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In the present study, solvent-based acrylic copolymers were successfully synthesized by solution polymerization using methyl allyl polyethylene glycols ether, acrylic acid, and 2-ethyl hexyl acrylate for the fabrication of high-performance pressure-sensitive adhesive tapes. Different techniques (NMR, FTIR, TGA/DTG, Contact Angles, PSAs Test) were used to characterize the physical and thermal properties of the copolymers. The obtained copolymers were investigated as a possible adhesive for permanent or removable applications such as security labels for power equipment, foil tape for HVAC ductwork, automotive interior trim assembly, and sound/vibration dampening films. When the contact angles of the synthesized copolymers were examined, it was observed that while the amount of acrylic acid in the copolymer content was constant, the contact angle increased with the increase in the percentage of HPEG. In addition, while the amount of HPEG was constant in the copolymers, it was observed that the contact angle decreased with the increase in the percentage of acrylic acid. As a result, it was determined that the obtained copolymers showed hydrophilic character and wetted the contact surface. When the thermal properties of the copolymers were examined, while the acrylic acid ratio was constant, the thermal stability increased with increasing HPEG amount. While the HPEG ratio is constant in the copolymer content, the decrease in thermal stability with increasing acrylic acid is thought to be due to decarboxylation. Also, 7% reduction in DTG curves is evidence of decarboxylation of copolymers. According to the results of the pressure-sensitive adhesive test, it was observed that the surface wetting degree of the copolymers changed in direct proportion to the amount of acrylic acid increased and inversely proportional to the amount of HPEG, and the potential of the adhesives obtained in addition to being high-performance pressure sensitive adhesive tapes.

To address the rising challenges in self-controlled tandem processes, a catalytic reactor with two reversely-responsive layers was fabricated, for which the two layers acted as the carriers of two different-type active sites so as to achieve the adjustable catalytic ability. This first layer was a shape-memory copolymer consisting of 2-acrylamido-2-methylpropane sulfonic acid and 1-heptene. Given the “frozen” domains in the copolymer at low temperatures, the channel of the substrate became closed. At middle temperatures, the channel of the substrate became open as a result of the activation of the copolymer. The second layer was a copolymer embedding Ag nanoparticles made of polymeric 2-(trifluoromethyl) acrylic acid and 2-vinylpyridine. This layer showed the “closed” channel at low temperatures due to the electrostatic interactions between the two polymeric components, which inhibited the entry of reactants. At higher temperatures, as the polymeric interactions at this layer were broken, the channel in this layer became open for the reactants. In combination with the contained acidic sites and catalytic Ag nanoparticles sites in the two layers, which were individually responsible for catalytic hydrolysis and reduction, the reactor did not show substantive catalytic ability at low temperatures due to the closed channels in both the two layers. At middle temperatures, the reactor ran with simple hydrolysis due to the open channel in the first layer which contained acidic sites. At higher temperatures, the reactor ran with tandem catalytic processes because of the open channels in the two layers. Hence, the design of the dual-responsive catalytic reactor acquired the non-tandem/tandem self-controlled catalytic ability.

A superabsorbent hydrogel (SAH) composite from starch and polyacrylic acid p(St/AAc) was prepared by free radical polymerization in the presence of potassium persulfate initiator. The effects of two polymer composition on gel fraction, swelling, and water retention have been investigated. It was found that swelling was extremely sensitive to the acrylic acid contents; it increased with the decrease of acrylic acid content. Moreover, the hydrogel samples showed an excellent water retention capability. The swelling kinetics and water diffusion mechanism in distilled water were also discussed in order to choose appropriate SAH functioning as soil conditioner of sunflower under drought stress. A pot experiment was carried out to study the ameliorative role of SAH application on sunflower (Helianthus annuus L. Var Sakha) plants grown under drought stress. Growth parameters, content of photosynthetic pigments, total proline and phenol, and antioxidant enzymes were determined. The shoot and root length increased up to 49.84% and 5.35% rather than in the absence of SAH. Growth parameters and photosynthetic pigments of sunflower plants grown under drought in the absence of SAH were reduced. Hydrogel application enriched the photosynthetic pigment. Besides, it also decreased the harmful impacts of drought on sunflower plants. The results herein demonstrated that the hydrogel decreased the proline, total phenols, catalase, peroxidase, and polyphenol oxidase content. The findings of this study indicate that the use of hydrogel can be considered as an unconventional and novel tool in the mitigation of drought stress.

Ionic liquid (IL)-decorated copolymers based on poly((ethylene glycol) methyl ether methacrylate)-co-(acrylic acid)-co-(1-vinyl-3-ethylimidazolium hexafluorophosphate) were prepared and used as bin...

The ligation behavior of the chalcone ligand namely (E)-3-(4-hydroxy-3-methoxyphenyl) acrylic acid (ferulic acid) (FA) toward the Cu(II) and Zn(II) ions was determined. The structure of the isolated solid complexes was elucidated by elemental analyses, spectral techniques (IR, UV–Vis, 13C– and 1H-NMR spectra) as well as the conductance measurements and thermal analyses. UV–Vis spectra and magnetic moments had suggested square planar and tetrahedral stereochemistry for Cu(II) and Zn(II) complexes, respectively. The kinetic and thermodynamic parameters for some selected decomposition steps have been calculated. Two precise and sensitive spectrophotometric methods were utilized to determine Zn(II) and Cu(II) complexes with ferulic acid using a micellar media of cetylpyridinium bromide (CPB) and sodium lauryl sulfate (SLS) with an absorption maxima of 430 and 465 nm for Zn(II) and Cu(II), respectively. Various analytical conditions, for example, the concentration of the reagent, temperature, the sequence and timing of addition were also looked into. Under optimum conditions, the complexes exhibited good linearity in concentration range of 2.0–70.0 and 4.0–140.0 µg mL−1; molar absorptivities 1.3161 × 104 and 8.826 × 103 L mol−1 cm−1; and Sandell’s sensitivity 0.00496 and 0.00719 µg cm−2 for the proposed methods of Zn(II) and Cu(II), respectively. The complexes ratio was found to be 1:2 [Zn(II):FA or Cu(II):FA] and the stability constants were 2.771 × 105 and 2.826 × 105, respectively. Finally, the newly synthesized complexes were shown potent antimicrobial activity.

