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Acrylic acid (AA) is an important and widely used industrial chemical, but its high toxicity renders its use incompatible with the concept of green development. By leveraging its terminal carboxyl group and unsaturated bond, we designed and explored a new strategy to increase the greenness of AA via its eutectic melting using a quaternary ammonium salt (choline chloride) to form a deep eutectic solvent (DES), followed by polymerisation of the DES to form a polymer (poly(DES)). The greenness of AA, DES, and poly(DES) was evaluated via an in vitro test using MGC80-3 cells and an in vivo test using Kunming mice. The toxicity improved from Grade 2 (moderately toxic) for AA to Grade 1 (slightly toxic) for DESs and Grade 0 (non-toxic) for poly(DES) in the in vitro test. Moreover, the poly(DES)s showed a lower toxicity in mice than the DESs in the in vivo test. Thus, greenness enhancement was successfully achieved, with the greenness following the order AA

Background: Due to the emergence of resistance to available anticancer agents, the demand for new cytotoxic agents has grown. Objective: This study aims at synthesis and cytotoxic evaluation of new acrylic acid derivatives bearing quinolinone and halogenated quinolinone derivatives against three cancer cell lines. Methods: New acrylic acid derivatives bearing quinolinone and halogenated quinolinone moieties were synthesized and screened for their cytotoxic activity against breast MCF-7, liver HepG2, and colon HCT-116 cancer cell lines. Results: Molecules 3 and 8 showed the most potent cytotoxic activity against HCT-116. DNA flow cytometry assay showed cell cycle arrest at the G1 phase and cellular apoptosis. Moreover, molecules 3 and 8 showed cyclin-dependent kinase 2 (CDK2) inhibitory activity compared to the untreated control sample. Conclusion: Acrylic acid derivatives bearing quinolinone and halogenated quinolinone moieties represent an important core and could be used as a lead for further development of drug compounds in order to achieve promising therapeutic results.

PVDF membrane has strong hydrophobicity and low anti-pollution performance, greatly limiting its practical application. These drawbacks have been successfully overcome by designing and then preparing a membrane with a semi-interpenetrating polymer (semi-IPN) of PVDF/poly(acrylic acid) (PAA) as the membrane matrix, TiO2 nanoparticles as functional components and F127 as pore-forming agent. The semi-IPN was prepared by copolymerizing acrylic acid with N,N methyl acrylamide in the presence of PVDF, and the TiO2 gel nanoparticles were in situ formed in the membrane-forming process. The properties of the composite membrane were significantly affected by the semi-IPN, F127 and TiO2. By adjusting the membrane structure with the semi-IPN, F127 and TiO2 nanoparticles, we prepared a composite membrane with a water contact angle of 40o, a BSA rejection ratio of 87.5% and a water flux of 802.5 L/m2/h/bar. After a simple UV irradiation, the water flux of this composite membrane rose to 1030 L/m2/h/bar, without any rejection decline. The membrane contaminated by humic acid could recover the water flux up to above 95.3% of its original value by a single UV irradiation, showing a very good antifouling performance. In addition, the composite membrane also exhibited a very strong pollution resistance and separation performance for bovine serum albumin and oil-water emulsion. All in all, based on the synergy of the semi-IPN and the evenly dispersed TiO2 nanoparticles, the prepared composite membrane exhibited excellent comprehensive properties and demonstrated a great potential for various separation applications.

In the present study we are interested in designing theoretical and experimental approach for the production of acrylic acid (AA) from lactic acid (LA) over various zeolite catalysts: synthetic BEA and natural clinoptilolite CLI zeolites modified with metals (Sn, Co, Cu and Fe). The catalysts were prepared using an ion exchange method. In the theoretical studies the metal M-O-M dimers were found to be stable above oxygen bound with aluminium centres of BEA and CLI zeolites. The mechanism of direct lactic acid dehydration in Sn-, Co-, Cu- and Fe-BEA zeolites was found inside the zeolites pores and in the hierarchical/surface model. Experimentally, the investigated catalysts set trends in the following by-product formation: acrylic acid, pyruvic acid (PAC), 2,3-pentanedione (2,3-PD) or acetaldehyde (AC). Based on the collected results, the following types of LA conversion reactions can be proposed: dehydration to AA, decarboxylation to acetaldehyde, hydrogenation to 2,3-pentanedione, oxidation to acetic acid, reduction to propionic acid, oxidative dehydrogenation to pyruvic acid, condensation to 1,2-propanediol.

The design of heterogeneous catalysts is challenged by the complexity of materials and processes that govern reactivity and by the fact that the number of good catalysts is very small in comparison to the number of possible materials. Here, we show how the subgroup-discovery (SGD) artificial-intelligence approach can be applied to an experimental plus theoretical data set to identify constraints on key physicochemical parameters, the so-called SG rules, which exclusively describe materials and reaction conditions with outstanding catalytic performance. By using high-throughput experimentation, 120 SiO2-supported catalysts containing ruthenium, tungsten, and phosphorus were synthesized and tested in the catalytic oxidation of propylene. As candidate descriptive parameters, the temperature and 10 parameters related to the composition and chemical nature of the catalyst materials, derived from calculated free-atom properties, were offered. The temperature, the phosphorus content, and the composition-weighted electronegativity are identified as key parameters describing high yields toward the value-added oxygenate products acrolein and acrylic acid. The SG rules not only reflect the underlying processes particularly associated with high performance but also guide the design of more complex catalysts containing up to five elements in their composition.

