowed the double-network hydrogels with the strong intermolecular forces and the well-ordered hierarchical structure, which exhibited a high thermal decomposition temperature, solid-like elastic behavior and a swelling suppression. Finally, the sand-pack plugging experiments showed that the double-network hydrogels could effectively plug the porous media with different permeability, in which the breakthrough pressure gradient was between 4.9 and 104.63 MPa/m. The results demonstrated that the obtained tough hydrogel has a great potential to be applied as soft materials for water shutoff and conformance control in reservoirs. [Display omitted] • A novel hydrogel consisting of the grafted nanocellulose and copolymer. • The grafted nanocellulose for double-network construction as low as 0.2 wt%. • The prepared hydrogel with the super-high compressive strength and toughness. • Tough hydrogel has high potential as a soft materials used for water shutoff. [ABSTRACT FROM AUTHOR]

Economy and safety are important factors for the layout design of chemical process plants. However, safety factors are often translated into economic indicators as a part of the objective function for layout optimization in previous studies. This may result in safety performance of chemical process plants does not meet the actual production requirements. In this paper, a multi-objective optimization method for chemical process plant layout is proposed to obtain series of solutions that can achieve the trade-off between economy and safety. The economic objective function is characterized by the total capital cost, including land cost, pipe cost, protection device cost and expected property loss from accidents. The safety objective function involves inherent safety which is evaluated by the Comprehensive Inherent Safety Index (CISI). The proposed multi-objective optimization model solved by non-dominated sorting genetic algorithm II (NSGA-II) is applied for layout optimization of an acrylic acid production plant. The results show a strong trade-off between competing economic and safety objectives according to the Pareto curve. The optimal solution ranges from 236,099 $ to 379,622 $ for total cost, corresponding to 87.7–132 for CISI. Safety will be improved significantly in the low-safety layout scheme when the capital investment increases slightly. [ABSTRACT FROM AUTHOR]

Acrylic acid (AA) is a versatile platform chemical of immense global demand. Today, the biorefinery is among the most promising initiatives of sustainably producing this commodity from bio-derived precursors. This study evaluated the economic and environmental performance of three production pathways to biobased acrylic acid using sugarcane A-molasses as feedstock. The 3 intermediates were lactic acid (LA), 3-hydroxypropionic acid (3-HP) and glycerol. Production scenarios were simulated in Aspen Plus ® software and resultant mass and energy flows provided inputs for subsequent estimation of the minimum selling price (MSP) and greenhouse gas (GHG) emissions. The MSP in US$/kg AA and the net GHG in kg CO2 /kg AA were the key metrics against which the performance of the developed scenarios were compared. Accordingly, the scenario using LA as intermediate emerged superior with an MSP that was 11 % higher than the actual market price for fossil-based AA. The same had an estimated net GHG emissions of 4.4 kg CO2 /kg AA. 3-HP was the second best performing intermediate with an MSP of 2425 US t-1 and green premium of 30 %. The 3-HP pathway, however, had a fairly low yield at fermentation of about 0.51 g LA/g glucose compared to the 1 g LA/gram glucose recorded by the LA pathway. Ultimately, glycerol proved to be an unattractive intermediate owing to a dismal product yield (0.50 g GLY/g glucose) as well as the cost and complexity of glycol recovery from the fermentation soup. [Display omitted] • Acrylic acid via lactic acid was preferred with an MSP of 2059 $t-1 and 11 % green premium. • Acrylic acid via 3-hydroxypropionic acid resulted in an MSP of 2425 $t-1 and 30 % green premium. • Acrylic acid via glycerol is economically unattractive (68–83 % green premium). • Increased 3-hydroxypropionic acid yield may result lower green premiums and MSP. • Acrylic acid via lactic acid has the lowest GHG emissions. [ABSTRACT FROM AUTHOR]

A combination of molecular modelling and experiments was conducted to study the separation of acrylic acid and propionic acid through extractive distillation with polar aprotic entrainers. It was found that acrylic acid and propionic acid can be efficiently separated through extractive distillation with a polar aprotic entrainer, resulting in the entrainment of acrylic acid and making propionic acid the most volatile compound. Vapour-liquid equilibrium experiments were conducted with 25 wt% acrylic acid, 25 wt% propionic, and 50% wt% entrainer. Dimethyl sulfoxide (DMSO) was found to induce the highest relative volatility of 1.56 at 25 mbar, which agrees well with the predicted value of 1.66 using the simulation software COSMO-RS. The difference in pKa (ΔpKa = 0.63) between acrylic acid and propionic acid is the main cause for the enhanced relative volatility. The corresponding difference in hydrogen bonding strength was calculated using COSMO-RS to result in ΔE = 1.8 kJ/mol at 25 °C between acrylic acid and propionic acid with the total mixture. When dodecane was selected as an entrainer, acrylic acid became the most volatile compound instead of propionic acid. This is explained by the fact that propionic acid has two extra hydrogen atoms available to have a Van der Waals interaction with the carbon atoms of dodecane. The difference in total Van der Waals interaction between the two carboxylic acids in the mixture with dodecane is 1.34 kJ/mol at 25 °C. This difference results in a relative volatility of 0.91, which is too small to be exploited in a distillation process, and it was concluded that for this mixture, DMSO was the best entrainer in the study. [Display omitted] ● Acrylic acid and propionic acid were separated by extractive distillation (ED). ● COSMO-RS and Spartan calculations predicted and explained relative volatilities. ● The ΔpKa of 0.63 is sufficient for entrainers to induce relative volatility in ED. ● DMSO induced a relative volatility of 1.56 at 25 mbar using 50 wt% entrainer. ● Alkanes reverse the relative volatility to 0.9. [ABSTRACT FROM AUTHOR]

[Display omitted] Compositions of doxorubicin with a terpolymer of N -vinylpyrrolidone, methacrylic acid and triethylene glycol dimethacrylate have been prepared and investigated by UV-VIS and NMR spectroscopy, cyclic voltammetry and DFT quantum chemical modeling. Oxygen containing groups of the terpolymer and hydrogen atoms of the drug OH and NH+ groups form hydrogen bonds. The compositions have lower cytotoxicity in vitro compared with that of free doxorubicin [ABSTRACT FROM AUTHOR]

[Display omitted] We prepared a novel nanogel consisting of poly(acrylic acid) (PAA) and pullulan (Pull) via a facile and green irradiation protocol. Synthesized nanogels were modified with bovine serum albumin (BSA) and folic acid (FA) and then loaded with doxorubicin (DOX) to obtain a delivery system with tumor-specific targeting ability and enhanced biocompatibility. In-vitro DOX release was investigated at different pH values, and it was found that DOX release was higher in acidic media, which is an advantage for the internalization of nanoparticles in acidic tumor environment. MTT assay and DAPI staining were performed to evaluate the effects of nanogels on L929 and MCF-7 cells. Based on the results of in vitro studies, DOX-loaded nanogels were found to be effective on cancer cells, while the neat ones were nondestructive in both lines. Overall, we envision that the biocompatible and tumor-specific nanogels could be a promising safe drug carrier system for cancer therapy. [ABSTRACT FROM AUTHOR]

