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Despite the potential use of polyelectrolyte multilayers for biomedical, separation, and energy applications, their dynamic properties are not sufficiently understood. In this work, center-of-mass diffusion of a weak polyacid—poly(methacrylic acid) (PMAA) of linear and 8-arm architecture (L-PMAA and 8-PMAA, respectively) and matched molecular weight—was studied in layer-by-layer (LbL) assemblies with poly(diallyldimethylammonium) chloride (PDADMAC) of varied molecular weight. The film deposition at low-salt, acidic conditions when PMAA was only partially ionized yielded thicker, more diffused layers with shorter PDADMAC chains, and bilayer thickness decreased for multilayers constructed with longer PDADMAC. The molecular architecture of PMAA had a weak effect on film growth, with bilayer thickness being ∼20% larger for L-PMAA for the films constructed with the shortest PDADMAC (35 kDa) and identical film growth for L-PMAA and 8-PMAA with the longest PDADMAC (300 kDa). The exposure of the multilayer films to 0.2M NaCl triggered a reduction in PMAA ionization and significant lateral diffusivity of fluorescently labeled PMAA molecules (PMAA*), with diffusion coefficients D ranging from 10−13 to 10−12 cm2/s, as determined by the fluorescence recovery after photobleaching technique. For all the films, polymer mobility was higher for star polyacids as compared to their linear counterparts, and the dependence of PMAA diffusion coefficient D on PDADMAC molecular weight (D ∼ M−n) was relatively weak (n < 0.6). However, 8-PMAA demonstrated an approximately doubled power exponent compared to the L-PMAA chains, suggesting a stronger effect of the molecular connectivity of the partner polycation molecules on the diffusion of star polyelectrolytes. [ABSTRACT FROM AUTHOR]

Herein, a novel strategy is presented for the photoinduced decarboxylative and dehydrogenative cross-coupling of a wide range of α-fluoroacrylic acids with hydrogermanes. This methodology provides an efficient and robust approach for producing various germylated monofluoroalkenes with excellent stereoselectivity within a brief photoirradiation period. The feasibility of this reaction has been demonstrated through gram-scale reaction, conversion of germylated monofluoroalkenes, and modification of complex organic molecules. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DES) exhibit comparable thermal and chemical stability to ionic liquids, coupled with excellent ionic conductivity. Moreover, they boast a higher degree of safety owing to lower toxicity and increased accessibility. Hence, the utilization of DES in gel preparation emerges as an effective solution to address the challenges associated with the inadequate stability of traditional hydrogels and the heightened toxicity of gels composed of ionic liquids. In this paper, eutectogels with excellent low-temperature sensing properties were prepared by using methacrylic acid (MAA) and pyrrole (Py) as monomers and DES as solvent. The eutectogel exhibits excellent sensing capability, with a gauge factor reaching 5.21. Additionally, DES prepared using choline chloride and urea endows the eutectogel with good freeze resistance, enabling sensing at −20 °C while maintaining stability. Moreover, the eutectogel accurately monitors changes in environmental temperature, providing a promising material for temperature-measuring flexible wearable sensor applications. [ABSTRACT FROM AUTHOR]

Abstract3-hydroxy-3-(3′-hydroxyphenyl)propanoic acid (CID: 102959) (3,3’-HPHPA) is one of several phenolic molecules that are generated by a process involving gut microbiota and have been implicated in autism and schizophrenia. The structural isomers of 3,3′-HPHPA have been challenging to separate chromatographically. Accordingly, their distribution across brain and other compartments in humans and experimental animals remains poorly characterized. We describe a modified liquid chromatography mass spectroscopy method for the detection and separation of seven commercially available structural isomers of 3,3′-HPHPA. We used the method to screen different compartments in the mouse and demonstrate its utility in identifying multiple structural isomers and conjugates of 3,3′-HPHPA in biological matrices. Characterizing the diversity and complexity of this family of structural isomers will advance studies of their bioactivity and clinical relevance. [ABSTRACT FROM AUTHOR]

Polymer composites offer numerous benefits, including low cost, easy processability, and diverse applications. In this work, we fabricated a composite material with high thermal conductivity and electromagnetic interference (EMI) shielding performance using EGaIn, a liquid metal (referred to as LM in this paper), MXene (MX), and expanded graphite (EG) as multifunctional fillers, along with polyacrylic acid (PAA). LM was used to exfoliate MX under the effect of shear force, which not only reduced the size of MX but also increased the aspect ratio of the 2D‐structured MX. MX was filled into the pores of EG to make a heat transfer path, thereby enhancing its thermal conductivity, mechanical properties, and EMI SE properties. LM served as the initiator of free‐radical polymerization to convert acrylic acid (AA) into PAA. Finally, the LMMX/EG/PAA composite was hot‐pressed to make the heat‐transfer path dense. As a result, the LMMX/EG/PAA composite exhibited a thermal conductivity of 1.88 W/m·K and an EMI shielding effect of 52 dB. [ABSTRACT FROM AUTHOR]

Achieving highly efficient self‐powered fibrous sensing systems is desirable for smart electronic textiles but remains a great challenge. Here, a bifunctional hydrogel is proposed by introducing of polyacrylic acid grafted MXene (MXene‐g‐PAA) into polyacrylamide/chitosan, achieving high‐sensitivity sensor and a stable hydrogel electrolyte of battery. The MXene‐g‐PAA flakes act as ion transport "highway", significantly enhance ionic conductivity, thereby increasing the sensitivity of sensors and facilitating Zn2+ diffusion in Zn‐ion battery (ZIB). The rich hydrogen bonding network in the hydrogel improves its mechanical properties and limits water molecule movement, thus reducing side reactions and prolonging the stability of ZIB. As a result, the fibrous sensor exhibits high strain sensitivity (gauge factor of 2.4) with a wide detection range (0–800%), and the fibrous Zn‐ion battery exhibits high capacity (353 mAh cm−3) with long cycling stability (400 cycles). The hydrogel‐based sensor and ZIB can be easily integrated into a flexible self‐powered sensing system, which effectively detects human movement and 3D ball motion. The bifunctional hydrogel with the integrated fibrous system will shed light on the development of next‐generation smart electronic textiles. [ABSTRACT FROM AUTHOR]

We formed core–shell‐like polyelectrolyte complexes (PECs) from an anionic bottlebrush polymer with poly (acrylic acid) side chains with a cationic linear poly (allylamine hydrochloride). By varying the pH, the number of side chains of the polyanionic BB polymers (Nbb), the charge density of the polyelectrolytes, and the salt concentration, the phase separation behavior and salt resistance of the complexes could be tuned by the conformation of the BBs. By combining the linear/bottlebrush polyelectrolyte complexation with all‐liquid 3D printing, flow‐through tubular constructs were produced that showed selective transport across the PEC membrane comprising the walls of the tubules. These tubular constructs afford a new platform for flow‐through delivery systems. [ABSTRACT FROM AUTHOR]

We formed core–shell‐like polyelectrolyte complexes (PECs) from an anionic bottlebrush polymer with poly (acrylic acid) side chains with a cationic linear poly (allylamine hydrochloride). By varying the pH, the number of side chains of the polyanionic BB polymers (Nbb), the charge density of the polyelectrolytes, and the salt concentration, the phase separation behavior and salt resistance of the complexes could be tuned by the conformation of the BBs. By combining the linear/bottlebrush polyelectrolyte complexation with all‐liquid 3D printing, flow‐through tubular constructs were produced that showed selective transport across the PEC membrane comprising the walls of the tubules. These tubular constructs afford a new platform for flow‐through delivery systems. [ABSTRACT FROM AUTHOR]