In this study, we report the development of physically cross-linked hydroxyethyl cellulose grafted polyacrylic acid-co-polyacrylamide/silver nanocomposite [Ag@HEC-g-P(AA-co-AM)-Fe3+] possesses excellent antimicrobial and enhanced MB adsorption. A green in-situ reduction process was used to prepare silver nanoparticles. UV-Vis spectroscopy, TEM, ATR-IR, XRD, SEM-EDS were used to analyze the green produced silver nanoparticles and Ag@HEC-g-P(AA-co-AM)-Fe3. The swelling ratio of Ag@HEC-g-P(AA-co-AM)-Fe3+ is dependent on AgNPs content and pH. The swelling kinetics fitted with Pseudo-second order. The cumulative release % of AgNPs was 29.63 ± 1.7%, respectively up to 10 h and its kinetics obey Korsmeyer-Peppas model. The grafting to HEC and incorporation of AgNPs into HEC-g-P(AA-co-AM)-Fe3+ enhances the thermal stabilities and increases total activation energies from 19,122.2 to 66,287.1 KJ mol. Ag@HEC-g-P(AA-co-AM)-Fe3+ has powerful antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Micrococcus leutus, Staphyllococus aureus. The maximum adsorption capacity of MB was 133.38 ± 1.25 mg/g at nanocomposite concentration (300 mg/L), pH (9.0), and MB concentration (5 mg/L). To anticipate the adsorption mechanism, Pseudo-first and second-order models, as well as three isotherm models (Langmuir, Freundlich, and Temkin) were used to model adsorption kinetics. The nonlinear Langmuir models and second-order kinetics were the most appropriate.

Responsive photonic crystals have attracted much attention due to their strong capability to manipulate the propagation of light in the visible region, but it is still a big challenge to invisibility and mechanical stability. Here, the novel Poly(ether sulfone)/Poly(acrylic acid) inverse opal photonic crystals, which have high mechanical stability and can release visible patterns after wetting with water, are discussed. The Poly(ether sulfone)/Poly(acrylic acid) inverse opal photonic crystals are also responsive to the concentration of ethanol, and the structural color response times increase with increasing ethanol concentration. This design uses the selective infiltration, hydrogen bonding and capillary action of solvent to realize the spectral diversity of reflectance. Owing to the high polarity and hydrogen bonding ability of carboxyl groups, water molecules are adsorbed easily by the poly(acrylic acid) gel. Subsequently, the encrypted information is decrypted due to the redshift of the structural color. Because of its lower polarity and hydrogen bonding ability relative to water, ethanol can impede the absorption of solvent by gel. Therefore, the ethanol concentration can be identified based on the structural color response time. Furthermore, reliable information decryption methods make Poly(ether sulfone)/Poly(acrylic acid) inverse opal photonic crystals potentially uesful as trusted encryption devices.

Multifunctional hydrogels with transparency, ultraviolet (UV)-blocking, stretchable, self-healing, adhesive, antioxidant and antibacterial properties are promising materials for biomedical and relevant applications. However, preparation of these hydrogels at ambient environment without stimuli is still a challenge. Here, a series of hydrogels possessing ultrashort gelation time (~30 s) at room or cold temperature were fabricated based on self-catalytic Fe3+/Tannic acid-cellulose nanofiber (Fe3+/TA-CNF). Fe3+/TA-CNF formed stable redox pairs to activate ammonium persulfate (initiator), generating abundant free radicals to trigger the ultrafast polymerization of acrylic acid (AA). To improve the antibacterial ability of hydrogel, a bilayer hydrogel composite (NF@HG) composed of tetracycline hydrochloride (TH)-loaded electrospun nanofibers and hydrogel layer was fabricated via a mild casting method. The NF@HG exhibited enhanced antibacterial ability and the sustained release of TH can provide long-term antibacterial activity. Besides, cell viability results demonstrated that NF@HG was non-cytotoxic. Taken together, this strategy based on self-catalytic Fe3+/TA-CNF system may inspire new aspects on fast and economical preparation of multifunctional hydrogels or composites, which have attractive industrial applications for biomedical materials.

Strain-sensitive and conductive hydrogels have attracted extensive research interest due to their potential applications in various fields, such as healthcare monitoring, human–machine interfaces and soft robots. However, low electrical signal transmission and poor tensile properties still limit the application of flexible sensing hydrogels in large amplitude and high frequency motion. In this study, a novel ionic liquid segmental polyelectrolyte hydrogel consisting of acrylic acid (AAc), 1-vinyl-3-butylimidazolium bromide (VBIMBr) and aluminum ion (Al3+) was prepared by molecular design and polymer synthesis. The cationic groups and amphiphilicity of ionic liquid chain segments effectively improve the tensile behavior of the polyelectrolyte hydrogel, with a maximum tensile strength of 0.16 MPa and a maximum breaking strain of 604%. The introduction of ionic liquid segments increased the current carrying concentration of polyelectrolyte hydrogel, and the conductivity reached the initial 4.8 times (12.5 S/m), which is a necessary condition for detecting various amplitude and high frequency limb movements. The flexible electronic sensor prepared by this polyelectrolyte hydrogel efficiently detects the movement of different parts of the human body stably and sensitively, even in extreme environment (−20 °C). These outstanding advantages demonstrate the great potential of this hydrogel in healthcare monitoring and wearable flexible strain sensors.