Gelatin, being a naturally derived biomacromolecule shows good biocompatibility and biodegradability and hence turn out to be a potential biomaterial in synthesizing adhesive hydrogel. However, to achieve significant adhesive strength under wet condition and good mechanical properties, gelatin is functionalised with dopamine and acrylic acid. Here, inspired from nature, we have developed a gelatin based adhesive hydrogel for wet surfaces by incorporating dopamine into gelatin-poly(acrylic acid) chain. The synthesized hydrogel demonstrate good mechanical strength, high stretchability, reversibility, self-healing and dynamic adhesive behaviour along with long term reusability. The adhesive strength of the synthesized hydrogel to tissue surface was found to be 6.5 KPa when applied under submerged condition. Moreover, the swelling behaviour of the hydrogel reveals that hydrogel have limited swellability thereby retaining adhesive property under fully swollen state. Haemolysis results reveals the biocompatible nature of the hydrogel. Thus this hydrogel emerge to be a promising bioadhesive for application in various fields mostly in biomedical devices. [ABSTRACT FROM AUTHOR]

Hollow spherical silica film has been used on glass substrates as an antireflective coating, and PAA is one of the common templates for preparing SiO 2 films by sol-gel method. In this paper, the effects of polyacrylic acid (PAA) content on the SiO 2 films prepared by the sol-gel method were analyzed using TEM, DLS, XRD, IR, SEM, and the transmission spectrum. The sol containing hollow spherical micelles can be prepared well from tetraethyl orthosilicate (TEOS) as raw material and PAA as water-soluble polymer by improved Stober, and template method. With the increase of PAA content, the particle size of hollow spherical silica colloidal particles increases and the quantity decreases. The sol is attached to the surface of the soda lime glass substrate to form a film by dip-coating method. With the increase of withdrawal speed, the transmittance of the glass increases, and with the increase of PAA content from 0.1g to 0.6g, the sample's transmittance decreases first and then increases. [ABSTRACT FROM AUTHOR]

As an easily obtained organic waste, by-product acetic acid could be an appropriate co-substrate with blue algae wastes (increase C/N ratio of substrates) for co-fermentation of PHA production. However, there are still acrylic acid and other chemicals in by-product acetic acid, which could cause severe inhibition for fermenting microorganisms during PHA production process. The current study represented that alkali pretreatment (pH level of 12) is a more favorable method compared with thermal pretreatment (80 ℃ for 30 min) for breaking cell walls of blue algae. It seemed that there was no synergistic effect of the combination of thermal and alkali pretreatment methods (temperature of 80 ℃ and pH level of 12). Optimal parameters during electro-fenton process for removal of inhibitors in by-product acetic acid were under current of 0.5 A, pH level of 3 and reaction time of 120 min. Both the highest dry weight of PHA and PHA concentration were achieved by applying blue algae and by-product acetic acid (after pretreatment) as co-substrates (mixed ratio of 3:1, stirring speed of 200 r/min, 24 h), indicating that using by-product acetic acid (after pretreatment) as co-substrate could increase C/N ratio and promote PHA production successfully. The current study could offer new insights for improving PHA production by co-fermentation. [Display omitted] • Alkali pretreatment is a more favorable method compared with thermal pretreatment. • There was no synergistic effect of the combination of thermal and alkali pretreatment. • Optimal parameters for removal of inhibitors in by-product acetic acid were determined. • By-product acetic acid (after pretreatment) as co-substrate could promote PHA production. [ABSTRACT FROM AUTHOR]

Primary quasi-solid Al-air batteries using hydrogels have attracted increasing research attention owing to their high energy density, good handling, safety and reliability. However, it is still difficult to develop hydrogel electrolytes with high ionic conductivity and water retention owing to limited capacity of single material hydrogels. Herein, we report a hydrogel electrolyte of poly (acrylic acid) (PAA) is modified by κ-carrageenan (KC) for solid-state Al-air batteries. The result suggests that the hydrogels not only exhibit outstanding water retention but also high ionic conductivity, which is attributed to the amorphous phase and hydrophilic group of the KC. Additionally, the lifespan of solid-state Al-air battery is extended at a current density of 5 mA cm−2 owing to adding KC. Further, the lifetime of open Al-air batteries is improved by self-corrosion inhibition of Al anode. [ABSTRACT FROM AUTHOR]

A highly stable silicon microparticle (μSi) anode with high energy density is reported using a hybrid binder made of functionalized carbon nanotubes (FCNTs) and poly(acrylic acid) (PAA). The FCNTs with high electrical conductivity can be stably dispersed in water after partial oxidation of the carbon nanotubes (CNTs), forming a macroporous scaffold in an aqueous dispersion. By mixing the FCNT scaffold with PAA and μSi particles, FCNT/PAA uniformly encapsulates μSi and can be easily coated on Cu foil via a practical bar-coating method without the use of harsh solvents, stabilizers, or additional processes. The μSi-FCNT-PAA electrode exhibits stable performance, with an initial reversible capacity of 3560 mAh g−1 at 1C and a specific capacity of 1764 mAh g−1 at 200 cycles in a half-cell test. Full-cell test with NCM 712 cathode also shows stable capacity retention at 1C, exhibiting an initial reversible capacity of 170 mAh g−1 and a specific capacity of 81 mAh g−1 at 200 cycles. The FCNT network with enhanced mechanical properties due to the addition of PAA is effective in preserving the Si anode structure during cycling tests by enduring its volume changes and preventing thick solid-electrolyte interphase (SEI) layer formation. [Display omitted] • Anode was prepared with water soluble functionalized carbon nanotube (FCNT). • FCNT formed conductive network by encapsulating silicon microparticle (μSi). • Poly(acrylic acid) (PAA) enhanced flexibility and formation of conductive network. • Flexible conductive network suppressed pulverization and isolation of μSi. • The anode retained high capacity and long cycle stability in half/full cell system. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries are one of the promising next-generation energy storage devices for meeting the growing energy demands. However, their commercial application have been hindered by several problems including the insulating nature of sulfur species, the shuttle effect of polysulfides, and the sizeable volumetric change of sulfur cathode upon cycling. Herein, a hierarchical porous carbon aerogel embedded with small-sized TiO 2 nanoparticles (HPCA-TO) is prepared with polyacrylic acid grafted Ti 3 C 2 MXene as 2D template and TiO 2 source, chitosan as carbon precursor. HPCA-TO is filtrated onto a commercial polypropylene separator as a functional interlayer towards the sulfur cathode. For the HPCA-TO, the small-sized polar TiO 2 nanoparticles are beneficial for chemically reserving the soluble polysulfides, while the 2D carbon skeleton enables enhanced electrode conductivity, and the hierarchical porous structure can facilitate the ionic diffusion. As a result, the polysulfide shuttling is efficiently suppressed, and the conversion kinetics of polysulfides is largely enhanced. The Li–S batteries with the modified separators demonstrate a high initial discharge capacity (1439 mAh g−1 at 0.1 C) and excellent rate capability (502 mAh g−1 at 5 C). [Display omitted] [ABSTRACT FROM AUTHOR]

The stabilization and transport of the reactants, intermediates and products are significant to rational design of an industrial catalyst. In this work, we encapsulated the surface of Pd/g-C 3 N 4 catalyst with acrylic acid (AA) using a photo-induced grafting method to mimic the 3-dimensional nature of enzymes. A combined characterization and ab initio calculation revealed that AA ligands on the surface controlled the adsorption and diffusion behaviors of the reactants, rather than alter the electronic or geometric properties of Pd active centers. The optimized catalyst (Pd/CNA-4) significantly enhances isoprene partial hydrogenation activity without a decline in semi-hydrogenation selectivity. This approach can be further optimized by changing the types of the encapsulating ligands and can meet other specific catalytic reactions to regulate their conversion and selectivity and is therefore expected to extend to other areas of heterogeneous catalysis. In this work, we modified the support of Pd/g-C 3 N 4 with acrylic acid molecules and found that the optimized Pd/CNA-4 showed an improved isoprene semi-hydrogenation activity, reaching 8 times that of unmodified Pd/g-C 3 N 4 catalyst and 2.4 times that of commercial 5 wt% Pd/C catalyst, without obvious decline in partial hydrogenation selectivity or deactivation during 12-h test. Employing a combined characterization tool, this work revealed the mechanism of how the microenvironment confined by acrylic acid ligands influences the nature of the Pd active centers, as well as the adsorption and diffusion behaviors of the reactants. [Display omitted] [ABSTRACT FROM AUTHOR]