Haemonchus contortus is a blood-feeding gastrointestinal parasite that impacts grazing sheep, causing economic losses in animal production. Due to its anthelmintic resistance, alternative antiparasitic treatments like plant-based anthelmintics are necessary to explore. Artemisia cina (Asteraceae) is a plant whose n-hexane extract and ethyl acetate extract exhibit anthelmintic activity against H. contortus, the n-hexane more active. To discover additional bioactive metabolites, a chemical analysis was performed on ethyl acetate extract, which presented an LC90 of 3.30 mg/mL and allowed the isolation of 11-[(1R,5S,7R,8R,10S,)-1,8-dihydroxy-5,10-dimethyl-4-oxodecahydroazulen-7-yl] acrylic acid. This new sesquiterpene was identified through one and two-dimensional NMR. The compound was named cinic acid and displayed an LC50 of 0.13 (0.11–0.14) mg/mL and LC90 of 0.40 (0.37–0.44) mg/mL, which, compared with ethyl acetate extract larvicidal activity, was 256-fold more active at LC50 and 15.71-fold at LC90. In this study, a new sesquiterpene with larvicidal activity against H. contortus L3 infective larvae was isolated from the ethyl acetate extract of Artemisia cina. [ABSTRACT FROM AUTHOR]

We study the hyperactivation of α‐chymotrypsin (α‐ChT) using the acrylate polymer poly(2‐carboxyethyl) acrylate (PCEA) in comparison to the commonly used poly(acrylic acid) (PAA). The polymers are added during the enzymatic cleavage reaction of the substrate N‐glycyl‐L‐phenylalanine p‐nitroanilide (GPNA). Enzyme activity assays reveal a pronounced enzyme hyperactivation capacity of PCEA, which reaches up to 950 % activity enhancement, and is significantly enhanced to PAA (revealing an activity enhancement of approx. 450 %). In a combined experimental and computational study, we investigate α‐ChT/polymer interactions to elucidate the hyperactivation mechanism of the enzyme. Isothermal titration calorimetry reveals a pronounced complexation between the polymer and the enzyme. Docking simulations reveal that binding of polymers significantly improves the binding affinity of GPNA to α‐ChT. Notably, a higher binding affinity is found for the α‐ChT/PCEA compared to the α‐ChT/PAA complex. Further molecular dynamics (MD) simulations reveal changes in the size of the active site in the enzyme/polymer complexes, with PCEA inducing a more pronounced alteration compared to PAA, facilitating an easier access for the substrate to the active site of α‐ChT. [ABSTRACT FROM AUTHOR]

Stanozolol, a synthetic derivative of testosterone, is one of the common doping drugs among athletes and bodybuilders. It is metabolized to a large extent and metabolites are detected in urine for a longer duration than the parent compound. In this study, a novel dummy molecularly imprinted polymer (DMIP) is developed as a sorbent for solid-phase extraction of stanozolol metabolites from spiked human urine samples. The optimized DMIP is composed of stanozolol as the dummy template, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as the cross-linker in a ratio of 1:10:80. The extracted analytes were quantitively determined using a newly developed and validated ultrahigh-performance liquid chromatography tandem mass spectrometry method, where the limits of detection and quantitation were 0.91 and 1.81 ng mL−1, respectively, fulfilling the minimum required performance limit decided on by the World Anti-Doping Agency. The mean percentage extraction recoveries for 3'-hydroxystanozolol, 4β-hydroxystanozolol, and 16β-hydroxystanozolol are 97.80% ± 13.80, 83.16% ± 7.50, and 69.98% ± 2.02, respectively. As such, the developed DMISPE can serve as an efficient cost-effective tool for doping and regulatory agencies for simultaneous clean-up of the stanozolol metabolites prior to their quantification. [ABSTRACT FROM AUTHOR]

In this work, a nanogold surface molecularly imprinted polymer spectral probe (AuNP@MIP) for selectively identifying ferrocyanide was prepared under microwave irradiation using nanogold as the core, ferrocyanide as the template ion, methacrylic acid as the monomer, and ethylene glycol dimethacrylate as the cross-linking agent. AuNP@MIP was found to produce a resonance Rayleigh scattering (RRS) peak at 370 nm. When potassium ferrocyanide (K4Fe(CN)6) was present, a AuNP@MIP-Fe(CN)6 complex was formed, producing RRSenergy transfer (RRS-ET). With an increase in ferrocyanide concentration within a certain range, the RRS intensity at 370 nm decreased linearly, and the detection range was 0.02-0.40 µmol L-1, with a detection limit as low as 0.006 µmol L-1 ferrocyanide. This new method has the advantages of simplicity, rapidity, and selectivity when applied for the determination of K4Fe(CN)6 in table salt. [ABSTRACT FROM AUTHOR]

This article presents the development of a distance-based thread analytical device (dTAD) integrated with an ion-imprinted polymer (IIP) for quantitative monitoring of zinc ions (Zn2+) in human urine samples. The IIP was easily chemically modified onto the thread channel using dithizone (DTZ) as a ligand to bind to Zn2+ with methacrylic acid (MAA) as a functional monomer and ethylene glycol dimethacrylate (EGDMA) as well as 2,2-azobisisobutyronitrile (AIBN) as cross-linking agents to enhance the selectivity for Zn2+ detection. The imprinted polymer was characterized using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy and Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS). Under optimization, the linear detection range was from 1.0 to 20.0 mg L-1 (R2 = 0.9992) with a limit of detection (LOD) of 1.0 mg L-1. Other potentially interfering metal ions and molecules did not interfere with this approach, leading to high selectivity. Furthermore, our technique exhibits a remarkable recovery ranging from 100.48% to 103.16%, with the highest relative standard deviation (% RSD) of 5.44% for monitoring Zn2+ in human control urine samples, indicating high accuracy and precision. Similarly, there is no significant statistical difference between the results obtained using our method and standards on zinc supplement sample labels. The proposed method offers several advantages in detecting trace Zn2+ for point-of-care (POC) medical diagnostics and environmental sample analysis, such as ease of use, instrument-free readout, and cost efficiency. Overall, our developed dTADbased IIP method holds potential for simple, affordable, and rapid detection of Zn2+ levels and can be applied to other metal ions' analysis. [ABSTRACT FROM AUTHOR]

Despite recent advances in colloidal hydrogels, designing general and robust strategies that enable the controlled fabrication of colloidal hydrogels with strong mechanical properties still proves challenging. Herein, the statistical copolymerization‐induced self‐assembly (stat‐PISA) of monomers with hydrogen bonding ability is developed as a general strategy for colloidal hydrogels with high stretchability, anti‐swelling, and self‐healing abilities. This concept is first verified by the statistical dispersion copolymerization of acrylic acid and diacetone acrylamide, yielding statistical copolymer colloidal particles that further coalesced into a 3D colloidal network due to the hydrogen bonding interactions and hydrophobic microdomains on the colloidal surface. Both the microstructure and the mechanical properties of the colloidal hydrogels can be readily regulated by varying the stat‐PISA formulation. Besides, the colloidal hydrogel is developed as a selective dye adsorbent, with excellent selectivity for positively charged dyes. Due to its anti‐swelling property, the colloidal hydrogel is evaluated as a flexible strain sensor for motion detection underwater. The broad feasibility of this strategy is demonstrated by three additional stat‐PISA formulations, which all yielded colloidal hydrogels with good mechanical properties. This strategy is anticipated to inspire the design of colloidal hydrogels with robust mechanics and tailor‐made functionality, and broaden the potential applications of colloidal hydrogels. [ABSTRACT FROM AUTHOR]