A site-specific functionalized novel bio-adsorbent (seed composite; MOLL) was used for the remediation of toxic metal ions from the water bodies. The graft co-polymerization using acrylic acid has been carried out onto the polyvinyl alcohol encapsulated seed composite to enrich the bio-adsorbent surface with numerous active carboxylic functionalities responsible for the enhancement in the remediation of cationic metal ions from aqueous system. The morphology, surface area, porosity, presence of functionalities and thermal stability were characterized using SEM-EDX, BET, FTIR and TGA. The functionalized bio-adsorbent (AA-g-PVA-SC-en) exhibited excellent remediation of metals (Pb2+, Cd2+, Cr3+and Ni2+) in the range (90% − 98%) with adsorption capacity (22.44 – 24.73 mg/g). The adsorption capacities in both a single metal and multi-metal system far exceeds from other bio-adsorbents reported so far. The regeneration of functionalized bio-sorbent remained up to six cycles. The findings open up new avenues for the development of a green pre-treatment approach for water remediation, prior to the large scale chemical treatment.

Gel electrolytes based on poly(acrylic acid) and poly(ethylene glycol)diacrylate (PAA-PEGDA-Ca2+) loaded with Ca2+ ions were successfully prepared using gamma irradiation. The use of radiation provides benefits, such as solventless preparation without byproducts. The obtained gel fraction, porosity, and swelling ratio were in the range of 60–90%, 11–60%, and 4–12 g/g, respectively. Fourier transform infrared spectroscopy confirmed the successful crosslinking between PAA and PEGDA. Crystallinity remained unaffected by the incorporation of Ca2+ ions. The thermal decomposition of the gels started at 200°C. The morphology was reported to have a spherical shape. 0.36-0.74 wt.% of Ca2+ was uniformly distributed on the gel electrolyte surface. In the presence of Ca2+ ions, the ionic conductivity of the gels improved by ∼2 times, whereas compressive strength slightly dropped to the range of 6–12 MPa. Graphical abstract Download : Download high-res image (122KB) Download : Download full-size image

A novel CaCO3 nanoparticle modification method by a styrene-acrylic polymer emulsion (SAPE) was introduced. The self-made SAPE was sprayed into the nano-CaCO3 slurry system, and SAPE chains were encapsulated onto the CaCO3 nanoparticle surface. The modified CaCO3 nanoparticle mechanism was discussed. Fourier transform infrared spectroscopy confirmed that the SAPE chain was anchored on the nano-CaCO3 surface by the reaction of the SAPE carboxyl group with the hydroxyl group on the CaCO3. The effect of acrylic acid (AA) amount on the activation degree and oil absorption of CaCO3/SAPE composite nanoparticles was investigated. The amount of AA was 2%, and the activation degree and oil absorption of the product were optimal. The estimated grafting efficiency of the CaCO3/SAPE composite nanoparticles was 90.5% when the amount of acrylamide (AAM) was 1.5%. Scanning electron microscopy showed that the CaCO3 nanoparticles could be dispersed uniformly in polypropylene (PP) film and formed a closed integration by SAPE-modified CaCO3. The styrene-acrylic polymer chains that were grafted on the CaCO3 nanoparticle surface could improve the compatibility between the CaCO3 nanoparticles and PP matrix. The PP composite film with modified CaCO3 nanoparticles had a higher tensile strength than that of pure CaCO3 nanoparticles, which can improve the mechanical properties of the PP material.

Two new phenolic acids (1‒2), one new phenolic glycoside (3) and one new natural compound, 3-(4-hydroxy-3-methoxy-phenyl)acrylic acid carboxymethyl ester (6), together with eleven known polyphenolic substances, ferulic acid (4), ethyl ferulate (5), (E)-3–4-hydroxy-3-methoxyphenyl)acrylic acid (7), 3,4-dihydroxy benzaldehyde (8), quercetin (9), quercetin-3-O-glucopyranoside (10), luteolin (11), luteolin-7-O-rutinoside (12), diosmetin (13), diosmetin-3′-O-β-D-glucopyranoside (14), and apigenin-6,8-di-C-β-D-glucopyranoside (15) were isolated and identified from Hyssopus cuspidatus Boriss for the first time. The structures of the new compounds were elucidated from the spectra of 1D NMR, 2D NMR, IR, UV and MS data. Compounds 1–15 were tested to determine their inhibitory effect on lipopolysaccharide (LPS)-induced NO production in RAW 264.7 cells. Novel compound 3 exhibited significant anti-inflammatory activity with an IC50 value of 35.88 μM, which was comparable to that of dexamethasone (positive control). This study provided phytochemical evidence for the further development of new anti-inflammatory lead compounds and investigation of their chemical modification and mechanism.

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.

Lignocellulosic biomass is a promising renewable feedstock for the sustainable manufacturing of biofuels and bioproducts. Among emerging bioproducts, 3-hydroxypropionic acid (3-HP) is of particular...