The performance of a thermoelectric device fabricated with centimeter-scale monolayer graphene (active size, ∼7 × 1 cm2) was investigated in this study. The carrier type and junction profile of the active graphene layer were modulated by chemical doping. After device optimization, improvements in carrier concentration of at least 200%, which led to enhancements in power factor of at least 600%, were obtained. Under optimal performance conditions, a maximum Seebeck coefficient of ∼350 μV/K and power factor of ∼14000 μW/mK2 could be achieved under a temperature difference of 18 K. These thermoelectric parameters are at least three times higher than the best values reported for organic or other graphene-based thermoelectric devices. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Vinyl ester resin can be degraded in GVL-H 2 O solvent with PTSA catalyst. • The ester bonds of vinyl ester resins were cleaved via hydrolysis. • Recycled bisphenol-A diglycidyl ether was cured into polyurethane. • Amphiphilic PTSA catalyst facilitates itself entrancing into the matrix of VER. Vinyl ester resins (VER) and its composites are widely used in chemical industry and municipal engineering. However, its dense three-dimensional network structure makes its degradation and recycling a great challenge. Herein, a novel, efficient and green degradation system gamma-valerolactone (GVL)–H 2 O/p-toluene sulfonic (PTSA) was developed to degrade VER and its composites. VER was completely degraded in the GVL-H 2 O/PTSA at 210 °C and 0.6 MPa. By combing SEM-EDS, IR, NMR, GPC and MALDI-TOF-MS analysis, it was clarified that VER swelled well in GVL, allowing the transfer of PTSA and H 2 O through the resin matrix. The ester bonds in VER were cleaved via hydrolysis with H 2 O catalyzed by the sulfonic acid of PTSA, and high value-added polymer products, i.e., copolymer of styrene and methacrylic acid (SMAA) and bisphenol-A diglycidyl ether (DGEBA), were recycled, which accounted for ca. 87.0 wt% of raw VER. DGEBA can be recycled to prepare a new PU material. The GVL-H 2 O/PTSA system was also effective for degrading UPR and VER-containing composites. This work provides a practical strategy for chemical degradation and recovery of thermoset VER resins. [ABSTRACT FROM AUTHOR]

Hydroxypropyl cellulose (HPC) hydrogel is a promising material for fabricating energy saving smart windows. However, its lower critical solution temperature (LCST = 42 °C) is much higher than comfortable room temperatures. In this work, we applied surface polymerization of acrylic acid (AA) monomers on HPC chains and synthesized HPC-polyacrylic acid (PAA) hydrogels with precisely controllable LCST in the range of 23.0–42.0 °C. The fabricated HPC-PAA hydrogel smart windows exhibited excellent T lum , 22 °C of 91.8% and ΔT sol , 22–40 °C of 73.7%, outperforming VO 2 hydrogel composites and photothermal nanoparticles doped hydrogel smart windows. Meanwhile, cesium tungsten bronze (Cs 0.32 WO 3) photothermal nanoparticles can be introduced to the HPC-PAA hydrogel matrix, and the near infrared (NIR) shielding ability of Cs 0.32 WO 3 allowed significant reduction of NIR transmittance of the smart windows from 81.7% to 41.6% at 22 °C, and from 19.3% to 3.6% at 40 °C. Temperature regulation tests in model houses revealed outstanding heat-shielding performance of Cs 0.32 WO 3 (0.4 wt %)/HPC-PAA hydrogel smart windows, especially compared with ordinary double-glass windows. Furthermore, the HPC-PAA hydrogel and Cs 0.32 WO 3 (0.4 wt %)/HPC-PAA hydrogel are non-toxic, biocompatible, low-cost, suggesting their suitability for energy-saving smart window applications. [ABSTRACT FROM AUTHOR]

Difficult-to-treat wastewater discharged from printing and dyeing industries has posed an environmental risk. Three-dimensional porous structures exhibit excellent dye adsorption properties. In this study, chitosan (CTS) was introduced in situ on polyamidoamine (PAMAM). Then, the composite gels containing sodium alginate (SA)/CTS in situ grown on PAMAM/polyacrylic acid (SCPP-Gn (n = 0,1,2,3)) were prepared with a controllable structure using a semi-dissolution acidification sol-gel transition method (SD-A-SGT). Owing to the stronger mechanical strength and larger specific surface area, the SCPP-G2 composite gel has the higher stability and the greater adsorption capacity for dyes, with maximum adsorption capacities of 325.21 mg/g for rose bengal (RB) and 222.40 mg/g for sunset yellow (SY). The mechanism study showed that the adsorption toward RB and SY was dominated by chemical adsorption. After five adsorption-desorption cycles, it was found that 70 % of the initial adsorption capacity could be retained. Our study demonstrates the great potential of the SCPP-G2 composite gel as an adsorbent in water treatment. • SCPP-G2 gel structure was controllable and stable by SD-A-SGT method. • CTS in situ growth of different generations of PAMAM was used in the gels. • The differences of dyes adsorption capacity among different generations of gels • Adsorption competition experiment of binary mixed dyes by SCPP-G2 gel was analyzed. • SCPP-G2 gel as an effective low-cost adsorbent could be regenerated and reused. [ABSTRACT FROM AUTHOR]

In the present work, carboxymethyl cellulose (CMC) was used to develop hydrogels as adsorbents for wastewater treatment applications due to its surface functionality and modifiable characteristics. Hydrogels (Hyd) were synthesized by grafting copolymers of acrylic acid (AA) and itaconic acid (IA) onto the CMC backbone by free radical polymerization method in order to remediate Fuchsin from aqueous solution. The presence of CMC in copolymer hydrogel of AA and IA (Poly(AA- co -IA)) up to 14.29 wt% enhances equilibrium swelling and removal efficiency. Different novel nanocomposite hydrogel samples were prepared by varying weight percentages of carbon black (CB) nanoparticles in the range of 0 to 12.5 wt%. The addition of CB up to 5 wt% enhanced the swelling and removal efficiency of the Hyd. Brunauer–Emmett–Teller (BET) test gave the surface area of 0.615, and 0.890 m2/g for Hyd and Hyd/CB, respectively, indicating that incorporation of CB led to a significant increase in Hyd surface area. The Maximum removal efficiency of Fuchsin under the optimum conditions was obtained to be 83.33, 93.54, and 98.76 % for Poly(AA- co -IA), Hyd, and Hyd/CB, respectively. The kinetic study showed that the pseudo-second-order is the best-fitted model. Isotherm studies showed that equilibrium data have a good fitness with the Langmuir model with R2 of 0.978, 0.992, and 0.982 for Poly(AA- co -IA), Hyd, and Hyd/CB, respectively. The Langmuir model gave an adsorption capacity of 26.99, 31.6, and 33.75 mg/g for Poly(AA- co -IA), Hyd, and Hyd/CB, respectively. Also, the value of n and R L parameters demonstrated that the adsorption process is physical and favorable for adsorbents. The study of thermodynamic parameters illustrated that the adsorption of Fuchsin using adsorbents is a spontaneous, exothermic, and entropy-decreasing process. Regeneration study showed that CMC-based hydrogels have higher performance in ad(de)sorption cycles than Poly(AA- co -IA) and the addition of CB to the Hyd matrix enhances reusability. Overall, Hyd and Hyd/CB can be used as promising adsorbents for the remediation of Fuchsin due to high swelling and adsorption capability. [Display omitted] • The optimized wt.% of carboxymethylcellulose in hydrogel based on swelling and removal efficiency was obtained to be 14.29. • Incorporation of carbon black into hydrogel enhances swelling and removal efficiency. • Under optimum adsorption conditions, 98.76 % of dye is removed by nanocomposite hydrogel. • The kinetic and isotherm data are well fitted to pseudo-second-order and Langmuir models, respectively. • Carboxymethyl cellulose-based hydrogels showed higher efficiency in reusability. • Fuchsin is adsorbed via electrostatic interaction, hydrogen bonding, and л-л interaction. [ABSTRACT FROM AUTHOR]