Cancer immunotherapy using antigen-pulsed dendritic cells can induce strong cellular immune responses by priming cytotoxic T lymphocytes. In this study, we pulsed tumor cell lysates with VP-R8, a cell-penetrating D-octaarginine-linked co-polymer of N-vinylacetamide and acrylic acid (PNVA-co-AA), into the DC2.4 murine dendritic cell line to improve antigen uptake and then determined the anti-tumor effect in tumor-bearing mice. DC2.4 cells were pulsed with the cell lysate of EL4, a murine lymphoma cell line, and VP-R8 to generate the DC2.4 vaccine. For the in vivo study, DC2.4 cells pulsed with EL4 lysate and VP-R8 were subcutaneously injected into the inguinal lymph node to investigate the anti-tumor effect against EL4 and EL4-specific T cell immune responses. VP-R8 significantly improved antigen uptake into DC2.4 compared to conventional keyhole limpet hemocyanin (p < 0.05). The expression of MHC class I, MHC class II, and CD86 in DC2.4 cells significantly increased after pulsing tumor lysates with VP-R8 compared to other treatments (p < 0.05). The intra-lymph node injection of DC2.4 pulsed with both VP-R8 and EL4 lysate significantly decreased tumor growth compared to DC2.4 pulsed with KLH and lysates (p < 0.05) and induced tumor-infiltrating CD8T cells. The DC2.4 vaccine also remarkably increased the population of IFN-gamma-producing T cells and CTL activity against EL4 cells. In conclusion, we demonstrated that VP-R8 markedly enhances the efficiency of dendritic cell-based vaccines in priming robust anti-tumor immunity, suggesting its potential as a beneficial additive for dendritic cell-based immunotherapy. [ABSTRACT FROM AUTHOR]

Diabetes is a common disease that seriously endangers human health. Continuous glucose monitoring (CGM) is important for the prevention and treatment of diabetes. Glucose-sensing photonic nanochains (PNCs) have the advantages of naked-eye colorimetric readouts, short response time and noninvasive detection of diabetes, showing immense potential in CGM systems. However, the developed PNCs cannot disperse in physiological environment at the pH of 7.4 because of their poor hydrophilicity. In this study, we report a new kind of PNCs that can continuously and reversibly detect the concentration of glucose (Cg) in physiological environment at the pH of 7.4. Polyacrylic acid (PAA) added to the preparation of PNCs forms hydrogen bonds with polyvinylpyrrolidone (PVP) in Fe3O4@PVP colloidal nanoparticles and the hydrophilic monomer N-2-hydroxyethyl acrylamide (HEAAm), which increases the content of PHEAAm in the polymer shell of prepared PNCs. Moreover, 4-(2-acrylamidoethylcarbamoyl)-3-fluorophenylboronic acid (AFPBA), with a relatively low pKa value, is used as the glucose-sensing monomer to further improve the hydrophilicity and glucose-sensing performances of PNCs. The obtained Fe3O4@(PVP-PAA)@poly(AFPBA-co-HEAAm) PNCs disperse in artificial serum and change color from yellow-green to red when Cg increases from 3.9 mM to 11.4 mM, showing application potential for straightforward CGM. [ABSTRACT FROM AUTHOR]

The following paper presents a study of water dispersion obtained by emulsion co-polymerization of acrylic, methacrylic and vinyl monomers with the use of surfactants. Water dispersions of copolymers used in the production of paints intended for painting surfaces of steel metals and aluminum and its alloys were selected. They were synthesized by ethyl acrylate, butyl acrylate, acrylic acid, methyl methacrylate, methacrylic acid, acrylic acid amide, 2-hydroxyethylacrylate, glycidyl methacrylate, vinyl acetate and 1-ethyl-1-ethylpropylcarbamate (VeoVa 10). The investigated dispersion properties were considered in three groups. It turned out that the dispersions in which the copolymer had the lowest crystallinity temperature and were built of units having hydroxyl, carboxyl or amide groups were characterized by the most favorable properties. The hardness and weight of the membranes changed the least in the case of copolymers consisting of many units with functional groups. [ABSTRACT FROM AUTHOR]

In this work, the bio-silica and a novel thermoplastic were applied to improve the impact strength and thermal stability of epoxy resin. The ternary nanocomposites based on epoxy resin, bio-silica, and vinyl copolymer thermoplastic were fabricated at room temperature using a steel mold. The bio-silica was produced from rice husk biomass by calcination processing. The vinyl copolymer thermoplastic was synthesized from acrylic acid and hydroxyethyl acrylate via a radical polymerization, and assigned as poly(AA-co-HEA). The reinforcements have shown their vital role in improving impact strength, tensile strength, and glass transition temperature. Especially, by co-use of 1 wt% of silica and 5 wt% of poly(AA-co-HEA), the nanocomposite exhibited its highest tensile strength and resin impact strength. The thermal aging of nanocomposite was also investigated in detail. [ABSTRACT FROM AUTHOR]

Incorporating support structures into solid–liquid phase change materials (SLPCMs) addresses fluid dynamics challenges during phase transitions, albeit at the cost of reduced phase change enthalpy. We propose a novel approach for developing self-sustaining, porous phase change materials. This process begins with the fabrication of self-sustaining poly(acrylic acid) octadecyl ester aerogels through cross-linking polymerization and thermally induced phase separation (TIPS) followed by ambient drying to shape the aerogel. This aerogel demonstrates exceptional energy storage capacity, impressive room-temperature elasticity, and significant load-bearing strength. Leveraging this aerogel as a scaffold, we employ a 'one-step' technique to produce phase change gels (PCGs). This method, in which EI functions both as a solvent and as SLPCMs, yields PCGs with a high latent heat capacity of 192 J g−1, outstanding phase change elasticity, and structural stability, proving highly effective in photoelectric thermal management. Notably, the 'one-step' process for fabricating self-supporting PCGs circumvents conventional steps like solvent extraction and phase change material absorption in traditional porous foam production. This simplification streamlines manufacturing and facilitates the large-scale production of phase change materials that are morphologically stable, possess high latent heat, and exhibit superior mechanical properties. [ABSTRACT FROM AUTHOR]

Using polyaspartic acid (PAsp) and bentonite (BT) as the main raw materials, a new type of degradable soil water retaining agent (PAsp-AA/BT) was synthesized by microwave radiation. The optimum synthesis conditions and comprehensive properties of PAsp-AA/BT were discussed and the structure and surface characteristics of PAspsp-AA/BT were characterized by FTIR, SEM, XRD and TGA in the paper. The results showed that the optimum synthesis conditions of PAsp-AA/BT were as follows: the dosages of polyaspartic acid (PAsp), bentonite (BT), initiator potassium persulfate, crosslinking agent N,N′-methylene bisacrylamide was 5, 3, 0.3, 0.03%, respectively, the neutralization degree of acrylic acid was 75%, and the microwave power was 490W. Under this condition, the absorption ratio of the synthesized PAspsp-AA/BT in deionized water and 0.9% NaCl solution was 953 and 164 g/g, respectively. The synthesized PAsp-AA/BT had a high water absorption rate, good water retention and repeated water absorption, and the degradation rate in soil within 30 days reached 32.75%, with good degradation effect. The analysis of SEM, FT-IR, XRD and TGA showed that: the surface of PAsp-AA/BT was rough and had obvious pore structure, which was conducive to the diffusion of water molecules; polyaspartic acid, bentonite and acrylic acid were polymerized; the cross-linking structure was formed between polyaspartic acid, bentonite and acrylic acid; the product of PASP-AA/BT had good thermal stability. This study provides a new soil water retaining agent, which is helpful for the better development of soil water retaining agent research. [ABSTRACT FROM AUTHOR]