Synthesis of polymer nanogels (NGs) for biomedical applications is considered to be a very promising application in radiation engineering. Under high-dose pulse irradiation of dilute aqueous polymer solution, reactive species generated by water radiolysis can create multiple radicals on each macromolecule and consequently induce intramolecular cross-linking of polymer chains, resulting in NG formation. The obtained products are free from harmful monomers, initiators, and cross-linking agents, which makes them potentially applicable for drug delivery applications. One of the biggest challenges in handling and use of nanoparticles, however, is the colloidal stability, when aqueous suspensions are stored for prolonged periods. Therefore, development of the best protocols for the particular nanocarrier storage is key. To address this need, we have performed the prospective study in which we systematically assessed the influence of various processing and storage scenarios feasible in our lab, on the colloidal stability of the radiation-synthesized poly(acrylic acid) (PAA) NG particles in suspension. This allowed us to choose the optimal way of handling the product after its synthesis. We confirmed that none of the strategies we used and tested are substantially detrimental to our product. Filtration with 0.2-μm filters was proven sufficient for sample purification and prolonged storage in aqueous suspension did not exert a negative effect on the colloidal stability of particles suspension. We have also demonstrated that lyoprotectant-free lyophilization was suitable for our polymer nanoparticles. This is an important fact for further application of particles as nanocarriers for biologically active compounds such as targeting ligands or therapeutic moieties.

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.

It is desirable to fabricate an antifatigue gel for skin-mimicking sensors on the demand of long-term durability in practical usage. Here, we developed a physically cross-linked eutectogel based on a poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) binary polymer skeleton and a deep eutectic solvent (DES). In this eutectogel, uniformly distributed PVA crystalline domains acted as stable physical cross-linkers, and high-density hydrogen bonds possessed great reversibility. Such a polymer network structure was expected to endow this eutectogel with excellent mechanical strength, stretchability, and a self-recovery ability. Specifically, this eutectogel exhibited a superior tensile strength of 2.6 MPa, a fracture strain of 680%, and a fracture toughness of 8.39 MJ m-3. In cyclic stretching/releasing tests with a fixed strain of 100%, this eutectogel could recover its mechanical properties within a 600 s resting time. Based on this self-recoverable eutectogel, a reliable flexible sensor was fabricated, which possessed good sensitivity and stability over a wide strain range (1-300%). More importantly, the flexile sensor was able to maintain a highly repeatable response signal during 1000 consecutive stretching/releasing cycles, showing outstanding long-term durability. Given the excellent sensing performance, this eutectogel has promising potential in wearable electronics, human-machine systems, and soft robotics.

The rheological properties of the gel-like material, the monomer of which is a crosslinked and modified 2-propenamide of acrylic acid, were determined by relaxation rheometry methods. The values of its elastic modulus and modulus of losses and complex viscosity depending on: deforming stress and its frequency are determined; relative deformation; temperature in the range (20-100) ° C and the regularities of these dependences are noted. It is established that: 1) the dependence of the modulus of elasticity (G'); modulus of loss (G'') and complex viscosity from: relative deformation; voltage; temperature; frequencies indicate that in the linear scale they change according to nonlinear dependencies, and in the transition to the logarithmic scale contain plateau-like areas; 2) analytical dependences of the above parameters on stress, strain rate and temperature are complex and difficult to establish; 3) in the range (20-80) ° C and relative deformations (10-100)% hydrogel has a virtually unchanged value of the modulus (G ') ten times greater than the modulus (G' '), whichdetermines the uniqueness of its rheological and biophysical properties ; 4) in the region (20-80) ° C hydrogel in terms of modulus of elasticity and tangent of the angle of loss is close to a completely elastic body; 5) when the frequency of the deforming voltage is more than 15.8 Hz and the relative deformation ≥100%, the gel is brittlely deformed; while the modulus of its elasticity decreases abruptly and the modulus of losses increases rapidly with increasing frequency of the deforming stress. 6) the dependence of the elastic-viscosity characteristics of the samples washed and unwashed in saline gel in the temperature range (20-80) ° C differ little and indicate that the equilibrium structure of the hydrogel 2-propenamide acrylic acid belongs to the typical colloidal dispersed structure of gelatinous substances.

Photodynamic therapy (PDT) is a clinical treatment based on the activation of light-absorbing photosensitizers (PS) to generate reactive oxygen species, which are toxic to the targeted disease cells. Because most PS are hydrophobic with poor water solubility, it is necessary to encapsulate and solubilize PS in aqueous conditions to improve the photodynamic action for this compound. In this work, gelatin-poly(acrylic acid) nanoparticles (PAA/gelatin nanoparticles) via template polymerization for incorporation aluminum chloride phthalocyanine (ClAlPc) as a model drug for PDT application were developed. Biocompatible core-shell polymeric nanoparticles were fabricated via template polymerization using gelatin and acrylic acid as a reaction system. The nanoparticulate system was studied by scanning electron microscopy, steady-state, and their biological activity was evaluated using in vitro cancer cell lines by classical MTT assay. The obtained nanoparticles had a spherical shape and DLS particle size were determined further and was found to be around 170 nm. The phthalocyanine-loaded-nanoparticles maintained their photophysical behaviour after encapsulation. It is found that ClAlPc can be released from the nanoparticles in a sustained manner with a small initial burst release. In vitro cytotoxicity revealed that ClAlPc-loaded nanoparticles had similar cytotoxicity to free ClAlPc with mouse melanoma cancer cell line (B16-F10). In vitro photoeffects assay indicated that the nanoparticle formulation was superior in anticancer effect to free ClAlPc on mouse melanoma cancer cell line B16-F10. The results indicate that ClAlPc encapsulated in gelatin-poly(acrylic acid) nanoparticles are a successful delivery system for improving photodynamic activity in the target tissue.