The fast development of Pickering emulsion systems inspires burgeoning demand on the universal synthesis platform for the surface modification of solid particle emulsifiers. In this work, a mild and convenient “visible light–mediated surface grafting through (VSGT)” strategy is proposed. Through the two-step strategy, silica nanoparticles (SNPs) were firstly modified by vinyl alkoxysilane and then used as the substrate for grafting homopolymer brushes via reversible addition-fragmentation chain transfer polymerization under the irradiation of a compact fluorescent lamp (CFL) light source. The whole process was proceeded at room temperature without tedious conditions and complex operations. Importantly, simply by changing the monomer types, hydrophilic acrylic polymer chains can all be grafted on SNP with controlled chain length and relatively uniform high surface densities including poly(acrylic acid) (PAA), poly(N,N-dimethylacrylamide) (PDMA), poly(N-isopropylacrylamide) (PNIPAM), and poly(diacetone acrylamide) (PDAAM). Through the synthesis platform, the interfacial performance of the surface-grafted nanoparticles exhibited as amendable working as Pickering emulsifiers in oil–water system, illustrated by the evolution of interfacial tensions and the inner structures of the corresponding Pickering emulsions. Moreover, the emulsion stabilized by SNP-g-PAA and SNP-g-PNIPAM showed pH and temperature triggered emulsification-demulsification behaviors, respectively, convincing the contribution of the surface grafted polymers and provide a feasible clue for the subtle design on the interfacial texture in advanced Pickering emulsions.

Based on the abundant and low-cost zinc-based acrylate resins, C/ZnO composites were fabricated via one-step carbonization at 700 °C in a N2 atmosphere for 2 h. Zinc-based acrylate resins, which were synthesized by free-radical polymerization of butyl acrylate (BA), acrylic acid (AA) and vinyl acetate (VAc) and dehydration condensation of Zn(OH)2, provided a common source for carbon and ZnO. These materials demonstrate enhanced electromagnetic wave absorption (EMWA) behavior with tunable microwave absorption bands at 2–18 GHz, which is related to the molar ratio (mol%) of Zn(OH)2 to acrylate monomers in zinc-based acrylate resins. Remarkably, the 0.11 mol% C/ZnO composite exhibits outstanding absorption properties: the minimum reflection loss (RLmin) at 16.7 wt% loading of −34.66 dB is observed at 3.0 mm and 10.32 GHz, and an RLmin of −24.83 dB is observed at a small thickness of 1.5 mm with an effective absorption bandwidth (EAB) of 3.61 GHz. Moreover, the EAB (RL ≤ −10 dB) from the C band to Ku band is achieved by simply adjusting the thickness of the absorbers, which are superior to the other hybrids of organic carbon and ZnO. These results provide a new strategy for the preparation of carbon-based composites containing metal oxides and their application in high-performance microwave absorption.

Soft-tissue replacements are challenging due to the stringent compliance requirements for the implanted materials in terms of biocompatibility, durability, high wear resistance, low friction, and water content. Acrylate hydrogels are worth considering as soft tissue implants as they can be photocurable and sustain customized shapes through 3D bioprinting. However, acrylate-based hydrogels present weak mechanical properties and significant dimensional changes when immersed in liquids. To address these obstacles, we fabricated double network (DN) hydrogels composed of polyacrylic acid (PAA) and bacterial cellulose nanofibers (BCNFs) by one fast UV photopolymerization step. BCNFs/PAA hydrogels with a 0.5 wt% BCNFs content present an increased stiffness and a lower, non-pH-dependent swelling than PAA hydrogels or PAA hydrogels with cellulose nanocrystals. Besides, BCNFs/PAA hydrogels are biocompatible and can be frozen/thawed. Those characteristics endorse these hybrid hydrogels as potential candidates for vascular and cartilage tissue implants., This research was supported by the Spanish Ministry of Science and Innovation through the RTI2018-096273-B-I00 and PID2021-122645OB-100 projects, the ‘Severo Ochoa’ Programme for Center of Excellence in R&D (CEX2019-000917), the Generalitat de Catalunya (2017SGR765 grant), and partially by the Ministry of Science Technology and Space of Israel (3-15638). N.M. acknowledges the Ph.D. scholarship (PRE2019-089754) in the framework of the Biotechnology Ph.D. program of the UAB. S.R-S., N.M., A.L. and A.R. participate in the Spanish National Research Council (CSIC) interdisciplinary platform for sustainable plastics toward a circular economy (SusPlast) and in the Aerogels COST ACTION (CA 18125), EPNOE network and Red Nanocare RED2018-102469-T. Finally, the authors want to express their gratitude for the technical services of ICMAB and ICN2 (electron microscopy)., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).

In this study, a quad acrylic copolymer composed of four monomers namely acrylic acid, methacrylic acid, butyl acrylate, and methyl methacrylate/cloisite30B(C30B) nanocomposites with different load...

The volume change and shuttle effect of sulfur are detrimental to the stability and electrochemical performance of the sulfur cathode in lithium–sulfur (Li–S) batteries. In this study, a triple cro...