In the present work, we synthesized and tested a magnetic molecularly imprinted polymer (mag‐MIP) sensor for the detection of tetracycline in food samples. High‐performance liquid chromatography (HPLC) and spectrofluorometry were employed for tetracycline determination. The mag‐MIP was polymerized on the surface of Fe3O4@SiO2 magnetic nanoparticles using the following substances: 4 mmol of methacrylic acid as the functional monomer, 20 mmol of ethylene glycol dimethacrylate (EGDMA) as the cross‐linking agent, 82.5 mg of benzoyl peroxide as the radical initiator, and 30 ml of acetonitrile as the solvent. The physicochemical characteristics of the proposed mag‐MIP, including adsorption capabilities and selectivity, were studied and compared with those of a magnetic non‐molecularly imprinted polymer (mag‐NIP). The analytical curve was constructed in the range of 1.0×10−5–8.0×10−5 mol L−1, LOD: 3.3×10−6, LOQ: 1.1×10−5 mol L−1. The results obtained from the adsorption analysis showed that the highest adsorption capacity of the mag‐MIP at equilibrium was 8.247 mg g−1 and that the tetracycline adsorption process followed the Langmuir adsorption isotherm model and pseudo‐second‐order reaction kinetics. The proposed mag‐MIP also exhibited good results when subjected to fluorescence analysis; an increase in tetracycline concentration resulted in an increase in the adsorption capacity, and this led to the effective removal of tetracycline with the reduction of fluorescence intensity. The applicability of the proposed mag‐MIP was evaluated in honey, cow milk, and egg samples through recovery tests conducted using samples containing spiked tetracycline concentration at two different concentration levels (1.7×10−5 and 2.5×10−5 mol L−1), where we obtained recovery percentages in the range of 73.2–87.2 % (HPLC) and 90.5–103.7 % (spectrofluorometry). [ABSTRACT FROM AUTHOR]

Poly(methacrylamide‐co‐methacrylic acid) P(MAAm‐co‐MAAc) nanogels were synthesized using emulsion polymerization method and characterized in terms of structure, stimuli‐sensitive behavior and nanosize. The effect of monomer, surfactant (sodium dodecyl sulfate) and cross‐linker (N,N′‐methylenebisacrylamide) concentration on the nanosize of the nanogels was investigated. The hydrodynamic size of nanogels was determined by dynamic light scattering (DLS) and it was found to be in the range of 109.8–146.1 nm. Polydispersity index (PDI) values were lower than 0.3 (in the range of 0.145–0.261) confirming the narrow size distribution of the nanogels. Zeta potential measurements indicated that the nanogels exhibited good stability. Stimuli‐sensitive behavior of the nanogels was evaluated using UV‐visible spectroscopy. Characterization of the nanogels was carried out by Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), X‐ray diffraction (XRD) and scanning electron microscopy (SEM). [ABSTRACT FROM AUTHOR]

Background: Older adults presenting with dual-decline in cognition and walking speed face a 6-fold higher risk for dementia compared with those showing no decline. We hypothesized that the metabolomics profile of dual-decliners would be unique even before they show signs of decline in cognition and gait speed. Objective: The objective of this study was to determine if plasma metabolomics signatures can discriminate dual-decliners from no decliners, purely cognitive decliners, and purely motor decliners prior to decline. Methods: A retrospective cross-sectional study using baseline plasma for untargeted metabolomics analyses to investigate early signals of later dual-decline status in study participants (n = 76) with convenient sampling. Dual-decline was operationalized as decline in gait speed (>10 cm/s) and cognition (>2 points decline in Montreal Cognitive Assessment score) on at least two consecutive 6-monthly assessments. The participants' decliner status was evaluated 3 years after the blood sample was collected. Pair-wise comparison of detected compounds was completed using principal components and hierarchical clustering analyses. Results: Analyses did not detect any cluster separation in untargeted metabolomes across baseline groups. However, follow-up analyses of specific molecules detected 4 compounds (17-Hydroxy-12-(hydroxymethyl)-10-oxo-8 oxapentacyclomethyl hexopyranoside, Fleroxacin, Oleic acid, and 5xi-11,12-Dihydroxyabieta-8(14),9(11),12-trien-20-oic acid) were at significantly higher concentration among the dual-decliners compared to non-decliners. The pure cognitive decliner group had significantly lower concentration of six compounds (1,3-nonanediol acetate, 4-(2-carboxyethyl)-2-methoxyphenyl beta-D-glucopyranosiduronic acid, oleic acid, 2E-3-[4-(sulfo-oxy)phenyl] acrylic acid, palmitelaidic acid, and myristoleic acid) compared to the non-decliner group. Conclusions: The unique metabolomics profile of dual-decliners warrants follow-up metabolomics analysis. Results may point to modifiable pathways. [ABSTRACT FROM AUTHOR]

Epoxy acrylate is produced by esterifying epoxy resin and acrylic acid through a ring-opening reaction. This process is highly exothermic and can be challenging to control gel formation. The thermal hazards of epoxy acrylate preparation were evaluated in this study by investigating the ring-opening esterification reaction between acrylic acid (AA) and bisphenol A epoxy resin (E-51) catalyzed by triethylamine (TEA). The heat release during the reaction process was analyzed using a reaction calorimeter (RC1mx) to simulate industrial conditions. Increasing the TEA catalyst content from 0.3 to 1.0 mass% resulted in a significant rise in reaction conversion from 75.35 ± 0.10% to 98.44 ± 0.10%. Differential scanning calorimetry (DSC) and accelerating rate calorimeter (ARC) were used to examine the thermal runaway process during epoxy acrylate synthesis. Increasing the TEA content from 0.3 to 1.0 mass% decreased the initial reaction temperature from 60.16 ± 0.62 to 45.33 ± 0.40 °C and the critical temperature of side reactions from 153.71 ± 1.51 to 117.85 ± 1.19 °C. The severity of the runaway was classified as medium at process temperatures of 80–110 °C. This study highlights the importance of considering reaction conditions to prevent uncontrolled reactions during epoxy acrylate synthesis, providing valuable insights for industrial epoxy acrylate preparation. [ABSTRACT FROM AUTHOR]

The dilational modulus (E) of polymer films has been commonly measured using the oscillating ring/bubble/drop methods with an external force, and often without specifying the state of the adsorbed film. This study explores an approach where E was determined from the relaxations of surface tension (ST) and surface area (SA) of natural perturbations, in which ST and SA were monitored using a pendant bubble tensiometer. The E of the adsorbed film of PAA (polyacrylic acid) was evaluated for aqueous solutions at CPAA = 5 × 10−4 g/cm3, [MW = 5, 25, and 250 (kDa)]. The E (=dγ/dlnA) was estimated from the surface dilational rate (dlnA/dt) and the rate of ST change (dγ/dt) of the bubble surface from the natural perturbation caused by minute variations in ambient temperature. The data revealed that (i) a considerable time is required to reach the equilibrium-ST (γeq) and to attain the saturated dilational modulus (Esat) of the adsorbed PAA film, (ii) both γeq and Esat of PAA solutions increase with MW of PAA, (iii) a lower MW solution requires a longer time to reach its γeq and Esat, and (iv) this approach is workable for evaluating the E of adsorbed polymer films. [ABSTRACT FROM AUTHOR]