An aqueous Zn-MnO2 battery with high energy density and good cyclability has been successfully developed with use of an ‘oversaturated gel electrolyte’ (OSGE) prepared by cost-effective acetates and poly(acrylic acid) at 75°C. The electrochemical stability window of the OSGE was extended to 3.45 V at room temperature and was able to maintain this window in temperatures up to 80°C. The ionic conductivity of the OSGE was 3.74 × 10−3 S•cm−1 at room temperature. Molecular dynamics simulation was employed to investigate the contacted cation solvation sheath and could be used to account for the excellent stability of the acetate OSGE. On utilisation of the electrolyte, a high reversibility was demonstrated at room temperature, with 600-hour stripping/plating on Zn metal electrodes and no formation of dendrites. The Zn-MnO2 battery successfully operated for 2000 cycles under an over-charge working voltage (2.0 V). This study not only overcomes the limitation associated with the solubility of salts, but also provides a feasible route for developing a highly stable aqueous Zn-MnO2 battery.

Lumefantrine (LMF), a high-mobility and easy-to-crystallize WHO drug for treating malaria, can form an amorphous salt with poly(acrylic acid) (PAA) that is remarkably stable against crystallization at high humidity and temperature and has fast dissolution rate. The amorphous salt up to 75% drug loading was synthesized under a mild slurry condition easily implemented in basic facilities for global health. Salt formation was confirmed by IR spectroscopy and the much elevated glass transition temperature. At 50% drug loading, the amorphous salt resists crystallization for at least 18 months under the highly stressful condition of 40 °C and 75% RH. In contrast, the dispersion containing neutral LMF in PVP fully crystallized in 4 d and the dispersion in HPMCAS, a weak polyelectrolyte of lower charge density than PAA, crystallized by 50% in 7 d. The amorphous salt at 50% drug loading showed much faster dissolution than crystalline LMF: In SGF, the area under the curve (AUC) was 30 times larger within the gastric emptying time (4 h); in FaSSIF, the enhancement was even larger – by 200 times. Nanodroplets were detected during the dissolution in SGF, possibly accounting for the apparent enhancement of dissolution rate. The LMF-PAA example as a challenging case, along with the previously reported clofazimine-PAA, demonstrates the general utility of amorphous drug–polymer salts to achieve high stability under tropical conditions and enhanced dissolution and bioavailability.

In this study, the impact of particle form of the Cannabis indica plant biofibers and the fiber’s surface tailoring on the physical, thermal, dielectric, and mechanical properties of unsaturated polyester composite specimens manufactured utilizing nonconventional materials were investigated. The mechanical properties such as compressive, flexural, and tensile strengths of the composite specimens were noticed to increase after functionalization of biofiber with acrylic acid and maximum enhancement was found at 20% of biofiber sacking. The physical characterization was concentrated on the assurance of the dielectric constant, dielectric strength, dielectric loss, moisture absorption, chemical resistance, percentage of swelling, limiting oxygen index, and biodegradation of polymer composites under red soil. An increase in dielectric strength from 28 to 29 kV, limiting oxygen index values from 19% to 23%, and moisture/water absorption behavior was noted for resulted bio-composites after surface tailoring of biofiber. To assess the deterioration of the polymeric materials with the temperature, differential scanning calorimetric and the thermogravimetric tests were carried out and enhancement in thermal stability was noted after fortification of polyester composites with functionalized biofiber.

Pectin grafted polyacrylic copolymer hydrogels were made by free radical crosslink copolymerization of acrylic acid (AA) and acrylamide (AM) in an aqueous solution of pectin. N′N-methylene bis acrylamide (MBA) was used as a crosslinker. During the polymerization reaction the attapulgite (APG) filler was also incorporated in situ into the network of the copolymer gel. Several filled hydrogels were prepared by varying the amount of pectin and APG filler. These hydrogels were characterized by FTIR, 13C NMR, XRD, TGA, SEM, mechanical properties, DMA, swelling, diffusion characteristics and network parameters. The release kinetics of a model drug diltiazem hydrochloride (DT) was studied with these hydrogels. The wt% of pectin, APG and MBA was optimized with a central composite design (CCD) model of response surface methodology (RSM) with equilibrium swelling ratio (ESR), drug adsorption (mg/100 mg gel) and drug release% in 16 h as response. Accordingly, the hydrogel prepared with 5:1 AA:AM molar ratio, 25 wt% monomer concentration, 1% each of initiator and MBA concentration, 18 wt% pectin and 2 wt% APG showed an optimized ESR of 17.75, drug loading of 27.58 and a drug release % of 92.5 in 16 h at a solution pH of 7.4.