Herein, poly (acrylic acid) (PAA) microgels were synthesized via alcohol type cross-linked by a free radical precipitation polymerization approach. At the first time, 1,6-hexanediol (1–6 diol), trimethylolpropane (TMP), and pentaerythritol (PEN) were selected as multifunctional cross- linking agent to synthesize cross-linked poly(acrylic acid) microgels. Alcohol type cross-linking agents can connect the PAA chains. The cross-linking reaction takes place due to reaction between hydroxyl groups of various cross-linkers and carboxyl groups of PAA chains. All of the hydroxyl groups do not participate in the reaction with acid groups of polymer chains through the polymerization stage; therefore, unreacted hydroxyl groups will react through sample drying (post-curing stage). The influence of cross-linker functionality and its concentration on various properties like swelling capacity, gel content, Tg (glass transition temperature), and rheological behavior were examined. The PAA microgels prepared via this cross-linking approach were compared to properties of microgels synthesized by epoxy type and vinyl type cross-linking agents in the previous studies. As a result, synthesized microgels via novel mechanisms have higher properties (for example, rheological and thermal properties) than that of PAA microgels prepared via the conventional mechanism. These behaviors can be due to decreasing $$\overline{Mc}$$ (average molecular weight of two successive cross-links) in the polymeric network by utilizing new cross-linkers.

For the improvement of poly (N-isopropylacrylamide) properties, new series of poly (N-isopropylacrylamide-Co-acrylic acid-Co-vanillin acrylate) terpolymer was fabricated with molar concentrations 5, 10, and 15 mol% of acrylic acid (AA) with 10 mol% of vanillin acrylate (VA). Monomer and polymers were chemically evaluated using (1H NMR, 13C, FT-IR, and UV); all structures emphasized logical results. The post-polymerization has been done for terpolymer with tryptophan and threonine; they were chemically investigated. Polymers and post-polymers have been physically characterized using SEM, X-ray, DSC, TGA, and SEM. Lower critical solution temperature was measured using turbidity by UV–VIS spectroscopy and by micro-DSC. These polymers will be used in the post-polymerization of many biomolecules for biomedical applications

In this research, the MgO nanoparticles were incorporated into (acrylic acid /polyvinyl alcohol) PAA/PVA hydrogel by using gamma radiation technique at a dose rate of 1.9 kGy/k. The unique properties of MgO nanoparticles as structure, active surface properties, and stability make such nanoparticles have considerable potential as antimicrobial agents in food applications. In spite of known antibacterial activity of MgO NPs, the mechanism of metal oxide nanoparticle action on bacteria is complicated and not fully understood. The PAA/PVA system was mixed with various contents of MgO nanoparticles to prepare its MgO nanocomposite hydrogels. The morphology of the PAA/PVA copolymer hydrogels and their MgO nanocomposites hydrogels was characterized by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to prove the surface, bulk change, size, and the formation of MgO nanoparticles. TEM measurement estimated that the average particle size of prepared MgO NPs was 7.13 nm. The swelling properties of the various AAc hydrogels and its MgO nanocomposites hydrogels were also studied. The prepared acrylic acid copolymers and their MgO nanocomposites were examined for applicability as antibacterial material, and the results revealed that hydrogels and MgO nanocomposites hydrogels prepared in this study have higher antibacterial activity toward Staphylococus Aureus (S.a.) than Escherichia Coli (E. Coli). The discovery of novel and efficient nanocomposites may have a potential therapeutic role.

Loading and release behavior of a cationic dye, namely, safranine-T, through layer-by-layer (LbL) multilayered films of poly(diallyldimethylammonium chloride) (PDADMAC) and single/blend anionic polyelectrolytes (PEs), namely, poly(acrylic acid) (PAA), and poly(styrenesulfonate) (PSS), are described. The growths of PDADMAC/PSS-PAA multilayers and their safranine-T sorption behavior are monitored using the UV-Vis technique and discussed in terms of blend composition of anionic PEs and pH as well as their hydrophilicity and topography. The dye loading and desorption properties of the LbL films prepared from single/blend negatively charged PEs mainly depend on the interactions of PEs and safranine T. Strong interactions between PSS and safranine T result in a higher dye entrapping inside LbL films whereas either PAA-rich or single PAA-based LbL film exhibits larger dye desorption. A higher PSS content in the feed blend composition leads to an observable increase in theta(ave) and surface roughness whereas the use of PAA can yield a flatter surface due to its partially recomposed chain conformational structure at pH 11. Consequently, LbL multilayers obtained from single and blend polyanions can be considered as an encouraging material platform for the controlled release of charged species such as protein, drug, and dye. because of their tunable physicochemical and morphological properties as well as surface wettability.

Interaction of the anionic copolymer of acrylic acid and acrylamide with a molar ratio of monomer units of 75 : 25 and poly(N,N′-diallyl-N,N′-dimethylammonium chloride) in aqueous solution is studied. The interaction is accompanied by the formation of a polycomplex stabilized by multiple salt bonds between oppositely charged groups of both polyelectrolytes. A nonstoichiometric polycomplex with a tenfold excess of anionic groups is present in solution in the form of particles with a diameter of about 300 nm; the particles retain their aggregate stability for 30 days. The application of aqueous solutions of individual polymers and the nonstoichiometric polycomplex on the surface of sand with a particle size of 0.15 ± 0.05 mm is associated with the formation of composite polymer-sand coatings. The highest mechanical strength is possessed by coatings with the participation of an anionic copolymer and a polycomplex. For sand and polycomplex coatings, the weight loss during water treatment is 10%, which is lower than that in the case of traditional polyacrylamide soil stabilizer. The polycomplex at a concentration of up to 0.33 wt % does not exhibit toxicity to microorganisms, thereby indicating that the use of a negatively charged polycomplex is promising for obtaining waterproof protective coatings on the surface of sandy soils.