With the rapid development of the textile industry, a large amount of dyeing wastewater discharge has caused great harm to the ecological environment. In this work, a dual-network, composite hydrogel adsorbent with excellent mechanical properties, good reusability, and large adsorption capacity was prepared by introducing chitosan cross-linked polyvinylamine into the N , N ′-methylenebisacrylamide cross-linked polyacrylic acid network. The dual cross-linking network gave the hydrogel excellent mechanical properties with maximum tensile stress and strain up to 1.9 MPa and 920 %. The adsorption capacity of methylene blue on hydrogel was up to 596.14 mg/g. In addition, the prepared hydrogel exhibited good reusability, and their adsorption efficiency remained above 85 % in five consecutive cycles. The adsorption behavior was well fitted by Pseudo-second-order kinetics and the Langmuir equation, indicating that the hydrogel was chemisorbed to the dye as a monolayer. The adsorption mechanism analysis showed that the electrostatic interactions and hydrogen bonding between the functional groups of the hydrogels and methylene blue molecules contributed to the good adsorption capacity. Overall, the synthesized composite hydrogels could be used as an efficient adsorbent for the removal of methylene blue dye, particularly from textile industry wastewater. [Display omitted] • Poly(acrylic acid)/chitosan-g-polyvinylamine composite hydrogel was prepared as adsorbent. • The adsorption of composite hydrogels relies on hydrogen bonding and electrostatic interactions. • The composite hydrogels exhibit ultra-high mechanical properties with strong tensile stresses and strains. • Langmuir isotherm and Pseudo second-order kinetic were in agreement with adsorption data. • After five adsorption cycles, the composite hydrogel still achieved 85.24 % removal of methylene blue. [ABSTRACT FROM AUTHOR]

Currently, hydrogel sensors for health monitoring require external tapes, bandages or adhesives to immobilize them on the surface of human skin. However, these external fixation methods easily lead to skin allergic reactions and the decline of monitoring accuracy. A simple strategy to solve this problem is to endow hydrogel sensors with good adhesion. Inspired by the starch paste adhesion mechanism, a biomass-based hydrogel with good conductivity and high repetitive adhesion strength was prepared by introducing modified starch into polyacrylic acid hydrogel system. The properties of biomass-based hydrogels could be controlled by changing the proportion of amylose and amylopectin. The biomass-based hydrogel exhibited a variety of excellent properties, including good stretchability (1290 %), high adhesion strength (pig skin: 46.51 kPa) and conductivity (2.3 S/m). Noticeably, the repeated adhesive strength of biomass-based hydrogel did not decrease with the increase of adhesion times. The strain sensor based on the biomass-based hydrogel could accurately monitor the large-scale and small movements of the human body, and had broad application prospects in the field of flexible wearable devices. [Display omitted] • The biomass-based hydrogel exhibits excellent elongation at break (1290%), conductivity (2.3 S/m) and strain sensitivity. • The adhesion strength of biomass-based hydrogel does not decrease significantly with the increase of adhesion times. • The biomass-based hydrogel sensor can accurately monitor various subtle or large movements of the human body. [ABSTRACT FROM AUTHOR]

In this study, an interpenetrating double-network hydrogel (LMP/AA/PVAH) was prepared based on low methoxy pectin (LMP), acrylic acid (AA) and polyvinyl alcohol (PVA). The first rigid network of chemical crosslinking was constructed via free radical polymerization of LMP and AA, and the second of ductile physical crosslinking network was constructed via cyclic freeze-thaw of PVA. The first cycle hardness and elasticity of the LMP/AA/PVAH significantly increased from 13.08 N and 0 to 24.28 N and 0.79, respectively, when the second network structure was constructed in the hydrogel by PVA. Besides, the PVA network might enhance the ductile and limit the swelling of hydrogel. In addition, the adsorption properties of LMP/AA/PVAH were evaluated by adsorption of methylene blue (MB). The adsorption behavior of MB by LMP/AA/PVAH conformed to the pseudo-second-order kinetic model. Besides, after 4 cycles of adsorption, there was no significant difference in adsorption capacity of LMP/AA/PVAH. The results showed that LMP/AA/PVAH had good reusability. [Display omitted] • It was constructed a double-network hydrogel based on low methoxy pectin. • The mechanical properties of double network hydrogel were significantly higher than that of single network hydrogel. • Hydrogel LMP/AA/PVAH had good repeatability. [ABSTRACT FROM AUTHOR]

In order to prepare high ionic conductivity and robust mechanical properties of alkaline solid polyelectrolyte (ASPE) for applications in flexible wearable devices, a co-continuous structure membrane was designed using in-situ polymerization to introduce cross-linked polyacrylic acid (N-PAA) into the cellulose network constructed by regenerated degreasing cotton (RDC). The resultant ASPE membrane showed high ionic conductivity (430 mS·cm−1 at 25 °C), strong mechanical properties, and excellent alkaline stabilities, proving the viability of cellulose for use in energy storage systems. Surprisingly, the sandwich-shaped zinc-air battery assembled using RDC/N-PAA/KOH membranes as electrolytes exhibits superior values of cycling stability, discharge time, specific capacity (731.5 mAh·g−1), peak power density (40.25 mW·cm−2), and mechanical flexibility. Even under bending conditions, the zinc-air batteries still possess stable energy supply performance, suggesting this novel solid polyelectrolyte has promising application for wearable technology. [Display omitted] • Alkaline solid polyelectrolyte with co-continuous structures is prepared. • High ionic conductivity and excellent mechanical properties are achieved. • Zinc-air batteries in the bent state exhibit reliable performance. • Supercritical drying technology and in-situ polymerization methods are employed. [ABSTRACT FROM AUTHOR]

This work firstly proposed novel processes synthesizing hydroxypropyl acrylate (HPA) from diluted aqueous acrylic acid (AA) and propylene glycol (PG). As both AA and HPA dimerize, the key in process design is to hold the one-pass conversion low, and the product selectivity high. Herein, three process schemes using different strategies in enhancing selectivity, or handling recycle streams, were investigated. These include the conventional reaction/distillation configuration (Scheme 1), the intensified process using a side reactor (Scheme 2), or multiple side reactors with feed splitting (Scheme 3). After optimization, it was found that scheme 3 exhibits the greatest economic and environmental attractiveness, which reduces 43.4 % of cost, and 13.8 % of CO 2 emission from scheme 1. From the optimized scheme 3, the minimum required selling price (MRSP) of HPA (Target: 20 % internal rate of return, or IRR) is in between 1.904 and 2.797 USD/kg under varying raw material prices (i.e. diluted AA= 0.566–1.140 USD/kg; PG = 1.148–1.403 USD/kg). These results reveal the improvement from the current technology of producing HPA (i.e. current price: 2.725 USD/kg). Finally, a control structure was proposed onto the optimized Scheme 3. It satisfactorily rejects the disturbances from feed flowrate, feed composition and catalyst deactivation. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, MgO-doped CNC-g-PAA hydrogel was synthesized by grafting poly (acrylic acid) (PAA) onto cellulose nanocrystals (CNC) and then doped Magnesium oxide (MgO) using pH 7.0 and 12.0 to obtain an efficient nanocomposite hydrogel for antibacterial and anti-cancer activities. The synthesized nanocomposite hydrogels were evaluated by detailed characterization and confirmed the formation of a well-interconnected porous structure. MgO/CNC-g-PAA (pH = 12.0) exhibited improved bactericidal tendencies towards gram-negative and gram-positive bacteria, which was further investigated by in-silico molecular docking analyses and also examined the reactive oxygen species production by photocatalysis and free radical-scavenging assay. After this, Doxorubicin (DOX), a model anticancer drug, was successfully loaded into nanocomposites (∼79 %) by electrostatic interaction and confirmed pH-triggered based release, which was over 53.7 % in 24 h. Finally, in vitro cytotoxicity-based analysis confirmed the improved antitumor efficacy of nanocomposite hydrogels. These findings revealed that MgO/CNC-g-PAA hydrogels might be prospective carriers for controlled drug delivery. [ABSTRACT FROM AUTHOR]