As one of the most sustainable resources, wood has been widely used in the fields of construction, decoration, flooring and furniture. The emergence of transparent wood further expands the application fields of wood to solar cells, luminescent magnetic switches, artificial electronic skins and stress sensors. However, most of the transparent woods reported are obtained by impregnating resins such as polymethylmethacrylate (PMMA), epoxy resin (EP) and polyvinylpyrrolidone (PVP). Here, we demonstrated a flexible transparent wood prepared based on a deep eutectic solvent composed of acrylic acid and choline chloride. The light-absorbing chromophore group of natural wood was removed by the sodium chlorite delignification method to obtain the treated wood template, then the deep eutectic solvent was infiltrated into the wood template, and the final transparent wood was obtained by photo-initiated polymerization. This transparent wood has excellent stretchability (maximum tensile strain up to 73.9%), flexibility and tensile resilience. Moreover, this transparent wood also has good electrical conductivity and temperature sensing properties. The electrical signal of transparent wood has very favorable stability and repeatability in multiple heating–cooling cycles, indicating its great potential as a temperature sensor.

In this research, high-performance epoxy acrylate (EA) coating formulations that contain various acrylate-modified diepoxy siloxane (DESA) intermediates were synthesized and characterized. Firstly, diepoxy siloxane (DES) intermediates, which have varying chain lengths (Mw = 370–3300 Da), were modified by acrylic acid via the ring-opening reaction oxirane group. DESA intermediates were then used in the preparation of ultraviolet (UV)-curable EA formulations. EA was also synthesized via acrylic acid modification of a commercial bisphenol-A-based epoxy resin, used as the standard formulation. EA-based UV-curable formulas were applied on substrates and then cured by UV irradiation for investigating the coating performances. Subsequently, performances of the UV-cured coatings were evaluated by the various test techniques, such as hardness, gloss, cross-cut adhesion force scratch resistance, contact angle, yellowing resistance, abrasion resistance, chemical resistance, and color measurement. The effect of DESA variety on the formations was examined compared to both themselves and the standard formulation. The results showed that the varying amounts and chain lengths of DESA influenced UV-curable coatings’ properties; particularly, the scratch resistance, contact angle, and yellowing resistance significantly enhanced with the increasing chain length of DESA. High-performance UV-curable EA formulations could be produced with the scratch resistance of 4 N, the contact angle of 95°, and high yellowing resistance (ΔE = 0.35).

Effective control of monomer diffusion and reaction rate is the key to achieving a controlled interfacial polymerization (IP) and a high-performance nanofiltration (NF) membrane. Herein, an integration of multirole regulations was synchronously realized using poly(acrylic acid) (PAA) as an active additive in a piperazine (PIP) aqueous phase. Thanks to synergistic interactions, including hydrogen bonding, electrostatic interaction, and covalent bonding between PAA and PIP molecules, together with the increased viscosity of the solution, PIP diffusion was rationally controlled. Moreover, interfacial polycondensation was also restrained via the modestly reduced pH of the aqueous solution. These contribute to the formation of a thinner, looser, more hydrophilic, and higher negatively charged PAA-decorated polyamide selective layer with a unique nanostrand-nodule morphology. The harvested NF-PAA/PIP membrane showed an ∼70% rise in water permeability (up to 23.5 L·m-2·h-1·bar-1) while retaining high Na2SO4 and dye rejections. Furthermore, the optimized NF-PAA/PIP membrane presented a superior fouling resistance capability for typical pollutants, as well as long-term stability during successive filtration. Thus, this work offers a straightforward and impactful approach to regulating IP and promoting NF membrane properties.

Dimethyl sulfide (DMS) is an important and dominant trace gas that is transferred from the ocean to the atmosphere; however, the production of DMS from marine algae is still rudimentary, with the enzymatic cleavage of dimethylsulfoniopropionate (DMSP) to DMS and acrylic acid (AA), one of the main considered pathways. Dissolved DMSP (DMSPd) was supplied to batch cultures of Prorocentrum minimum at different algal growth stages and the kinetics of overall DMSPd consumption and DMS (AA) production were investigated. The kinetics of overall DMSPd consumption and DMS (AA) production from DMSPd were different during the growth cycle. The cultures displayed Michaelis–Menten-type kinetics for DMS production during the entire growth period, which yielded an apparent half-saturation constant (Km(app)) value of 37.8 ± 12.8 μM and a maximum rate (Vmax) value of 75.6 ± 12.2 nmol min−1 (1010 cells)−1. The production rates of AA had a nearly linear fit over the concentration range of the added DMSPd except during mid-exponential growth phase. A Km(app) value of 1.73 ± 0.75 μM and a Vmax value of 2.36 ± 0.12 μmol min−1 (1010 cells)−1 were observed. The ratio of DMS/AA increased with the concentration of the added DMSPd, which was less than 12% during the entire growth period. The low ratios of DMS/(DMSP + AA), which ranged from 0.01 to 1.83%, demonstrate that degradation of DMSP tends to take a non-DMS-production pathway. The ratios of AA/(DMSP + AA) varied from 9 to 95% during the stationary phase and from 6 to 69% during the senescent phase and declined with substrate concentration when different concentrations of DMSPd were added. The degradation ratios of DMSPd were related to the initial concentrations of DMSPd.