This manuscript serves as the starting point for in-depth research of multicomponent, statistical, methacrylate-based copolymers that potentially mimic the behavior of proteins in aqueous solutions. These synthetic macromolecules are composed of specially chosen comonomers: methacrylic acid (MAA), oligoethylene glycol methyl ether methacrylate (OEGMA475), 2-(dimethylamino)ethyl methacrylate (DMAEMA) and benzyl methacrylate (BzMA). Monomer choice was based on factors such as the chemical nature of pendant functional groups, the polyelectrolyte/polyampholyte and amphiphilic character and the overall hydrophobic–hydrophilic balance (HLB) of the obtained quaterpolymers. Their synthesis was achieved via a one-pot reversible addition fragmentation chain transfer (RAFT) polymerization in two distinct compositions and molecular architectures, linear and hyperbranched, respectively, in order to explore the effects of macromolecular topology. The resulting statistical quaterpolymers were characterized via 1H-NMR and ATR-FTIR spectroscopies. Their behavior in aqueous solutions was studied by dynamic (DLS) and electrophoretic light scattering (ELS) and fluorescence spectroscopy (FS), producing vital information concerning their self-assembly and the structure of the formed aggregates. The physicochemical studies were extended by tuning parameters such as the solution pH and ionic strength. Finally, the quaterpolymer behavior in FBS/PBS solutions was investigated to test their colloid stability and biocompatibility in an in vivo-mimicking, biological fluid environment. [ABSTRACT FROM AUTHOR]

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

Advancing a metal‐free room temperature phosphorescent (RTP) material that exhibits multicolor emission, remarkable RTP lifetime, and high quantum yield still faces the challenge of achieving intersystem crossing between singly and triplet excited states, as well as the rapid decay of triplet excited states due to nonradiative losses. In this study, a novel strategy is proposed to address these limitations by incorporating o‐phenylenediamine, which generates multiple luminescent centers, and long‐chain polyacrylic acid to synthesize carbonized polymer dots (CPDs). These CPDs are then embedded in a rigid B2O3 matrix, effectively limiting nonradiative losses through the synergistic effects of polymer cross‐linking and the rigid matrix. The resulting CPD‐based materials exhibit remarkable ultralong phosphorescence in shades of blue and lime green, with a visible lifetime of up to 49 s and a high phosphorescence quantum yield. Simultaneously, this study demonstrates the practical applicability of these excellent material properties in anti‐counterfeiting and information encryption. [ABSTRACT FROM AUTHOR]

Recent work has demonstrated that temporary crosslinks in polymer networks generated by chemical "fuels" afford materials with large, transient changes in their mechanical properties. This can be accomplished in carboxylic‐acid‐functionalized polymer hydrogels using carbodiimides, which generate anhydride crosslinks with lifetimes on the order of minutes to hours. Here, the impact of the polymer network architecture on the mechanical properties of transiently crosslinked materials was explored. Single networks (SNs) were compared to interpenetrated networks (IPNs). Notably, semi‐IPN precursors that give IPNs on treatment with carbodiimide give much higher fracture energies (i.e., resistance to fracture) and superior resistance to compressive strain compared to other network architectures. A precursor semi‐IPN material featuring acrylic acid in only the free polymer chains yields, on treatment with carbodiimide, an IPN with a fracture energy of 2400 J/m2, a fourfold increase compared to an analogous semi‐IPN precursor that yields a SN. This resistance to fracture enables the formation of macroscopic complex cut patterns, even at high strain, underscoring the pivotal role of polymer architecture in mechanical performance. [ABSTRACT FROM AUTHOR]

Recent work has demonstrated that temporary crosslinks in polymer networks generated by chemical "fuels" afford materials with large, transient changes in their mechanical properties. This can be accomplished in carboxylic‐acid‐functionalized polymer hydrogels using carbodiimides, which generate anhydride crosslinks with lifetimes on the order of minutes to hours. Here, the impact of the polymer network architecture on the mechanical properties of transiently crosslinked materials was explored. Single networks (SNs) were compared to interpenetrated networks (IPNs). Notably, semi‐IPN precursors that give IPNs on treatment with carbodiimide give much higher fracture energies (i.e., resistance to fracture) and superior resistance to compressive strain compared to other network architectures. A precursor semi‐IPN material featuring acrylic acid in only the free polymer chains yields, on treatment with carbodiimide, an IPN with a fracture energy of 2400 J/m2, a fourfold increase compared to an analogous semi‐IPN precursor that yields a SN. This resistance to fracture enables the formation of macroscopic complex cut patterns, even at high strain, underscoring the pivotal role of polymer architecture in mechanical performance. [ABSTRACT FROM AUTHOR]

Atmospheric moisture is a valuable resource for fresh water and potentially sustainable energy. However, direct harvesting water from moisture (the vapor form) remains the most challenging. Hybrid desiccants made from hydrogels embedded with salt offer promise in absorbing moisture. However, the desorption process often requires additional energy to heat the samples. Here, poly(acrylic acid) (PAA) hydrogels embedded with lithium chloride are prepared, demonstratng simultaneous moisture absorption and self‐release of liquid water at room temperature with 50–90% relative humidity. The water self‐releasing process can be separated into two distinct stages: 1) surface release, where water droplets grow on the hydrogel surface due to differences in nucleation and diffusion rates, and 2) bulk release, triggered by the collapse of polymer chains, subsequently releasing water from the hydrogel network. Factors such as salt concentration, hydrogel crosslinking density, and film thickness are investigated to better understand the moisture absorption and water‐releasing processes. Moreover, hydrophobic domains are introduced onto the salt‐embedded PAA films, creating an edge effect that enhances the droplet growth rates. When the hydrophobic domains are patterned, the movement of released water can be guided, resulting in a threefold increase in water removal rate attributed to gravitational force. [ABSTRACT FROM AUTHOR]

The experimental preparation of polyacrylic acid by free radical polymerization is an important and classic teaching content in the course of Polymer Chemistry Experiments. The monomer is easy to obtain and the reaction conditions are mild. As a representative experiment to master the free radical polymerization reaction and the preparation of porous adsorption materials, it is offered in many colleges and universities. However, in the preparation experiments of polyacrylic acid in existing textbooks, the reaction system is easy to gelate and produces more waste liquid. The process took 30.5 to 33 hours and could not be completed within one teaching session. The characterization process is complicated. Therefore, natural and cheap sodium alginate was used as thickener in this improved experiment to stabilize the viscosity of the reaction system and prevent the gelation of the reaction system caused by the sharp increase of local viscosity. Using the same natural and cheap porous diatomite as filler, the porous resin was prepared by co-precipitation with the polyacrylic acid solution prepared by free radical polymerization reaction, which greatly reduced the use and consumption of organic solvents. In addition, this improved experiment follows the academic frontier, and introduces the smartphone identification-colorimetric analysis to characterize the adsorption performance of the product, which is fast and convenient. The new method of hole formation and representation reduced the duration of the experiment to 5 hours, ensuring the continuity of teaching, while retaining the characteristics of the original experiment, making the experiment more meaningful and conducive to stimulate students' interest in learning this experimental course. [ABSTRACT FROM AUTHOR]

A novel N,N methylene-bis-acrylamide (MBA) crosslinked tamarind gum and β-cyclodextrin graft-poly(methacrylic acid) (TG/β-CG-g-MAA) hydrogel was formulated for colon targeting. The swelling capability, mechanical strength, sol–gel fraction (%), in vitro release and in vivo toxicological screening were estimated experimentally. The effect of polymers, monomer and crosslinker on percentage drug loading, swelling and drug release was determined. TG/β-CD-g-MAA hydrogel was characterized by FTIR, thermal analysis, X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). Swelling was significant at pH 7.4 as compared to pH 1.2. Drug release studies showed that release was significant at pH 7.4 as compared to pH 1.2. Developed hydrogels were porous, thermally stable, offered uniform distribution of amorphous drug and pH-dependent capecitabine release in controlled fashion. Kinetic modelling revealed zero-order drug release and Korsmeyer-Peppas model mechanism of release. Lastly, TG/β-CD-g-MAA hydrogel (F11) can act as prospective pH-responsive carrier for colon targeting. [ABSTRACT FROM AUTHOR]