Hydrogels with fascinating adhesion have been demonstrated great potential in various applications. However, most hydrogels lose their adhesion in wet or underwater environments due to the influence of interfacial water. Inspired by mussel, an underwater adhesive hydrogel was facilely fabricated by introducing electrostatic interactions, which consisted of poly (acrylic acid) (PAA), quaternized xylan (QAX) and tannic acid (TA). In this hydrogel, -COO− from PAA, -N+(CH 3) 3 from QAX and catechol group from TA resembled amino acids with negative and positive charges and 3,4-dihydroxyphenylalanine units in mussel, which endowed the hydrogels with great underwater adhesion through multiple interactions. Notably, acrylic acid (AA) played a key role in the dispersion of the system. QAX, a biomass derived from plants with excellent properties, worked with PAA to construct hydrogel networks. The resultant hydrogels exhibited excellent mechanical properties including remarkable stretchability (>4000 %) and compressibility. Moreover, the hydrogels had superior UV-blocking (~99.96 %), and showed good adhesion both in air and underwater. The hydrogels can be exploited as a wearable sensor to monitor human motions and even subtle motions, which have the potential to be explored in human health monitoring. • Biomass-based hydrogels are prepared by one-step polymerization. • Excellent adhesion UV blocking and mechanical property are realized. • Human motions and even subtle motions could be monitored. [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis and characterization of gelatin/κ-carrageenan crosslinked polyacrylic acid hydrogel (GT-CAG-cl-polyAA) and graphene oxide incorporated hydrogel nanocomposite (GO HNC) through a free radical crosslinking pathway. Under optimized reaction conditions, GT-CAG-cl-polyAA displayed 486 % maximum swelling percentage. TEM image depicted wrinkled silk veil wave-type surface morphology of graphene oxide (GO), whereas, the SEM analysis indicated the porous nature of the GT-CAG-cl-polyAA and GO HNC capable of accumulating a large number of water/dye molecules. GT-CAG-cl-polyAA exhibited 96.11 % and 82.16 % dye removal potential for the adsorption of methylene blue (MB) and coomassie brilliant blue (CB), respectively under optimized conditions. GO HNC enhanced the % dye removal efficiency (98.39 % for MB and 94.50 % for CB). The maximum adsorption capacity of GO HNC for the removal of CB and MB was 312.7 mg/g and 94.9 mg/g, respectively. The adsorption of CB and MB exhibited best fitting with Flory-Huggins adsorption isotherms data. The negative values of ΔG ° and positive values of ΔS ° which were obtained from the adsorption isotherm plot suggested the thermodynamic feasibility of the adsorption. Also, the samples were reusable for up to five consecutive cycles without any degradation and hence suggested a considerable pathway for the separation of textile dyes. [Display omitted] • Environmentally benign fabrication of graphene oxide based hydrogel nanocomposite • Efficient removal of MB (Xe = 312.7 mg/g) and CB (Xe = 94.9 mg/g) • Higher dye removal efficiency than many of the existing adsorbents • The synthesized samples were recyclable upto five consecutive cycles. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the influence on MMP inhibition, dentin adhesion and physicochemical properties of an adhesive system incorporated with polymerizable collagen crosslinker monomer derived from cardanol. The intermediary cardanol epoxy (CNE) was synthesized through cardanol epoxidation, followed by synthesis of cardanol methacrylate through methacrylic acid solvent-free esterification. Zymographic analysis was performed to evaluate the substances' ability to inhibit gelatinolytic enzymes. Collagen crosslinkers were added into adhesives systems according to the following groups: Ybond Universal® (Control), Ybond® + 2 % proanthocyanidin (PAC), Ybond® + 2 % unsaturated cardanol (Cardanol) and Ybond® + 2 % cardanol methacrylate (CNMA). Degree of conversion (DC) of the adhesives was assessed by FT-IR. Disk-shaped specimens were prepared for water sorption (WS) and solubility (SL) tests. Human third molars were sectioned to expose medium dentin and restored according to the different adhesives used (n = 5). Then, the specimens were cut into 1 mm2 sticks to evaluate, after 24 h and 6-month aging, microtensile bond strength (µTBS) and nanoleakage by scanning electron microscopy. Data were analysed with ANOVA and Tukey's post-test (α = 0.05). CNMA and PAC completely inhibited all forms of gelatinolytic enzymes. Cardanol achieved a significantly lowest DC, while the other groups did not differ from each other (p > 0.05). PAC achieved significantly higher water sorption, while CNMA solubility was significantly lower when compared to the other adhesives (p < 0.05). PAC provided a statistically higher 24 h and 6-month aging bond strength. Intermediary similar µTBS were presented by control and CNMA (p = 0.108). All adhesives applied attained significantly reduced bond strength after aging (p < 0.05). Interfaces created using CNMA were almost devoid of silver deposits initially, however all groups showed large amounts of silver deposits on resin-dentin interface subjected to water aging. Although CNMA was effective in inhibiting gelatinolytic enzymes, when incorporated into a universal adhesive it could not promote less degradation of the adhesive interface after water aging. Since it is a hydrophobic monomer, CNMA did not interact well with dentin collagen, however it reduced the solubility of the adhesive system besides not interfering in its polymerization. • This work demonstrated, for the first time, the synthesis of a methacrylic collagen crosslinker derived from the cardanol (CNMA). • CNMA showed relevant inhibition of proteolytic enzymes. • The incorporation of 2 wt % of CNMA in a universal adhesive reduced the solubility without interfering in polymerization. • The use of cardanol methacrylic monomers reduced the hydrolytic degradation of simplified dental adhesives. [ABSTRACT FROM AUTHOR]

This study aimed to develop and characterize an ion-releasing experimental fiber-reinforced flowable composite (Bio-SFRC) and dentin treatment solution made of poly(acrylic acid) (PAA) with a high molecular weight. In addition we also evaluated the interface structure and mineralization potential between the Bio-SFRC and dentin. Some mechanical properties (flexural properties and fracture toughness) of Bio-SFRC in comparison with commercial inert (G-aenial Flo X) and ion-releasing materials (ACTIVA-BioActive Base/Liner and Fuji II LC) were assessed (n = 8/group). Calcium-release at different time-points was measured during the first six weeks by using a calcium-ion selective electrode. Surface analysis of composites after being stored in simulated body fluid (SBF) was investigated by using SEM/EDS. Dentin disks (n = 50) were prepared from extracted sound teeth and demineralization was simulated by acid etching. SEM/EDS was used to evaluate the microstructure of dentin on the top surface and at interface with composites after being stored in SBF. Bio-SFRC showed higher fracture toughness (1.6 MPa m1/2) (p < 0.05) compared to Flo X (1.2 MPa m1/2), ACTIVA (1 MPa m1/2) and Fuji II LC (0.8 MPa m1/2). Accumulative calcium release after six weeks from Bio-SFRC (15 mg/l) was higher than other tested ion-releasing materials (≈ 6 mg/l). Mineralization was clearly seen at the interface between treated dentin and Bio-SFRC. None of the commercial tested materials showed signs of mineralization at the interface and dentinal tubules remained open. Significance. Developing such reinforced ion-releasing flowable composite and PAA solution might offer the potential for mineralization at the interface and inside the organic matrix of demineralized dentin. [ABSTRACT FROM AUTHOR]