Alkali-oxygen one-bath scouring and bleaching process of the flax roving was studied by using a new type of synthesized non-silicon oxygen bleaching stabilizer Poly(acrylic acid) magnesium instead of sodium silicate. Based on the analysis of the effects of single factors such as sodium hydroxide concentration, hydrogen peroxide concentration, temperature, time and the amount of the synthesized non-silicon oxygen bleaching stabilizer poly(acrylic acid) magnesium salt on the performance of the bleached flax roving, including the whiteness, the breaking tenacity, the capillary effect and the weight loss ratio. The optimal process for the application of the stabilizer was determined by orthogonal test, namely, hydrogen peroxide concentration 8.5 g/L, sodium hydroxide concentration 5 g/L, sodium bisulfite 3 g/L, sodium carbonate 3 g/L, the synthesized non-silicon oxygen bleaching stabilizer poly(acrylic acid) magnesium 5.5 g/L, scoured and bleached at 90 °C for 60 min, and the bath ratio was 25:1. Compared with the traditional oxygen bleaching stabilizer sodium silicate, it not only has good ability to inhibit the rapid decomposition of hydrogen peroxide, but also has the advantages of higher whiteness, higher capillary effect, good feel and breaking tenacity, and can effectively solve the "silicon scale" problem and improve the quality of flax products. A novel non-silicon oxygen bleaching stabilizer poly(acrylic acid) magnesium was synthesized and successfully applied to alkali-oxygen one-bath scouring and bleaching process of the flax roving, effectively solving the "silicon scale" problem caused by conventional sodium silicate as stabilizer.

This article takes a step forward in understanding the mechanisms involved during the preparation and performance of cross-linked high-drug-loading (HDL) amorphous solid dispersions (ASDs). Specifically, ASDs, having 90 wt % poorly water-soluble drug indomethacin (IND), were prepared via in situ thermal cross-linking of poly(acrylic acid) (PAA) and poly(vinyl alcohol) (PVA) and thoroughly evaluated in terms of physical stability and in vitro supersaturation. Results showed that HDL ASDs having excellent active pharmaceutical ingredient (API) amorphous stability and prolonged in vitro supersaturation were prepared by fine tuning the cross-linking procedure. Unraveling of the processes involved during ASD's formation shed light on the significant role of the cross-linking conditions (i.e., temperature and time), the physicochemical properties of the API, and the hydrolysis level of the cross-linker as key factors in modulating ASD's stability. In-depth analysis of the prepared systems revealed the (1) reduction of API's molecular motions within the cross-linked polymeric networks (through API's strong spatial confinement), (2) the structural changes in the prepared cross-linked matrices (induced by the high API drug loading), and (3) the tuning of the cross-linking density via utilization of low-hydrolyzed PVA as the major mechanisms responsible for ASD's exceptional performance. Complementary analysis by means of molecular dynamics simulations also highlighted the vital role of strong drug-polymer intermolecular interactions evolving among the ASD components. Overall, the impression of the complexity of in situ cross-linked ASDs has been reinforced with the excessive variation of parameters investigated in the current study, offering thus insights up to the submolecular level to lay the groundwork and foundations for the comprehensive assessment of a new emerging class of HDL amorphous API formulations.

PAA/nHAp was synthesized by solvent casting method and characterized by different techniques. nHAp was homogeneously dispersed in nano-sized in PAA matrix. The thermal properties and glass transiti...

In this study, it was investigated experimentally the influence of various solvents (distilled water and ethanol) on the solution properties, spinning performance, and fibre morphology of the electro spun Poly (acrylic acid) nanofibers. Firstly, polymer solutions were prepared at 5 wt % PAA with various solvent ratios of ethanol and distilled water. Then, solution properties such as viscosity, density, pH, conductivity, and surface tension were determined. The production of nanofiber samples was carried out by electrospinning under the optimum process parameters (voltage, distance between electrodes, feed rate, and atmospheric conditions). Finally, the morphological characterization of the nanofiber surface was carried out with SEM. According to the results, it was observed that conductivity, surface tension and the density of the solution increase as the ethanol ratio decreases. On the other hand, pH value increases as the ethanol ratio increases and, so, the acidic value of the solutions decreases. The viscosity increased until the ethanol/distilled water ratio was 50/50 and then decreased as the ethanol percentage decreased to under 50%. In addition, average fibre diameter decreases with ethanol ratio decreases. It is possible to say that solvent type affects solution properties, fibre morphology and spinning performance significantly. Generally, fine, uniform and bead free nanofibers could be electro spun and the PAA solution containing 70 wt % distilled water and 30 wt % ethanol was selected as the optimum in terms of fibre morphology, web quality and spinning performance.

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...