Various derivatives of cinnamic acid have been reported to possess significant activities such as antioxidant and hepatoprotective, and neuroprotective activities. Interestingly, testicular toxicity has been linked to several causes, with oxidative damage being one of the pathophysiological mechanisms. 3-(4-methoxyphenyl) acrylic acid (1), a derivative of cinnamic acid, was synthesized and then investigated for its effects on iron-induced testicular injury and oxidative stress via ex vivo and in silico studies, respectively. Evaluations were done on KAD-1's FRAP, DPPH free radical scavenging activity, and iron chelating potential. Through the ex vivo incubation of tissue supernatant and 0.1 mM FeSO4 for 30 min at 37 °C with different concentration of 1, oxidative testicular damage treatments were induced. The scavenging property of 1 increases significantly (p < 0.05) as the concentration increases when compared with the standard quercetin. The MDA, CAT, ATPase, and ENTPDase activities were reduced when testicular damage was induced (p < 0.05). The group treated with 30 mg/mL had the highest level of MDA. A significant rise in GSH level and activity of SOD were observed. The result obtained indicated that 1 has the potential to prevent oxidative testicular toxicity, as evidenced by its capacity to control nucleotide hydrolysis and reduce oxidative stress. Overall, the results of this experimental study point to some possible uses of 3-(4-methoxyphenyl) acrylic acid (1) in the prevention of oxidative testicular dysfunction. Therefore, 3-(4-methoxyphenyl) acrylic acid (1) would be a good product in developing a medication to alleviate male infertility. [ABSTRACT FROM AUTHOR]

Undoubtedly, with the increasing awareness of the scientific community and the public, current trends are directing research to implement effective and combined yet nature friendly methodologies. Due to advantages such as adaptability and versatility, the combination of electrospinning and light is increasingly intriguing. This study proposes a new strategy for producing amphiphilic fibers from graft copolymer of polypropylene (PP) and poly (acrylic acid) (FPP-g-PAA). The first step includes the synthesis of copolymer comprising PP main chain possessing poly (tertiary butyl acrylate) pendant groups via photo-induced metal-free atom transfer radical polymerization (PIMF-ATRP) of tertiary butyl acrylate (t-BA) in the presence of perylene and chlorinated polypropylene (PP-Cl) as a macro photo-initiator (PP-g-PtBA). Then, FPP-g-PAA is prepared by acidolysis of t-BA units to acrylic acid moieties. In the second step, the PP-g-PAA is successful electrospun to fabricate the ultimate amphiphilic fibers. The chemical steps are monitored and confirmed by Fourier-transform infrared (FT-IR) and proton magnetic resonance (1H-NMR) spectroscopies, and gel permeation chromatography (GPC). Following the structural characterization, morphological and wetting properties are systematically determined with scanning electron microscopy (SEM) and water contact angle (WCA) measurement by depending on surface characteristics of the samples. Thermal behaviour of precursors and synthesized electrospun fibers has also been evaluated and compared by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The SEM images display that the achieved fibers were smooth and circular with the average diameters ranging from 3.3 μm up to 3.9 μm. After WCA measurements, it was elucidated that the hydrophobic nature of electrospun PP-g-PtBA was transformed into amphiphilic structure by hydrolysis of PtBA pendant groups. The reported approach is very encouraging and expected to trigger further development for scientists preparing various types of amphiphilic polyolefin fiber based materials. [ABSTRACT FROM AUTHOR]

Triazine pesticides can easily remain in the environment and food, causing serious harm to organisms. Developing a pretreatment technology with strong purification and enrichment capabilities is of great significance for the detection of triazine. In this paper, magnetic dual-template nanomolecular imprinted polymers (MMIPs) were synthesized using silica-modified Fe3O4 magnetic shell nanoparticles as carriers, methacrylic acid (MAA) as a functional monomer, and cyromazine and melamine as template molecules. This material was characterized by transmission electron microscope (TEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The adsorption experiments were carried out and the results showed that the MMIPs had the chemical properties of surface molecular imprinting. The binding constants of MMIPs were 26.95 mg/L and 657.89 mg/L, and their maximum apparent binding capacity was 2.02 mg/g and 8.59 mg/g, respectively. The prepared MMIPs were used as adsorbents for dispersive solid phase extraction, and high-performance liquid chromatography analysis was coupled to determine triazine pesticides from three samples. The recovery of this method was between 84.8% and 109.5% and the limits of detection were between 0.01–0.03 µg/L. This method greatly shortens the sample pretreatment time and achieves the purpose of rapid pretreatment. [ABSTRACT FROM AUTHOR]

Levodopa (LD) has been the most efficacious medication and the gold standard therapy for Parkinson's disease (PD) for decades. However, its long-term administration is usually associated with motor complications, which are believed to be the result of the fluctuating pharmacokinetics of LD following oral administration. Duodopa® is the current option to offer a continuous delivery of LD and its decarboxylase inhibitor carbidopa (CD); however, its administration involves invasive surgical procedures, which could potentially lead to lifelong complications, such as infection. Recently, dissolving microarray patches (MAPs) have come to the fore as an alternative that can bypass the oral administration route in a minimally invasive way. This work explored the potential of using dissolving MAPs to deliver LD and CD across the skin. An acidic polymer poly(acrylic acid) (PAA) was used in the MAP fabrication to prevent the potential oxidation of LD at neutral pH. The drug contents of LD and CD in the formulated dissolving MAPs were 1.82 ± 0.24 and 0.47 ± 0.04 mg/patch, respectively. The in vivo pharmacokinetic study using female Sprague–Dawley® rats (Envigo RMS Holding Corp, Bicester, UK) demonstrated a simultaneous delivery of LD and CD and comparable AUC values between the dissolving MAPs and the oral LD/CD suspension. The relative bioavailability for the dissolving MAPs was calculated to be approximately 37.22%. Accordingly, this work highlights the use of dissolving MAPs as a minimally invasive approach which could potentially bypass the gastrointestinal pathway and deliver both drugs continuously without surgery. [ABSTRACT FROM AUTHOR]

The influence of apparent slip on oscillatory shear measurements of a viscoplastic microgel [0.6 wt. % of poly(acrylic acid)] is analyzed by Couette and parallel-plate rheometry and particle image velocimetry (Rheo-PIV). We first provide direct evidence of a critical shear stress for the onset of slip of the microgel under oscillatory (σos) and nonoscillatory measurements (σs). Afterward, we describe the effect of slip on oscillatory measurements via waveforms, Bowditch–Lissajous curves, Fourier transform (FT) rheology, PIV, and as a sequence of physical processes (SPP). The effect of slip is mainly observed at low oscillating frequencies. For amplitudes of the oscillating stresses σ0 ≤ σos, the microgel exhibits linear viscoelastic behavior with in-phase strain response. For σos< σ0 ≤ yield stress (σy), slip introduces a phase shift in the strain response with a forward-tilted waveform and "mango" shape Bowditch–Lissajous curves. Meanwhile, FT rheology shows negligible even harmonics. The strain measured by the rheometer does not match the true strain determined by PIV in the presence of slip, resulting in waveforms that depend on how the displacement distribution is interpreted. This result indicates a break in the symmetry of the flow, that is, the microgel response no longer follows the imposed oscillation, which makes any attempt to correct oscillatory data for slip complex. This behavior arises from recoil of the slipping microgel after reaching its maximum displacement in a cycle. Finally, we provide an overall picture of the kinematics of the process of yielding in the presence of slip as an SPP. [ABSTRACT FROM AUTHOR]