Chitosan graft poly(acrylic acid)/graphite oxide/attapulgite (CTS-g-PAA/GO/APT) composite hydrogel has been synthesized and used to remove rhodamine B (RB) and methyl orange (MO) from aqueous solutions through adsorption. The composite is characterized by infrared spectroscopy (IR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The influence of adsorption conditions, i.e., the content of graphite oxide (GO) and attapulgite (ATP), the initial concentration of dye solutions, the adsorption time, ionic strength, pH values and dosage of the composite, on the adsorption capacities has been studied in detail. It is found that small amount of GO and ATP can improve the adsorption capacities of dyes significantly. Adsorption capacities of RB and MO onto CTS-g-PAA graft copolymer are 36.7 and 56.4 mg/g, respectively, while those onto CTS-g-PAA/GO/APT (GO 0.02 g, APT 0.05 g) composite hydrogel are 92.6 and 186.5 mg/g, respectively. Adsorption isotherms and thermodynamics are discussed. It indicates that the adsorption of RB is in accordance with both the Langmuir and R-P isotherm equations. However, that of MO meets the R-P equation. The adsorption of RB is spontaneous, while that of MO is not. Kinetic studies show that the adsorption of both RB and MO is in accordance with the Lagergren pseudo first-order kinetic model.

Grafting by pre-irradiation technique is rarely reported in recent literature. In this respect, natural rubber latex (NRL) films and its blends with potato starch (NRL/P.St) were prepared at various compositions using solution casting technique. Pre-irradiated NRL films with gamma radiation at doses from 30 to 100 kGy were grafted with hydrophilic monomers namely, acrylic acid (AAc) and acrylamide (AAm) to enhance NRL hydrophilicity. The grafted films of NRL and NRL/P.St blends were structurally and morphologically characterized by different techniques including FTIR spectroscopy and scanning electron microscopy (SEM). Hydrophilicity properties of grafted films were studied intensively through evaluating water absorption percentage of the grafted films. The water absorption study concluded that NRL and NRL/P.St blend films grafted with acrylamide have higher water affinity than those grafted with acrylic acid monomer. Enhancing the hydrophilicity of NRL and NRL/P.St blend films make it possible to study the biodegradability of the prepared films. Studying the effect of incubation time in soil on the weight loss of samples showed that the biodegradability of NRL-g-AAm and NRL/P.St (70/30)-g-AAm is higher than their counterparts grafted with AAc. The results showed that the microbial activity inside the specimens in the case of grafted NRL films with AAm monomer was accelerated in the first 10 days in soil burial test. Calculation of the weight loss and digital photographs of the films showed significant differences after 90 days of incubation in soil and the films grafted with AAm have higher weight loss than those grafted with AAc.

In this study, Acrylic acid (AA), acrylamide (AM), and 16,16-dimethylheptadecan-1-amine (PJM-T) were copolymerized using gamma irradiation with 60Co γ-rays at a dose of 25 KGy to form a novel composite; Poly(acrylic acid-co-acrylamide/16,16-dimethylheptadecan-1-amine P(AA-co-AM/PJM-T). P(AA-co-AM/PJM-T) is characterized by different physicochemical techniques and used as a sorbent for rare earth elements from monazite. The optimum pH for the sorption process at 25 ℃ is 4.5 and the equilibrium attained at 60 min. Different kinetics and isothermal models is applied. The maximum adsorption capacity is 182.15 ± 3.73 mg g−1 at 25 ℃. The sorption reaction regulates a pseudo 2nd order mechanism and the process is spontaneous.

The aim of the current research work was to fabricate polymeric nexus for controlled delivery of metoprolol tartrate by using free radical polymerization. Polymer (aloe vera, sodium carboxymethyl cellulose, and meggletose) was crosslinked with monomer (acrylic acid) by using N,N methylene bisacrylamide. Swelling behavior was studied in pH 1.2 and 7.4. Sol gel fraction depicted gel fraction increased with the increase in feed ratio (polymer, monomer, and crosslinker). Optimized formulation was evaluated via Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). FTIR confirmed compatibility of metoprolol with formulated system. Moreover, pH-dependent swelling was observed, experiencing significant swelling at higher pH. SEM depicted porous architecture which is responsible for swelling, drug loading, and release. Dissolution studies showed percentage drug release was significant in pH 7.4. Hence, the current research work demonstrates sustained delivery of metoprolol by employing varying concentration of polymer, monomer, and crosslinker. These fascinating properties made hydrogel a promising carrier for sustained drug delivery.

This study focuses on the synthesis of poly(e-caprolactone) diacrylate (PCLDA) for the fabrication of micelle-cross-linked sodium AMPS wound dressing hydrogels. The novel synthetic approach of PCLDA is functionalizing a PCL diol with acrylic acid. The influences of varying the PCL diol/AA molar ratio and temperature on the suitable conditions for the synthesis of PCLDA are discussed. The hydrogel was synthesized through micellar copolymerization of sodium 2-acrylamido-2-methylpropane sulfonate (Na-AMPS) as a basic monomer and PCLDA as a hydrophobic association monomer. In this study, an attempt was made to develop new hydrogel wound dressings meant for the release of antibacterial drugs (ciprofloxacin and silver sulfadiazine). The chemical structures, morphology, porosity, and water interaction of the hydrogels were characterized. The hydrogels' swelling ratio and water vapor transmission rate (WVTR) showed a high swelling capacity (4688-10753%) and good WVTR (approximately 2000 g·m-2·day-1), which can be controlled through variation of the PCLDA concentration. The mechanical property results confirmed that PCLDA improved the mechanical properties of the hydrogel; the stress increased from 37 to 68 kPa, and the strain increased from 198 to 360% with increasing PCLDA (0-30% wt of Na-AMPS). These hydrogels presented no cytotoxicity based on over 70% cell viability responses (L929 fibroblasts) using an in vitro 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Additionally, the drug release mechanism, kinetic models, and antibacterial activity were determined. The results demonstrated that antibiotics were released from the hydrogel with a Fickian diffusion mechanism and antibacterial activity against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus). Based on the results obtained, and bearing in mind that further progress still needs to be made, the fabricated hydrogels show considerable potential for meeting the stringent property requirements of hydrogel wound dressings.