Using N-isopropylacrylamide (NIPAM) and acrylic acid (AAc) as monomers, N,N′-methylenebisacrylamide (MBA) as a cross-linking agent, and molybdenum disulfide (MoS2) as functional particles, a P(NIPAM-co-AAc)/MoS2 composite hydrogel was prepared by free radical polymerization initiated by ultraviolet light. The results of Fourier transform infrared spectroscopy, Raman spectroscopy, and scanning electron microscopy show that MoS2 has been successfully introduced into the P(NIPAM-co-AAc) system, and the obtained composite hydrogel has a porous network structure. Studies on the swelling property and dye adsorption performance show that the addition of MoS2 can increase the swelling ratio of P(NIPAM-co-AAc) hydrogels to a certain extent and can significantly improve the ability of the P(NIPAM-co-AAc) hydrogel to adsorb methylene blue (MB). The adsorption process of MB by the composite hydrogels conforms to the pseudo-second-order kinetics and the Langmuir isotherm adsorption models. The estimated equilibrium adsorption capacity (Qm) using the Langmuir isotherm model can reach 1258 mg/g, mainly due to the electrostatic interaction between the negatively charged groups −COO– and MoS2 particles on the network structure and the positively charged dye MB. The adsorption of MB by P(NIPAM-co-AAc)/MoS2 composite hydrogels depends on the temperature during adsorption. Compared with room temperature, a high temperature of 40 °C above the poly(N-isopropylacrylamide) (PNIPAM) phase transition temperature (∼32 °C) leads to a decreased adsorption capacity of the P(NIPAM-co-AAc)/MoS2 composite hydrogel for MB due to the enhanced hydrophobic properties of the network structure and the decrease of the swelling ratio. The prepared hydrogel material can be used as a good adsorbent for dyes, which is promising in wastewater treatment.

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.

The thermal decomposition of polyethylene glycol fumarate–acrylic acid copolymer is investigated at different rates of heating. It is shown that increasing the rate of heating raises the temperature of the onset of decomposition. The kinetic parameters of decomposition are calculated using the integral Kissinger–Akahira–Sunose procedure. It is found that at different degrees of conversion, the activation energies are very close: E = 205–227 kJ/mol. The effect the composition of the copolymer has on the results from kinetic calculations is shown. The Coates–Redfern approach is used to determine the pre-exponential factor and the model of thermal decomposition. Calculated thermogravimetric curves are constructed and compared to experimental ones.

Immobilization of enzymes onto carriers is a rapidly growing research area aimed at increasing the stability, reusability and enzymolysis efficiency of free enzymes. In this work, the role of phase-separation and a pH-responsive “hairy” brush, which greatly affected the topography of porous polymer membrane enzyme reactors (PMER), was explored. The porous polymer membrane was fabricated by phase-separation of poly(styrene-co-maleic anhydride-acrylic acid) and poly(styrene-ethylene glycol). Notably, the topography and pores size of the PMER could be controlled by phase-separation and a pH-responsive “hairy” brush. For evaluating the enzymolysis efficiency of d -amino acid oxidase (DAAO) immobilized carrier (DAAO@PMER), a chiral ligand exchange capillary electrophoresis method was developed with d -methionine as the substrate. The DAAO@PMER showed good reusability and stability after five continuous runs. Notably, comparing with free DAAO in solution, the DAAO@PMER exhibited a 17.7-folds increase in catalytic velocity, which was attributed to its tailorable topography and pH-responsive property. The poly(acrylic acid) moiety of poly(styrene-co-maleic anhydride-acrylic acid) as the pH-responsive “hairy” brush generated topography changing domains upon adjusting the buffer pH, which enable the enzymolysis efficiency of DAAO@PMER to be tuned based upon the well-defined architectures of the PMER. This approach demonstrated that the topographical changes formed by phase-separation and the pH-responsive “hairy” brush indeed made the proposed porous polymer membrane as suitable supports for enzyme immobilization and fitting for enzymolysis applications, achieving high catalytic performance.

Swelling is one of the distinct properties and a significant parameter in the characterization of the crosslinked hydrogels. Swelling investigation at different temperatures was conducted for the produced hydrogel of chitosan grafted acrylamide/acrylic acid. Peleg’s model is a two parameters model, which can be used to describe the absorption of water or swelling. The data show that the swelling degree increases with temperature until it reaches 60°C, after which it decreases as the temperature rises higher. At RT, 30, 40, 60, and 80 °C, the swelling degree values of 1.4, 1.5,1.4, 2.3 and 0.7 g water/g dry hydrogel were observed after 8 hours. The applied models provided a good agreement with the experimental data with high values of the coefficient of determination (𝑅2). The observed F values and the standard error indicate the validity of the proposed model to describe the swelling of hydrogel at different temperatures. The swelling rate and swelling degree can be expressed using a 4th degree polynomial. It was concluded that the exponential association equation model represents swelling characteristics better than the others.

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.

This study aimed to synthesize a silver nanocomposite hydrogel based on poly (acrylic acid) and poly (vinyl pyrrolidone) grafted onto salep biopolymer and its use in controlled drug release. Drug release is one of the medicine goals that have been happening in the different methods, such as injections, pills or sprays. The useful drug dose, has measured by the drug concentration in the blood system, in the specific time. Researches have shown, in above methods, at the first time there is a high concentration of drug in the blood and by passing the time, this concentration decreases, so for achieve the useful drug dose, more drug is needed which it usually causes the increasing of the drug side effects. Thus for preventing these side effects, controlled drug release is investigated in this research. To identify the synthesized hydrogel, Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermometric gravimetric analysis (TGA) were used. The results showed that the release of deferasirox from the silver nanocomposite hydrogel network is related to the pH of the environment. In addition, the biodegradability and biocompatibility of this system have led to its use in the pharmaceutical industry.

Sorption of U (VI) onto novel nano material of amine functionalized poly acrylate hydrogel/nano silica was investigated. In the preparation, tri octyl amine, cyclohexane, poly acrylic acid oleic ac...