Regenerative medicine is an interdisciplinary field aiming at restoring pathologically damaged tissues and whole organs by cell transplantation in combination with proper supporting scaffolds. Gelatine-based ones are very attractive due to their biocompatibility, rapid biodegradability, and lack of immunogenicity. Gelatine-based composite hydrogels, containing strengthening agents to improve their modest mechanical properties, have been demonstrated to act as extracellular matrices (ECMs), thus playing a critical role in "organ manufacturing". Inspired by the lysyl oxidase (LO)-mediated process of crosslinking, which occurs in nature to reinforce collagen, we have recently developed a versatile protocol to crosslink gelatine B (Gel B) in the presence or absence of LO, using properly synthesized polystyrene- and polyacrylic-based copolymers containing the amine or aldehyde groups needed for crosslinking reactions. Here, following the developed protocol with slight modifications, we have successfully crosslinked Gel B in different conditions, obtaining eight out of nine compounds in high yield (57–99%). The determined crosslinking degree percentage (CP%) evidenced a high CP% for compounds obtained in presence of LO and using the styrenic amine-containing (CP5/DMAA) and acrylic aldehyde-containing (CPMA/DMAA) copolymers as crosslinking agents. ATR-FTIR analyses confirmed the chemical structure of all compounds, while optical microscopy demonstrated cavernous, crater-like, and labyrinth-like morphologies and cavities with a size in the range 15–261 µm. An apparent density in the range 0.10–0.45 g/cm3 confirmed the aerogel-like structure of most samples. Although the best biodegradation profile was observed for the sample obtained using 10% CP5/DMAA (M3), high swelling and absorption properties, high porosity, and good biodegradation profiles were also observed for samples obtained using the 5–10% CP5/DMAA (M4, 5, 6) and 20% CPMA/DMAA (M9) copolymers. Collectively, in this work of synthesis and physicochemical characterization, new aerogel-like composites have been developed and, based on their characteristics, which fit well within the requirements for TE, five candidates (M3, M4, M5, M6, and M9) suitable for future biological experiments on cell adhesion, infiltration and proliferation, to confirm their effective functioning, have been identified. [ABSTRACT FROM AUTHOR]

The self-healing cement used in oil wells aims to provide long-term interlayer isolation by enabling the cement system to repair itself. This paper compared the absorption properties of 2-acrylamido-2-methyl propanesulfonic acid (AMPS)-based superabsorbent polymer (SAP) and acrylic acid (AA)-based SAP in water and cement slurry filtrate. The effect of cement slurry filtrate on the water absorption properties of the two SAPs was evaluated. The results showed that the calcium ions in the cement slurry would crosslink with the carboxyl groups in the AA-SAP, increasing the crosslink density and greatly reducing its absorption rate in water. Compared to AA-SAP, AMPS-SAP is more suitable for oil well cement slurries. AMPS-SAP can help reduce the fluid loss of cement slurry. The addition of 0.4% AMPS-SAP in cement slurry results in a 64 mL decrease in fluid loss. The properties (rheological properties, thickening time, and compressive strength) of cement slurry meet the requirements for well cementing construction. [ABSTRACT FROM AUTHOR]

Reppe carbonylation of acetylene is an atom-economic and non-petroleum approach to synthesize acrylic acid and acrylate esters, which are key intermediates in the textile, leather finishing, and polymer industries. In the present work, a noble metal-free Co@SiO2 catalyst was prepared and evaluated in the methoxycarbonylation reaction of acetylene. It was discovered that pretreatment of the catalyst by different reductants (i.e., C2H2, CO, H2, and syngas) greatly improved the catalytic activity, of which Co/SiO2-H2 demonstrated the best performance under conditions of 160 °C, 0.05 MPa C2H2, 4 MPa CO, and 1 h, affording a production rate of 4.38 gMA+MP gcat−1 h−1 for methyl acrylate (MA) and methyl propionate (MP) and 0.91 gDMS gcat−1 h−1 for dimethyl succinate (DMS), respectively. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and diffuse reflectance infrared Fourier transform spectra of CO adsorption (CO-DRIFTS) measurements revealed that an H2 reduction decreased the size of the Co nanoparticles and promoted the formation of hollow architectures, leading to an increase in the metal surface area and CO adsorption on the catalyst. The hot filtration experiment confirmed that Co2(CO)8 was generated in situ during the reaction or at the pre-activation stage, which served as the genuine active species. Our work provides a facile and convenient approach to the in situ synthetization of Co2(CO)8 for a Reppe carbonylation reaction. [ABSTRACT FROM AUTHOR]

Hydrogels based on sodium alginate (SA) and partially neutralised poly(acrylic acid) were obtained by radical polymerisation. The hydrogels were cross-linked with N,N′-methylenebisacrylamide (MBA), simultaneously grafting the resulting polymer onto SA. The findings of the FTIR spectroscopy showed that all of the hydrogels were effectively synthesized and sodium alginate was chemically bonded with the poly(sodium acrylate) matrix. DSC analysis of the melting heat and glass transition parameters indicated that the hydrogel structure had changed as a result of the cross-linking process. Sodium alginate and MBA were tested at different concentrations to determine how they affected the hydrogel properties. A very high content of the biopolymer, i.e., sodium alginate, was used in our research, up to 33 wt%. This resulted in durable and stable hydrogels with a very high ability to uptake water, comparable to hydrogels based on synthetic polymers only. The ability to swell is inversely proportional to the quantity of MBA present. By increasing the amount of sodium alginate in the hydrogel, the ability of the hydrogel to absorb water is reduced. However, water uptake remains relatively high at 350 g·g−1, even for the hydrogel with the highest SA content. [ABSTRACT FROM AUTHOR]

A novel cost-effective sensor material was developed from modified graphene oxide based molecular imprinted polymer (GO-MIP) for the detection of folic acid (FA). This GO-MIP was obtained through several processes including functionalization, polymerization and template molecule introduction/removal during the synthesizing process. Firstly, graphene oxide (GO) was prepared by modified Hummers method which undergoes hydroxyl functionalization to form GO–OH. It further undergoes surface modification with allyl bromide in presence of sodium hydroxide (NaOH) and dimethyl sulfoxide (DMSO) to form vinylated GO–OH (GO–O–CH=CH2). The GO–O–CH=CH2 subjected to further molecular imprinting process with methacrylic acid (MAA) as the monomer and ethylene glycol dimethacrylate (EGDMA) as the cross-linker, azobisisobutyronitrile (AIBN) as the initiator and FA as the template molecule. The different preparatory stages of materials were characterized by FTIR, XRD and SEM techniques to understand the formation. The obtained GO–MIP was used as an active material for FA sensing. The pH studies were carried out using cyclic voltameteric measurement and maximum current is obtained at pH 4.0. The proposed GO-MIP based electrode showed excellent electrocatalytic activity toward FA detection at optimized conditions. The limit of detection obtained in the present study is 1.0 nM. The results obtained from the real time usability of electrodes in wheat flour, tablet and spinach are well with commercially available FA monitors. The results endorse the promising application of GO-MIP toward superior FA sensing with long-term stability. Method of synthesis of GO-MIP [ABSTRACT FROM AUTHOR]