A series of fluorinated polyacrylate emulsion pressure-sensitive adhesives (PSA) with various lengths fluorinated side chains were synthesized by using n-butyl acrylate (nBA), acrylic acid (AA), 2-...

A set of novel biocompatible aliphatic-aromatic nanocomposites, including numerous acrylic acid-grafted poly(butylene carbonate-co-terephthalate) (g-PBCT) and organically-modified layered zinc phenylphosphonate (m-PPZn), were successfully synthesized via polycondensation and transesterification. A primary covalent linkage was produced between the biocompatible polymer and the inorganic reinforcements. Fourier transform infrared spectroscopy and 13C-nuclear magnetic resonance spectra demonstrated the successful grafting of acrylic acid into the PBCT (g-PBCT). Both wide-angle X-ray diffraction data and X-ray photoelectron spectroscopy analysis showed that the g-PBCT polymer matrix was intercalated into the interlayer spacing of the m-PPZn and was chemically interacted with the m-PPZn. The addition of m-PPZn in the g-PBCT matrix significantly improved its storage modulus. A slight increase in thermal stability was observed in all the g-PBCT/m-PPZn composites. Both results are attributed to the presence of covalent bond between g-PBCT and m-PPZn.

© 2021, Institute of Chemistry, Slovak Academy of Sciences.In this study, firstly, a new phthalonitrile derivative was synthesized from the reaction of caffeic acid with phthalonitrile. Then, metal phthalocyanine complexes were obtained from the reaction of this phthalonitrile derivative with metal salts. Compounds were characterized by UV, NMR, IR and Mass spectroscopy methods. In addition, the fluorescence and electronic properties of the diamagnetic zinc phthalocyanine compound were investigated. The performances of dye-sensitized solar cells of compounds were examined. The calculated power conversion efficiencies (η %) of the complexes using the obtained current density (J)-voltage (V) curves were determined that these compounds can be used as promising sensitizers in solar cell applications. The calculated power conversion efficiencies (% η) of the complexes were found to be at a reasonable level. Molecular orbital properties such as HOMO–LUMO energy gap, Fermi Energies, state density spectrum, and molecular electrostatic potential surfaces were calculated for each phthalocyanine molecule. In addition, the amount of phthalocyanine required for ideal dye sensitivity was investigated.

A novel pH-responsive magnetic nanosystem was designed and developed for cancer therapy. For this purpose, a well-defined terpolymer was synthesized through the polymerization of 2-hydroxyethyl methacrylate (HEMA) monomer using reversible addition fragmentation chain transfer (RAFT) technique and simultaneous grafting of e-caprolactone (e-CL) monomer via ring-opening polymerization (ROP) approach followed by block copolymerization of acrylic acid (AA) monomer via RAFT polymerization method, in order to produce a poly(acrylic acid)-block-[poly(2-oxyethyl methacrylate)-grafted-poly(e-caprolactone)] [PAA-b-(POEMA-g-PCL)]. Afterward, magnetite nanoparticles (Fe3O4 NPs) were synthesized through chemical co-precipitation method, and then incorporated into the developed terpolymer through physical interactions (e.g., electrostatic and hydrogen bonding) via solution mixing approach. The doxorubicin hydrochloride (Dox), as an anticancer model drug, loading (LE) and encapsulation (EE) efficiencies of the fabricated magnetic nanosystem were calculated to be 96 ± 5 and 9.65 ± 0.5%, respectively. The drug release study results revealed that the developed drug delivery system (DDS) could be efficiently control the delivery of Dox in response to pH stimuli.

Hydrogels were produced from mixtures of polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), and acrylic acid (AAc) using γ-radiation at doses of 3, 7, and 10 kGy and the effect of the variation in concentration of AAc within 0%–3% (w/v) on the gelation, swelling, crosslinking, thermal properties, crystallinity, mechanical properties, and surface morphology of the hydrogels were characterized and their adsorptive removal properties for methylene blue (MB) was investigated. The swelling trend was pH-dependent which was dictated by the dominance of two competing factors namely, crosslink density and hydrophilicity. Although thermal analysis showed that the presence of AAc decreased the thermal stability of the hydrogels, SEM images exhibited gradual morphological changes establishing the role of AAc as a crosslinker, and thus increasing the elastic moduli, toughness, and crystallinity of the hydrogels. However, correlation between the characterization results revealed that, in spite of AAc occupying some of the crosslinking sites within PVA–PVP networks, at low concentration (1% w/v), it could not polymerize enough to contribute to the crosslinks. FTIR spectral analysis revealed a possible gelation mechanism along with the points of interaction among the gel-components. MB adsorption capacity of the hydrogels reached a maximum of 117 mg/g following pseudo-second-order kinetics through film diffusion mechanism while the adsorption isotherm resembled most with that of Langmuir.

Poly(acrylic acid) and poly(2-(dimethylamino)ethyl acrylate) chains were grafted to polyurethane (PU) using the graft-polymerization method in order to enhance the water compatibility of PU. The grafted chains were ionized into cationic or anionic form depending on the addition of strong acid or base. The grafted polymer chains did not affect the melting, crystallization, and glass transition of the soft segment of PU due to the softness of the chain. The cross-link density and solution viscosity increased due to the linking between the grafted chains, but the slight cross-linking did not disturb the solvation of PU. The slight cross-linking notably enhanced the maximum tensile stress and shape recovery capability, and the water compatibility of PU could be notably enhanced by the grafted ionized chains. Overall, the grafting of ionized polymeric chains onto PU could enhance the hydrophilicity of PU surface, tensile strength, and shape recovery capability.