A new kind of Camellia sinensis -loaded nanocomposite hydrogel based on modified gelatin/iron-metal-organic framework was developed as an antibacterial wound dressing. Gelatin as a biocompatible natural polymer was modified with methacrylate anhydride to produce gelatin methacrylate. Thereafter, acrylic acid and acrylamide were grafted on gelatin methacrylate during an aqueous polymerization process. To enhance the porosity, mechanical strength, and drug loading capability of the hydrogel and reduce its toxicity, iron- based metal-organic framework was incorporated within the hydrogel. To add more functionality to the final wound dressing, Camellia sinensis , an antibacterial herbal drug was loaded on the hydrogel. The structural and chemical properties of prepared nanocomposite hydrogel were investigated by FTIR, XRD, SEM, and TGA techniques. The incorporation of iron-based metal-organic framework within the hydrogel matrix led to an increase in its water absorption value from 400.10 to 547.96 (g/g). The release study of Camellia sinensis (CS) extract from the prepared nanocomposite hydrogel exhibited a sustained release manner. The antibacterial test revealed the nanocomposite hydrogel contain extract has an effective antibacterial function against " Bacillus serous ", " Staphylococcus aureus ", " Streptococcus mutans "," Escherichia coli ", " Klebsiella pneumoniae ", and " Pseudomonas aeruginosa " bacteria. Therefore, the synthesized nanocomposite is a good candidate as an antibacterial hydrogel wound dressing.. [ABSTRACT FROM AUTHOR]

Conductive hydrogels have been extensively studied because of flexibility and skin-like capability to be used as biopotential electrodes for wearable health monitoring. However, they may suffer from poor mechanical properties and stability problems when used in practical applications caused by water evaporation. Herein, we prepared self-adhesive, transparent, flexible and robust ionic gels that can conformal contact with the skin used as biopotential electrodes for precise health monitoring. Cellulose based iogels were prepared by dissolving cellulose using [Bmim]Cl at 100 °C followed by in situ Ultraviolet light photopolymerization of acrylic acid by adding a mixture of acrylic acid and 2-hydroxy-2-methylpropiophenone. Cellulose/polyacrylic acid-based ionic gels-2 (BCELIG-2) has a Young's modulus of 0.2 MPa, a strain at break of 226 %, a modulus of elasticity of 0.1 MPa, and a toughness of 22.5 MJ m−3. Fixing the strain at 40 %, the ionic gels can recover to their original length after ten tensile-unloading cycles. They can accurately detect subtle physical motions such as arterial pulsations, which can provide important cardiovascular information. [Display omitted] [ABSTRACT FROM AUTHOR]

Dumbbell-shaped CoFe 2 O 4 /MoO 2 nanoparticles with a high surface area were synthesized by a wet-chemistry method. The nanoparticle surface was further modified with poly(methacrylic acid) (PMMA) to load doxorubicin (DOX), which was sealed within the composite with a phase change material of 1-tetradecanol (TD). Finally, the CoFe 2 O 4 /MoO 2 /PMMA/DOX/TD composite was prepared. The DOX release was induced by external magnetic/photothermal effects, with CoFe 2 O 4 as the magnetic material and MoO 2 as the photothermal material. The impacts of alternating magnetic field (AMF) frequency and near-infrared (NIR) irradiation power on the thermal effects and DOX release were investigated. Finally, the cytotoxicity of human liver tumor cells (hepatocellular carcinoma) with CoFe 2 O 4 /MoO 2 /PMMA/DOX/TD was studied under different conditions (AMF, NIR, and their combination). The results indicated that AMF/NIR combined thermal effects brought the maximum killing rate of the tumor cells. This research proposed a low-cost synthesis of hybrid thermal materials for AMF/NIR-induced DOX delivery for liver cancer treatment. [ABSTRACT FROM AUTHOR]

Biodegradable shape-memory polymers (SMPs) which are functional materials with applicability for medicine devices are designed to acquire their therapeutically relevant shape and drug release after implantation. In the work, an amphiphilic polymer (PVAD) is synthesized by using polytetrahydrofuran (PTMG), vinyl acetate (VAc), acrylic acid (AA), tetramethyltetravinylcyclotetrasiloxane (D 4 vi) as raw materials. PVAD encapsulating hydrophilic drug as switching phase and poly(l -lactide) (PLLA) as fixing matrix construct an SM system with the characteristic of "reservoir-matrix" drug release. The shape recovery ratio (R r) of medicated PVAD/PLLA reaches 99 % by heat-water stimulation. The effects of release temperature and SM on drug release are investigated. With the release temperature increasing, the medicated PVAD/PLLA accelerates drug release and shows burst release initially, while the drug release for the medicated PLLA changes slightly. The drug release rate goes up after 3 rounds of SM. The mechanism of SM system controlling drug release is put forward based on structural changes. The yield strength and elongation at break of medicated PVAD/PLLA are 29.8 MPa and 44.6 %, respectively. It opens up new perspectives for drug carrier matrices in Pharmaceutical Sciences. [Display omitted] [ABSTRACT FROM AUTHOR]

To date, buccal administration of lipophilic drugs is still a major challenge due to their poor solubility in saliva and limited penetration into mucosal tissues. To overcome these limitations, we developed electrospun patches combining the benefits of mucoadhesive fibers and self-emulsifying drug delivery systems (SEDDS). The fiber system comprises a combination of mucoadhesive thiolated polyacrylic acid fibers and SEDDS-loaded fibers fabricated by parallel electrospinning. The resulting mucoadhesive electrospun SEDDS patches were systemically investigated for fiber characteristics, self-emulsification, mucoadhesion, drug penetration into porcine buccal tissue and biocompatibility. The patches showed high encapsulation efficiency for SEDDS without causing fiber defects or leakage. SEDDS incorporation enhanced the spinning process and reduced the fiber diameter and fiber size distribution. Hydration-dependent self-emulsification provided a controlled release of curcumin being encapsulated in nano-scaled o/w emulsion for over 3 h. Due to the thiolated polyacrylic acid fibers, the buccal residence time of patches was 200-fold prolonged. Further, they promoted a significantly increased drug penetration into buccal tissue compared to fiber patches without SEDDS. Finally, biocompatibility and improved therapeutic effects of curcumin-loaded patches on human keratinocytes and fibroblasts were confirmed. Mucoadhesive electrospun SEDDS patches represent a promising approach to overcome current challenges in the oromucosal delivery of lipophilic drugs to unlock their full therapeutic potential. [Display omitted] • Self-emulsifying drug delivery systems (SEDDS) were electrospun into polymer fibers patches for oromucosal drug delivery. • High loading capacity of the fibers with SEDDS was shown (up to 50% of polymer weight). • 200-fold prolonged buccal patch residence time was achieved by parallel electrospinning of polyacrylic acid thiomer fibers. • SEDDS-loaded fibers ensured prolonged release of curcumin and led to 1200-fold increase in aqueous solubility. • In contrast to conventional fiber patches, SEDDS-loaded mucoadhesive fibers enabled deep mucosal penetration of curcumin. [ABSTRACT FROM AUTHOR]