The application of calcium coacervates (CCs) may hold promise for dental hard tissue remineralization. The aim of this study was to evaluate the effect of the infiltration of artificial enamel lesions with a CC and its single components including polyacrylic acid (PAA) compared to that of the self-assembling peptide P11-4 in a pH-cycling (pHC) model. Enamel specimens were prepared from bovine incisors, partly varnished, and stored in demineralizing solution (DS; pH 4.95; 17 d) to create two enamel lesions per sample. The specimens were randomly allocated to six groups (n = 15). While one lesion per specimen served as the no-treatment control (NTC), another lesion (treatment, T) was etched (H3PO4, 5 s), air-dried and subsequently infiltrated for 10 min with either a CC (10 mg/mL PAA, 50 mM CaCl2 (Ca) and 1 M K2HPO4 (PO4)) (groups CC and CC + DS) or its components PAA, Ca or PO4. As a commercial control, the self-assembling peptide P11-4 (CurodontTM Repair, Credentis, Switzerland) was tested. The specimens were cut perpendicularly to the lesions, with half serving as the baseline (BL) while the other half was exposed to either a demineralization solution for 20 d (pH 4.95; group CC + DS) or pHC for 28 d (pH 4.95, 3 h; pH 7, 21 h; all five of the other groups). The difference in integrated mineral loss between the lesions at BL and after the DS or pHC, respectively, was analyzed using transversal microradiography (ΔΔZ = ΔZpHC − ΔZbaseline). Compared to the NTC, the mineral gain in the T group was significantly higher in the CC + DS, CC and PAA (p < 0.05, Wilcoxon). In all of the other groups, no significant differences between treated and untreated lesions were detected (p > 0.05). Infiltration with the CC and PAA resulted in a consistent mineral gain throughout the lesion body. The CC as well as its component PAA alone promoted the remineralization of artificial caries lesions in the tested pHC model. Infiltration with PAA further resulted in mineral gain in deeper areas of the lesion body. [ABSTRACT FROM AUTHOR]

In this study, a molecularly imprinted co-polymer-based electrochemical sensor has been fabricated that shows sensitive and selective detection of paracetamol. Molecularly imprinted co-polymer synthesis was achieved using methacrylic acid and styrene as functional monomers, azobisisobutyronitrile as a free radical initiator, ethylene glycol dimethacrylate as a cross-linker, and dimethyl sulfoxide as a porogenic solvent. The molecularly imprinted co-polymer was synthesized using a thermal free radical bulk polymerization technique. The molecularly imprinted co-polymer is characterized by Fourier-transform infrared spectroscopy. The LCR meter was used to measure electrical parameters such as inductance and resistance. The sensor response was linear and concentration-dependent. The lower limit of detection of the fabricated sensor in terms of inductance and resistance was 12 and 5.33 mg/L, respectively. Furthermore, in the presence of competing substances such as ascorbic acid and uric acid, the fabricated sensor proved a selective response. The fabricated sensor also shows reproducibility and reversible response. [ABSTRACT FROM AUTHOR]

Polyionic liquid hydrogels attract increasing attention due to their unique properties and potential applications. However, research on amino acid‐based polyionic liquid hydrogels is still in its infancy stage. Moreover, the effect of amino acid types on the properties of hydrogels is rarely studied to date. In this work, amino acid‐based polyionic liquid hydrogels (D/L‐PCAA hydrogels) are synthesized by copolymerizing vinyl choline–amino acid ionic liquids and acrylic acids using Al3+ as a crosslinking agent and bacterial cellulose (BC) as a reinforcing agent. The effects of amino acid types on mechanical and antimicrobial properties are systematically investigated. D‐arginine‐based hydrogel (D‐PCArg) shows the highest tensile strength (220.7 KPa), D‐phenylalanine‐based hydrogel (D‐PCPhe) exhibits the highest elongation at break (1346%), and L‐aspartic acid‐based hydrogel (L‐PCAsp) has the highest elastic modulus (206.9 KPa) and toughness (1.74 MJ m−3). D/L‐PCAsp hydrogels demonstrate stronger antibacterial capacity against Escherichia coli and Staphylococcus aureus, and D/L‐PCPhe hydrogels possess higher antifungal activity against Cryptococcus neoformans. Moreover, the resultant hydrogels exhibit prominent hemocompatibility and low toxicity, as well as excellent self‐healing capabilities (86%) and conductivity (2.8 S m−1). These results indicate that D/L‐PCAA hydrogel provides a promise for applications in wound dressings. [ABSTRACT FROM AUTHOR]

We designed CaCO3 films comprised of aragonite nanorods by mimicking the microstructure and the formation process of the calcareous skeleton of a stony coral in the sea. Hierarchically structured calcareous frameworks are produced from the center of calcification (COC) under alkaline conditions in the organism. In the first step, a seed layer consisting of crystalline nanoparticles was produced as an artificial COC on a polyvinyl alcohol sheet in a solution containing Ca2+ ions, polyacrylic acid, and a biogenic polyamine, such as putrescine, through the gradual absorption of atmospheric CO2. In the second step, aragonite nanorods grew on the artificial COC in the mother liquid obtained by mixing a putrescine solution saturated with CO2 and a CaCl2 solution containing Mg2+ and alginate. Finally, we obtained a dense, homogeneous film consisting of aragonite nanorods similar to the coral skeleton through the fixation of CO2. [ABSTRACT FROM AUTHOR]

A new coinage metal nanocluster surface molecularly imprinted polymethacrylic acid nanoprobe (NC@MIP) for the selective determination of 2,4,6-trichlorophenol (TCP) was prepared via microwave synthesis using 2,4,6-trichlorophenol as a template molecule, copper nanoclusters (CuNC) as a nanosubstrate, and methacrylic acid as a polymer monomer. It was found that the copper nanocluster MIP (CuNC@MIP) shows the strongest catalytic performance for the reduction of HAuCl4 by hydrazine hydrate for the on-site generation of gold nanoparticles (AuNPs) with the surface plasmon resonance (SPR) effects of resonance surface-enhanced Raman scattering (SERS) and resonance Rayleigh scattering (RRS) as well as absorption (Abs). When TCP was added, the CuNC@MIP nanoprobe and TCP-formed CuNC@MIP–TCP nanoenzyme with stronger catalytic activity generated more AuNPs, and the trimodal analytical signal was enhanced linearly. Therefore, a new SERS/RRS/Abs trimodal sensing platform for TCP was constructed, which was simple, rapid, sensitive, and selective. For each mode, the linear ranges were 0.0075–0.075, 0.010–0.10, and 0.010–0.10 nmol L−1, and the detection limits were 0.0010, 0.021, and 0.043 nmol L−1, respectively. The relative deviation of TCP in different water quality was 0.47%–2.5% and the recovery rate was 94.6%–108.6%. [ABSTRACT FROM AUTHOR]

Background: For a specific purpose involving the pH of menstrual blood and the pH of the vagina during menstruation, the current work describes the development of pH-responsive superadsorbent polymer (SAP)-coated menstrual pads. Acrylic acid (AA) and methyl methacrylate (MMA) were used to create a pH-responsive polymer, which was then applied layer by layer to sanitary napkins. Using FTIR, the chemical composition and structure were examined. By examining tests for absorbent capacity, swelling capacity, water retention, sorption under load, strike through, wicking height, and re-wetness under load, the performance studies of coated pads were contrasted with those of menstrual pads that are sold commercially. Additionally, the coated pad's pH response was examined to determine how stable the polymer was against pH variation. Results: The use of SAP in this study resulted in a higher free swelling capacity (102.22 g/g) for tap water and absorption under load in sanitary napkins. The absorption capacity of SAP ranges from 8 to 24 h, with values ranging from 14.84 to 132.41 g/g. Similarly, wet back and striking through analysis indicated superior outcomes in comparison with commercial products. The pH of the prepared SAP helps to maintain the necessary acidity level (pH 3.02) for the vagina during menstruation. Conclusions: Based on comparison results from FTIR, absorbency capacity, rewet, strike-through, and pH, the report recommends using the pH-responsive SAP to coat the top layer of feminine napkins. [ABSTRACT FROM AUTHOR]