The objective of the present study was to improve the mucosal adherence of nasal formulations through the application of swellable, microporous drug containing crosslinked hydrogels. Halloysite nanotubes (HNTs) alone, poly acrylic acid/poly-vinyl-alcohol (PAA/PVA) hydrogels and poly acrylic acid/poly-vinyl-alcohol)/Halloysite nanotubes (PAA/PVA/HNTs) hydrogels were prepared by free-radical polymerization. N–N methylene bisacrylamide (MBA) and ammonium per-sulfate (APS) were used as cross-linker and initiator, respectively. Studies of Diffusion coefficient, swelling, porosity, loading and drug release at various pH medium, mucoadhesive strength and impact on Caco-2 cell viability were conducted. The drug, HNTs and hydrogels were evaluated by FTIR, SEM and XRD. An increase in gel fraction, porosity and drug loading capacity of PAA/PVA/HNTs was observed compare to PAA/PVA hydrogels, which may be due to increased available surface area. The drug loading capacity showed a direct relationship with the HNTs concentration of 25 to 75% in the PAA/PVA/HNTs hydrogels. The presence of carboxylic acid, hydroxyl, aluminum, silicate groups was observed in the FTIR spectrum. The SEM showed a uniform structure of the PAA/PVA hydrogels but became a encrusted like structure in the PAA/PVA/HNTs hydrogels. The PAH2 formulation showed a mucoadhesive strength more than 80% and the cell viability studies did not reveal a significant difference between the control and dispersion of HNTs and PAA/PVA, PAA/PVA/HNTs.

The objective of current study was to fabricate PEG based hydrogels cross linked with monomer i.e. acrylic acid and 2, Acrylamide-2-methyl propane sulfonic acid (AMPS) in aqueous media. N,N'-Methylenebisacrylamide (MBA) was used as cross linker while ammonium per sulfate was added in reaction as initiator. Sodium bicarbonate was used as to create pores in hydrogel making the formulations superporous. Ivabradine hydrochloride as model drug was loaded into prepared hydrogel formulation. FTIR confirmed the compatibility of Polyethylene glycol with acrylic acid and AMPS. Thermal stability of PEG based hydrogels was confirmed by DSC and TGA techniques. Prepared hydrogels showed pH dependent swelling behavior. Presence of AMPS caused excellent swelling of hydrogels due to its polyelectrolyte nature while in case of acrylic acid dense cross linking cause comparatively less swelling of acrylic acid based hydrogels. Sol–gel fraction was determined to find out unreacted and uncross linked portion of each formulation. Invitro release study confirmed controlled release of loaded drug from PEG based polymeric matrices. Release kinetics suggested that drug release from hydrogel matrix followed solvent diffusion swelling mechanism.

This research was an attempt to synthesize a series of amphiphilic hydrogels based on different molar ratios of N,N-dimethylacrylamide (DMAM) and acrylic acid (AA) and investigated the influence of pH, time, temperature, and salinity of water on the swelling behavior of the hydrogels. The swelling kinetic parameters and swelling diffusion were also determined. The synthesis of DMAM/AA hydrogel using N,N'-methylenebisacrylamide as a cross-linking agent and AIBN as initiator was confirmed by Fourier transform infrared spectroscopy (FTIR). The swelling results revealed that the hydrogel swelling reduced as a content of AA. Also, it was demonstrated that increasing the pH caused a drastic increment of the equilibrium swelling ratio and the maximum extent (5150%) was reached at pH 14 for sample AHD3 containing 25% AA. The swelling mechanism study showed that for all samples, Fickian diffusion was responsible for water transport as well as the swelling process was considerably influenced by the chemical structure of the monomer repeating units in the synthesized samples. The swelling study of the hydrogel in the aqueous solution of NaCl and Na2SO4 showed that increasing the salt concentration caused in limitation of water absorption. Also, the swelling degree in the aqueous solution of Na2So4 was slightly higher than NaCl. It was also shown that the increase in temperature of the swelling process led to enhancement of swelling ratio in distilled water.

The present work reports the construction of polypyrrole (PPy) hydrogels directly with the as-synthesized PPy nanotubes (PPy-NTs) through infiltration of poly vinyl alcohol (PVA) and poly(acrylic acid) (PAA) solutions. This method avoids the time-consuming purification of the in-situ formed conducting hydrogels and provides a facile way to incorporate nanostructured conducting polymers evenly into the hydrogel matrix. PPy-NTs/PVA/PAA hydrogels with dual cross-linking networks were prepared through multiple freeze-thawing cycles followed by coordination with iron (III) ions. The tensile and compression strength of the hydrogels are ca. 54 kPa and 160 kPa, respectively. The PPy-NTs/PVA/PAA hydrogel was mainly electronic conducting dominated, and it showed the highest conductivity of ca. 0.04 S/cm after swollen in 0.2 M HCl (with 2wt% of PPy-NTs). Benefited from the high aspect ratio and high conductivity of PPy nanotubes, it is probable to mediate the PPy content and the integrity of the electronic conducting pathways to develop high-performance hydrogel materials used as strain sensors.