Locally administered drug delivery systems are promising as they allow to circumvent the side effects associated with systematic administration. In this study, we constructed multifunctional hydrogels by simply mixing commercial alginate (ALG) sols with glucose oxidase (GOx)-conjugated polyacrylic acid-stabilized iron oxide nanoparticles (GPI NPs) and Toll-like receptor 7/8 agonist resiquimod (R848). The injectable sols were able to transform into hydrogels (GPI/R848@ALG) by the ionic cross-linking between ALG and physiological Ca2+ to trap the therapeutic components within the hydrogel framework. Upon intratumoral injection, the hydrogels were employed for starvation therapy, promoted chemodynamic therapy and tumor-associated macrophages (TAMs) repolarization. The energy supply was blocked by consuming the intratumoral glucose via the GOx-catalyzed conversion of glucose into gluconic acid and hydrogen peroxide (H 2 O 2). In vitro results showed that the generated H 2 O 2 could be further converted into highly cytotoxic hydroxyl radicals (·HO) by the Fenton reaction to induce enhanced chemodynamic therapy. The TAMs repolarization studies in vitro exhibited that the GPI/R848@ALG hydrogels up-regulated the expression of CD86 by 63% and down-regulated the proportion of CD206 by 14% with a synergistic effect of the presence of Fe 3 O 4 and R848, suggesting that the multifunctional hydrogels exert functions to direct the remodeling of TAMs from the tumor supportive M2-like phenotype to the tumor destructive M1-like phenotype to further contribute to the antitumor effect. Moreover, both in vitro and in vivo experiments demonstrate that the multifunctional hydrogels exhibit admirable antitumor performance towards 4T1 tumors. This work thereby provides a promising multifunctional nanoplatform for synergistic cancer starvation therapy, chemodynamic therapy and TAMs repolarization. An injectable multifunctional alginate hydrogel loaded with glucose oxidase-conjugated Fe 3 O 4 nanoparticles (GPI NPs) and Toll-like receptor 7/8 agonist (R848) was constructed for starvation therapy, promoted chemodynamic therapy and tumor-associated macrophages (TAMs) repolarization. [Display omitted] [ABSTRACT FROM AUTHOR]

Crude glycerol has become very competitive due to its low price and its use as a platform molecule for the generation of high value-added chemical products. This work proposes a new process to produce acrylic acid from crude glycerol using intensified processes (reactive distillation schemes). An economic analysis was also carried out in relation to the total annual cost to determine the costs associated to each reactive scheme. It was determined that the proposed schemes are economically viable and represent considerable benefits such as the clear reduction in the number of processes equipment. At the same time, it has been determined that these processes can use crude glycerol as raw material to obtain acrylic acid with a purity greater than 90 % in mol. Likewise, the proposed schemes show a significant reduction in energy consumption, up to 74 %, to produce acrylic acid in contrast to previous reported works. [Display omitted] • High value compound from subproduct of biodiesel production. • Process design of acrylic acid production from crude glycerol. • Design and optimization of reactive distillation. • Economic optimization of intensified processes. [ABSTRACT FROM AUTHOR]

Herein, polyamide thin-film composite forward osmosis (TFC-FO) membranes were fabricated using beta-cyclodextrin-graft-poly acrylic acid (ß-CD-g-PAA), as a nature-based graft polymer. The polymer was synthesized by free radical graft polymerization and was consequently incorporated into the active layer to enhance the hydrophilicity, anti-fouling, and overall performance of the conventional TFC-FO membrane. The effect of synthesized polymer concentration on characteristic features such as roughness, morphology, and hydrophilicity of the polymer-modified membranes was thoroughly investigated using different characterization techniques. Apart from that, the separation performance of the newly developed membranes was investigated in FO and reverse osmosis (RO) filtration systems. The transport data revealed increased water flux of around 1.5 times for the membrane which was modified with 1250 ppm of ß-CD-g-PAA solution (TFC-1250) compared to pristine TFC in the FO mode. Interestingly, the mentioned membrane showed demonstrably perm-selectivity of 0.043 bar in RO filtration system. The antifouling investigations of the TFC-1250 membrane against protein and organic foulant in FO mode, not only showed minor fouling tendency, but also revealed great flux recovery ratio (FRR>98%) with a simple washing step. These observations prove the reversible characteristic of fouling in FO process. Hence, this project opens a new way to surface functionalization of TFC membranes with nature-based polymers to render selectivity as well as antifouling features to them. [Display omitted] • A novel natural-based graft polymer was utilized to fabricate novel TFC-FO membrane. • Hydrophile ß-CD-g-PAA polymer led to improved water flux in various filtration systems. • The newly developed membranes were of smooth surface and ultra-thin PA layers. • Superior anti-fouling and reverse fouling feature was observed against protein and organic foulants. [ABSTRACT FROM AUTHOR]

Hydrogel was recognized as one of the most promising materials for adsorption of pharmaceuticals and personal care products (PPCPs). The highly efficient bio-based nanocelluloses fine-tuned poly(acrylic acid) hydrogel (PAA/NC) adsorbent was constructed by adjusting aspect ratio, surface charge and crystallinity of NC. The cross-linked networks were fabricated through a single-step free-radical polymerization via steric effect and hydrogen bonds. The uniform three-dimensional structures with abundant macropores and mesopores were in-situ visualized by the cryogenic-scanning electron microscopy (Cryo-SEM). The diclofenac adsorption capacity of TEMPO oxidized cellulose nanofibers (TCNF) incorporated PAA hydrogel (PAA/TCNF, 559.8 mg·g−1) was circa 2.1 times higher than pristine PAA (293.5 mg·g−1) due to the elevated specific surface area, favorable spatial structure with unimpeded channels and abundant surface-charged carboxylic groups. Moreover, PAA/NC hydrogel exhibited a wide-pH applicability and high salinity tolerance. The adsorption was predominantly determined by hydrogen bonds, validated by XPS and FT-IR analysis. It was demonstrated developed PAA/NC hydrogel with unique porous structure significantly enhanced adsorption capacity for potential application in the purification of refractory organic pollutants-containing wastewater. • NC with varied aspect ratio, surface charge and crystallinity fine-tuned PAA. • PAA/NC hydrogel was prepared by NC induced free-radical polymerization. • The morphologies of PAA/NC hydrogel were in-situ visualization by Cryo-SEM. • The DCF adsorption capacity of PAA was more than doubled by incorporation of TCNF. • PAA/NC hydrogel exhibited wide-pH applicability and high salinity tolerance. [ABSTRACT FROM AUTHOR]

This study revealed a novel metabolic pathway of acrylic acid in Gluconobacter oxydans. First, the intermediate metabolite acrolein was confirmed by HPLC and GC-MS analyses. Then, the enzymes involved were identified based on mRNA expression analysis and gene deletion studies. This novel pathway includes three successive reactions: i) an alcohol dehydrogenase catalyzes 1,3-propanediol to 3-hydroxypropionaldehyde; ii) two isozymes, 3-hydroxyacyl-(ACP) dehydratase and 3-hydroxydecanoyl-(ACP) dehydratase convert 3-hydroxypropionaldehyde to acrolein; iii) an aldehyde dehydrogenase oxidizes acrolein to acrylic acid. An engineered Escherichia coli strain, coexpressing the glycerol dehydratase of Klebsiella pneumoniae and the 3-hydroxyacyl-(ACP) dehydratase of G. oxydans was constructed for acrylic acid production from glycerol. The recombinant strain produced 144.0 ± 9.8 mg/L of acrylic acid in a shake-flask culture. This is the first report demonstrating the biosynthetic pathway of acrylic acid via acrolein, and it provides a new approach for acrylic acid biosynthesis. [Display omitted] • A novel metabolic pathway of acrylic acid (AA) was discovered in G. -oxydans. • Acrolein was identified as the intermediate of AA production from 1,3-porpanediol. • 3-hydroxyacyl-(ACP) dehydratase (3HAD) was verified participate acrolein generation. • Artificial AA synthetic route built with glycerol dehydratase and 3HAD in E. coli. • The recombinant E. coli could produce 144 mg/L AA from glycerol. [ABSTRACT FROM AUTHOR]