Oil shale semicoke (SC), which generated during the production of shale oil has attracted much attention in agriculture recently, as the composition of organic matter, clay mineral and else. In this study, a novel superabsorbent composite of poly(acrylic acid-co-acrylamide)/semicoke (P(AA-co-AM)/SC) was prepared by polymerization of the acrylic acid (AA) and acrylamide (AM) via a convenient one-step reaction as the presence of SC. The characterization of FTIR, SEM, XPS and TG indicated that the successful polymerization and the SC had participated into the construction of 3D polymeric network in superabsorbent. The performance testing results showed that the superabsorbent composites exhibited the excellent water absorbency, favorable water retention properties, fast swelling rate, and nice water reusability. And a 10% of SC amount could improve the water absorbency to 643.13 g/g and 79.82 g/g in distilled water and 0.9% NaCl solution, respectively. The potted culture experiments revealed that the increased water retaining capacity of soil and obvious growth promoting effect for crop. In a word, the novel superabsorbent composite could be as a potential water-saving product used in the agriculture, and the approach reported in this work also can be as a new pathway for high value using of SC via a sustainable chemical engineering process.

The resin melamine cyanurate (MCA) core-shell microcapsules were prepared by surface coatingmodification of halogen-free flame retardant MCA using melamine resin and acrylic resin as wall materials. The influence of different wall materials on the coating effect of halogen-free flame retardant MCA was studied by SEM, particle size analysis, IR, and DSC and TGA methods. The results showed that the melamine resin had a high degree of polymerization and decomposed at about 160°, which had a surface modification effect on MCA and did not affect its flame retardant performance. The surface coating rate of poly(methyl methacrylate) PMMA-MCA core-shell microcapsules was about 80%. Afteradding acrylic acid (AA) as the second monomer the coating effect was significantly improved and the thermal decomposition temperature of the wall material of the microcapsule was reduced.

Two poly(acrylic acid) (PAA)/graphene oxide nanocomposite systems, characterized by the same graphene oxide (GO) weight fraction (13.5 wt %) but with different sizes of nanoflakes, are studied by m...

Synthesis of novel semi-interpenetrating poly(acrylic acid) (PAA)/gum arabic (AG)/ZnO hydrogels by in situ free radical polymerization was optimized using response surface methodology (RSM). The reaction variables were the molar ratio of the cross-linking agent (X1), the weight percentage of gum arabic (AG) (X2) as the reaction medium, and the amount of ZnO (X3), each of which was considered at five levels. The evaluated responses in RSM based on the central composite design (CCD) were the formation of samples (Y1), swelling ratio (Y2), conversion (Y3), and percentage of networking (Y4). Zinc oxide particles (ZnO) were prepared through a cost-effective and safe method based on the mixing of zinc acetate solution, ammonia solution, and sodium hydroxide into a microwave oven. The synthesized ZnO particles and prepared semi-interpenetrating polymer network (semi-IPNs) were evaluated by energy dispersive X-ray analyzer (EDX) and scanning electron microscopy (SEM), respectively. Synthesized samples based on RSM showed that hydrogels with less than 0.75 g of gum do not have suitable desirability. Also, the confirmation of the appropriate amount of cross-linking agent in hydrogels is between 10 and 16 (mol %), and more than this amount, the desirability of the responses decreases sharply. The results showed that increasing the amount of GA, as a biological macromolecule, significantly improves hydrogel formation, swelling rate, conversion, and networking of semi-IPNs which for the sample proposed by RSM were 1, 245%, 86%, and 94.5%, respectively.

In this investigation, we decided to prepare efficient aerogel for loading and releasing drug in vitro situation. Here we introduced the synthesis of gelatin-based cross-linking poly vinyl acetate/acrylic acid aerogel and nanoclay aerogel, which synthesized by free radical condition and called gelatin-g-VA–AA (A) and gelating-VA–AA/MMT (B), respectively, and they were used them for drug delivery of diltiazem. The synthesized aerogels were completely identified by FTIR, TGA, DTG, SEM, TEM, XRD that showed nanocomposites size with about 40–70 nm, highly uniform porous surface and with high temperature stability. In addition, drug delivery activities of aerogels were tested in saline solution, temperature, the percentage of nanoclay and time effect. Moreover, pH sensitivity of aerogels was investigated for characterization of drug loading and drug releasing amounts at different pHs, distilled water and buffers to determine the best condition for each situation which results illustrated the universal buffer at pH 5 and 7 for drug loading and pH 7 and 10 for drug releasing had the least interaction with aerogels and nano-aerogel, respectively.

The anticorrosive performance of two acrylic polymers (PANa) and (PAA) on smild steel in the 0.1 M hydrochloric acid medium was investigated using numerous techniques, such as weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), Scanning electron spectroscopy (SEM), Energy-dispersive X-ray Analysis (EDAX), and DFT simulation. The obtained results through all tested methods are in good agreement. The polarization curves revealed that PANa and PAA belonged to mixed-type inhibitors. The influence of temperature on the corrosion of mild steel in 1.0 M HCl was also studied. The adsorption of PANa and PAA on mild steel surface in the studied medium follows the Langmuir isotherm. Scanning electron spectroscopy and Energy-dispersive X-ray analyses were carried out in order to study the mechanism which controls the corrosion inhibition of mild steel. Theoretical calculations realized using density functional theory (DFT), molecular dynamic (MD), and Monte Carlo (MC) simulations explored the most reactive sites of the investigated polymers.

Microgel particles composed of Interpenetrated Polymer Network (IPN) of poly(N-isopropylacrylamide) (PNIPAM) and poly(acrylic acid) (PAAc) dispersed in water have been investigated through dynamic light scattering. The study of the temperature, concentration and pH dependence of the relaxation time has highlighted the existence of a thermoreversible transition corresponding to the swollen-shrunken volume phase transition. The presence of PAAc introduces an additional pH-sensitivity with respect to the temperature-sensitivity due to PNIPAM and leads to interesting differences in the transition process at acid and neutral pH. © 2014 Elsevier B.V. All rights reserved.

A facile synthesis of near-infrared (NIR) luminescent gold cluster–poly(acrylic acid) (PAA) hybrid nanogels was developed by in situ reduction of gold salt in the core-hollow and shell-porous PAA nanogels. These Au-PAA nanogels exhibited excellent near-infrared photoluminescence properties and showed targeting potential in the optical imaging of the living body.

The formation of self-assembled microstructures of anionic polyelectrolyte, poly(acrylic acid) salts, on the surface of single-walled carbon nanotube thin films was studied by a fast phase separation process that filtrated a mixed dispersion composed of single-walled carbon nanotubes and poly(acrylic acid) derivatives on a membrane filter. The resulting microstructures of poly(acrylic acid) self-assembly were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, element mapping, and diffuse reflectance Fourier transform infrared spectroscopy. The influence factors including substrate, ion species, single-walled carbon nanotubes, and different kinds of carbon nanotubes were discussed comprehensively for the formation of microstructures of PAA self-assembly by a liquid–liquid phase separation.

We report visualization of mechanochemically assisted degrafting of surface-tethered poly(acrylic acid) (PAA) brushes in a basic aqueous buffer at nanometer to micrometer length scale by monitoring changes in local etching of silicon substrates. PAA brushes were prepared by surface-initiated atom transfer radical polymerization and incubated in 0.1 M ethanolamine buffer (pH 9.0) with 0.5 M NaCl. Morphological changes of the underlying substrates were monitored by scanning electron microscopy and atomic force microscopy. The appearance of regular-shaped pits indicated etching of the substrate, and both their number and size grew with increasing incubation time. We compared the etching behaviors for PAA, poly(methyl methacrylate) (PMMA), and poly(poly(ethylene glycol) methacrylate) (PPEGMA) brushes grafted on silicon substrates. After incubation for 7 days, the substrate of PMMA brush remained intact. In PAA brush systems, we detected the formation of a few large pits whose size grew in time. Many pits showed up on the substrate of PPEGMA brush but with substantially smaller size compared to PAA. Our findings suggest that hydrophobicity and stability of the grafted polymers play an important role in the morphological changes of the underlying silicon substrates under given incubation conditions.

In this letter, we put forward an approach to prepare hydrogen-bonded complex fibers. First, a spinnable fluid is obtained by restricting hydrogen bonds, and then it is extruded through a spinneret into a coagulation bath where hydrogen bonds are built to induce fiber formation. The hydrogen-bonded poly(acrylic acid)/poly(ethylene oxide) (PAA/PEO) complex was prepared into fibers. PAA/PEO fiber shows excellent elastic behavior and can be drawn to more than 12× its original length without breaking, which is much higher than Spandex fiber or natural rubber fiber. In the fiber, PAA and PEO are miscible in the molecular level. Dynamic hydrogen bonding between PAA and PEO restricts the crystallization of PEO, retains flexibility of polymer chains, and also provides recovery forces when removing stress.

Cyclic homo- and diblock copolymers with different topologies were synthesized using a combination of “living” radical polymerization and “click” coupling reactions. The topologies included 2- and 3-arm stars, with the arms consisting of either cyclic or linear polystyrene. In addition, a diblock consisting of a cyclic polystyrene and a cyclic poly(acrylic acid) was also made. The topologies by imposing topological constraints due to the presence of cyclic polymers and branch points had a marked influence on the glass transition temperature (Tg). It was found that for the polystyrene topology series, the Tg increased above the glass transition temperature at infinite molecular weight for a linear chain (i.e., Tg∞) and correlated to the more compact nature of cyclic polymers. For the cyclic diblock of polystyrene and poly(acrylic acid), the Tg increased significantly due to separation of the blocks into their pure phases. This resulted in significant stretching of the chains and thus loss of conformation e...

We report on the conformal coating of thickness-tunable multilayers directly onto the sulfur (S8) cathodes by the layer-by-layer (LbL) deposition for the significant improvement in the performances of Li–S batteries even without key additives (LiNO3) in the electrolyte. Poly(ethylene oxide) (PEO)/poly(acrylic acid) (PAA) multilayers on a single poly(allylamine hydrochloride) (PAH)/PAA priming bilayer, deposited on the S8 cathodes, effectively protected from the polysulfide leakage, while providing a Li+ ion diffusion channel. As a result, PAH/PAA/(PEO/PAA)3 multilayer-coated cathodes exhibited the highest capacity retention (806 mAh g–1) after 100 cycles at 0.5 C, as well as the high C-rate capability up to 2.0 C. Furthermore, the multilayer coating effectively mitigated the polysulfide shuttle effect in the absent of LiNO3 additives in the electrolyte.

We have developed the in situ fibrillation of κ-casein, employed as amyloid precursor, within multilayer films consisting of κ-casein and poly(acrylic acid) (PAA) prepared by the layer-by-layer (LbL) deposition. The fibrillation of κ-casein within the multilayered films is strongly dependent on the extent of intermolecular interactions between κ-casein and PAA. When films constructed initially at pH 3 were heat treated at the same pH, κ-casein did not transform into fibrils. However, when the films were subjected to heat treatment at pH 5, κ-casein was transformed into fibrils within multilayer films due to weakened intermolecular interactions between κ-casein and PAA. We also noted that the multilayer film was swollen at pH 5 by the charge imbalance within the film, which we believe gives enough mobility for κ-caseins to form fibrils with adjacent κ-caseins within the multilayer. The fibrils were found to be uniformly distributed across the entire film thickness, and the aspect ratio as well as the number density of fibrils increased as a function of incubation time. The present study reveals a strategy to realize in situ nanocomposites within LbL multilayer films simply by triggering the formation of protein fibrils by controlling the intermolecular interactions between amyloid precursors and polyelectrolytes (PEs).