Environmental concerns regarding long-time oil spills and oily wastewater discharges have drawn increasingly attention. But up to now, the separation of high-viscosity crude oil-in-water emulsions remains difficult, and the demulsification, aggregation and separation mechanisms of oil-in-water emulsions are still unclear. In this work, a facile strategy is reported to fabricate silica-based superhydrophilic or underwater superoleophobic nanocomposite glass fiber membrane (GFM) via surface grafting method at room temperature. The immobilized epoxy-functionalized SiO 2 nanoparticles improve the roughness and decreased the pore size of GFM. The hydrophilic copolymers of acrylic acid and glycidyl methacrylate (P(AA-co-GMA)) are further grafted on the membrane to increase its hydrophilicity, thereby achieving durable and efficient separation of crude oil-in-water emulsion with a separation efficiency of 96.2 ± 0.4% and a flux of 4725 ± 62 L·m−2·h−1. Moreover, by an in-situ observation of oil droplets on the membrane fiber surface, the demulsification of oil-water emulsions and the coalescence of small oil droplets are discovered when the oil-in-water emulsions flowed through the superhydrophilic fiber surface. Owing to the great demulsification capability, the as-prepared nanocomposite GFM is endowed with excellent crude oil-in-water emulsion separation performances. [Display omitted] • Silica-based nanocomposite membrane for crude oil/water separation was fabricated. • The membrane exhibits underwater superoleophobicity and high separation efficiency. • The coalescence of oil droplets on the membrane fiber surface was observed in-situ. • The membrane shows great self-cleaning and ultralow crude oil-adhesion properties. [ABSTRACT FROM AUTHOR]

• Hydroxyapatite/chitosan (HA/Cs) nanocomposites electrodeposited on Ti metal. • Acrylic or acetic acids as cs solvents led to morphology changes of HA/Cs coating. • HA/Cs coated samples exhibited enhanced corrosion resistance compared to uncoated Ti. • The highest corrosion resistance was achieved in presence of acrylic acid (6 %). Titanium (Ti) and its alloys are widely used in bone defect repair owing to their advantages, including high strength, corrosion resistance, and biocompatibility. The formation of a stable oxide layer on Ti implants enhances the osseointegration process. Nevertheless, additional progress is required to improve the incorporation of these implants at the microscopic and nanoscopic levels to achieve a biocompatible interface. The main objective of this study was to enhance the morphology of hydroxyapatite and the corrosion resistance of Ti implants by applying hydroxyapatite/chitosan (HA/Cs) nanocomposite coatings embedded with carboxylic acids. The coatings were fabricated by electrodeposition, wherein various acid concentrations (acrylic and acetic acids) were employed as Cs electrolyte solvents to enhance the adhesion and bond strength with the titanium metal substrate. The microstructures of the HA/Cs coatings were analyzed using X-ray diffraction. The results demonstrated that the structure of HA was affected by the type of acid used and its concentration as the crystallinity increased with a high concentration of acrylic acid. Additionally, the morphology of HA/Cs was analyzed using a transmission electron microscope. The results showed that the morphology of HA/Cs changed from a hexagonal rod-like shape with acrylic acid samples into a needle-like shape in acetic acid samples. The corrosion behavior was investigated using electrochemical impedance spectroscopy (EIS) in a simulated body fluid (SBF) at 37±2ºC. The EIS results showed a high corrosion resistance with phase angles close to −80° and high impedance values of 80.5 kΩ cm2 with a high concentration of acrylic acid. These results indicated the formation of a highly adhesive and stable film on the implants in the test solution. In conclusion, based on this study and our previous work, the corrosion resistance, good biocompatibility, and biomineralization properties of the prepared HA/Cs-coated Ti recommend it as an alternative implant for clinical applications. [ABSTRACT FROM AUTHOR]

Combining natural polysaccharides with synthetic materials improves their functional properties which are essential for designing sustained-release drug delivery systems. In this context, the Aloe vera leaf mucilage/hydrogel (ALH) was reacted with acrylic acid (AA) to synthesize a copolymerized hydrogel, i.e., ALH-grafted-Polyacrylic acid (ALH-g-PAA) through free radical copolymerization. Concentrations of the crosslinker N,N′ -methylene-bis-acrylamide (MBA), and the initiator potassium persulfate (KPS) were optimized to study their effects on ALH-g-PAA swelling. The FTIR and solid-state NMR (CP/MAS 13C NMR) spectra witnessed the formation of ALH-g-PAA. Scanning electron microscopy (SEM) analysis revealed superporous nature of ALH-g-PAA. The gel fraction (%) of ALH-g-PAA was directly related to the concentrations of AA and MBA whereas the sol fraction was inversely related to the concentrations of AA and MBA. The porosity (%) of ALH-g-PAA directly depends on the concentration of AA and MBA. The ALH-g-PAA swelled admirably at pH 7.4 and insignificantly at pH 1.2. The ALH-g-PAA offered on/off switching properties at pH 7.4/1.2. The metoprolol tartrate was loaded on different formulations of ALH-g-PAA. The ALH-g-PAA showed pH, time, and swelling-dependent release of metoprolol tartrate (MT) for 24 h following the first-order kinetic and Korsmeyer-Peppas model. Haemocompatibility studies ascertained the non-thrombogenic and non-hemolytic behavior of ALH-g-PAA. [Display omitted] • Synthesis of Aloe vera mucilage-based hydrogel by free radical polymerization • Copolymeric hydrogel appears a superporous and stimuli-responsive material • Hydrogel exhibits on-off switching at pH 7.4 and 1.2, respectively • The synthesized hydrogel shows pH-dependent swelling and drug release • Hydrogel exhibited non-hemolytic and non-thrombogenic potential [ABSTRACT FROM AUTHOR]

The severe negative effects of impurities adhering to the external surface of wearable devices can significantly influence the signal transmission, performance, and lifespan of hydrogel sensors. Herein, we developed an ion-conducting hydrogel sensor with a strong adhesive side and a non-adhesive side, similar to a "semi-releasing material." This hydrogel, formulated using deep eutectic solvents obtained from choline chloride and acrylic acid, contained lignin. This versatile material, exhibiting properties similar to semi-releasing materials, was treated with an AlCl 3 solution on one side. Additionally, the hydrogel was successfully used as a highly adhesive strain sensor for real-time monitoring of various human activity signals. Moreover, the hydrogel demonstrated excellent environmental tolerance and conductivity. Lignin extracted from wood flour endowed the hydrogel sensor with excellent adhesion energy (up to 427.1 J/m2) and UV resistance. Treatment of hydrogels with AlCl 3 completely eliminated their adhesiveness, thereby enhancing fracture elongation and tensile strength. This improvement can be attributed to the absence of carboxyl groups and the formation of a metal-phenolic network. The implementation of this convenient and efficient strategy provides a more feasible approach to address challenges related to impurity adhesion and signal transmission in flexible wearable devices. [Display omitted] [ABSTRACT FROM AUTHOR]