Search Results (1,574)

Underwater adhesion is often compromised by interfacial hydration and insufficient bulk properties. Herein, a montmorillonite-reinforced poly (acrylic acid-co-butyl acrylate-co-2-phenoxyethyl acrylate) [P(AA-co-BA-co-PEA)/MMT] liquid adhesive was fabricated by one-pot free-radical polymerization. Solvent exchange and the balanced hydrophilic–hydrophobic composition facilitated hydration-layer displacement and intimate substrate contact, whereas MMT introduced additional physical interactions that restricted chain mobility and reinforced the adhesive bulk. The adhesive achieved underwater lap-shear strengths of 66.01–238.00 kPa on polypropylene, poly (vinyl chloride), polytetrafluoroethylene, wood, 304 stainless steel, and glass, representing improvements of 10.35–157.62% over the MMT-free adhesive. The highest strength, 238.00 ± 5.52 kPa, was obtained on 304 stainless steel. Moreover, the 180° peel strength increased by 23.90% to 107.76 ± 5.12 N m⁻¹, while the swelling ratio decreased by 33.59% to 10.20 ± 1.09%. Rheological and thermal analyses further supported the MMT-induced enhancement of the adhesive bulk. This synergistic regulation of interfacial adhesion and composite reinforcement provides a simple route toward versatile liquid adhesives for robust underwater bonding. Full article

A novel furan-functionalized polyisoprene (Furan-PIP) was synthesized via a one-pot, redox-initiated cascade approach using tert-butyl hydroperoxide (TBHP) and tetraethylenepentamine (TEPA) as the initiating system. The polymerization of isoprene proceeded through radical emulsion polymerization, accompanied by in situ epoxidation of the resulting double bonds, followed by ring-opening and furanization reactions. The chemical structure of Furan-PIP was qualitatively characterized by FT-IR and ¹H NMR spectroscopy. The appearance of characteristic signals at δ 3.97 and 3.37 ppm (furan ring protons) and δ 8.43 ppm (formyloxy proton) in the ¹H NMR spectrum, together with the corresponding FT-IR absorptions at 1725 cm⁻¹ (C=O) and 1015 cm⁻¹ (furan ring), confirmed the successful incorporation of furan and ring-opened moieties. Residual epoxide signals were negligible, indicating near-complete consumption of epoxy groups during the cascade process. Gel permeation chromatography (GPC) revealed a high-molecular-weight polymer ($\overline{{\mathrm{M}}_{\mathrm{n}}}$ = 45,892 g/mol, PDI = 2.362). The Furan-PIP exhibited a glass transition temperature (Tg) of −49.6 °C and a single-stage thermal degradation at 312 °C. Subsequently, a pre-synthesized antibacterial zinc complex Zn(L-Cl) was physically encapsulated into the Furan-PIP matrix to fabricate a composite material. The composite exhibited time-dependent antibacterial activity against Staphylococcus aureus (S. aureus) over 48 h, leveraging the intrinsic antibacterial property of Zn(L-Cl) previously reported by our group. This work presents a simple and efficient strategy for preparing furan-functionalized elastomers with potential applications in antibacterial materials. Full article

Unsaturated polyester resins (UPRs) represent challenging systems for reversible-deactivation radical polymerization (RDRP) because chain propagation, branching, and localized gelation may occur concurrently. This study systematically investigates the influence of the concentration of the RAFT agent 2-cyano-2-propyl dodecyl trithiocarbonate (CPDT), the chemical structure of the polyester prepolymer, and the nature of the acidic comonomer on the structural evolution of RAFT-modified unsaturated polyester copolymers. Three copolymer series synthesized at different CPDT concentrations were investigated: p-EGM:AA:[CPDT], p-EGM:MAA:[CPDT], and p-PGM:MAA:[CPDT]. Structural changes were characterized using H NMR, H–H COSY, UV–Vis spectroscopy, and gel permeation chromatography (GPC). Semi-quantitative analysis of normalized H NMR integral intensities was performed using Relative Vinyl Intensity (RVI), CPDT-associated methyl intensity (MI*), and normalized aliphatic intensity (AI*) to compare changes in selected proton environments among the investigated copolymer series. Increasing CPDT concentration was accompanied by a decrease in the normalized residual maleate vinyl signal, although the magnitude of this change depended strongly on copolymer composition. The most pronounced decrease in RVI was observed for the p-EGM:AA:[CPDT] series, from 0.6291 to 0.0528, whereas substantially smaller changes were observed for the p-EGM:MAA:[CPDT] series. The MI* and AI* profiles exhibited composition-dependent variations, reflecting changes in the relative contributions of CPDT-associated methyl and overlapping aliphatic proton environments, respectively. Because the aliphatic region used for AI* contains overlapping polymer- and CPDT-derived contributions, AI* is not interpreted as a quantitative measure of polymer-backbone branching. Overall, the combined NMR and GPC/SEC results reveal composition-dependent structural changes accompanying RAFT copolymerization and demonstrate that both the polyester matrix and the acidic comonomer influence the response of these heterogeneous unsaturated polyester systems to variations in CPDT concentration. Full article

Modern separation and purification technologies increasingly require materials that combine high selectivity, chemical robustness, and long-term operational stability without compromising mechanical performance. Radiation- and radical-induced graft copolymerization addresses this need by generating radical sites on polymer backbones and introducing tailored functional groups through subsequent monomer grafting. Retention of bulk properties, however, depends on controlling radiation dose, polymer structure, oxygen, and irradiation conditions so that grafting is favored over chain scission, crosslinking, and embrittlement. This review critically examines recent grafting strategies for gas and liquid separation, water treatment, radionuclide management, and resource recovery. It relates radical generation, graft growth, structural control, and functional-group chemistry to material performance and process optimization. Attention is given to radiation-induced grafting and its integration with controlled radical polymerization, especially reversible addition–fragmentation chain-transfer polymerization, to regulate graft density, chain length, and architecture. Composite and interfacial approaches are also evaluated. The review discusses the requirements and remaining barriers to practical translation, including dose optimization, long-term stability, regeneration, reproducibility, scalability, and the need for techno-economic and life-cycle assessments. Full article

Prostate cancer remains a major clinical challenge, partly due to tumour–immune interactions that contribute to immune evasion and therapeutic resistance. The CD47–SIRPα axis is a key macrophage-associated immune recognition pathway; and materials-oriented platforms that allow preliminary investigation of tumour–macrophage interaction patterns remain valuable. Here, we report an optically traceable biohybrid nanoplatform based on CD47 aptamer-functionalized fluorescent carboxyl-functional MMES-POSS hybrid nanoparticles. The nanoparticles were synthesized within 5 min using UV-induced free-radical emulsion polymerization in an ethanol–water system and exhibited spherical morphology, SEM-derived dry-state mean diameters below 100 nm, negative surface charge, and retained fluorescence due to RITC encapsulation within the crosslinked hybrid matrix; however, DLS measurements revealed pronounced aggregation and polydispersity in aqueous dispersion. SEM and EDX provided complementary evidence of nanoparticle morphology and elemental composition, whereas zeta potential and Nanodrop measurements provided evidence consistent with surface functionalization, and FTIR confirmed retention of the core POSS, carbonyl, and RITC-associated chemistry. In a PC-3/THP-1 macrophage co-culture model, Annexin V–FITC/PI flow cytometry showed a concentration-dependent redistribution of cell populations, with the most pronounced early apoptotic enrichment observed at 2 µg/mL. However, pairwise exploratory comparisons among concentrations did not reach statistical significance, and this is discussed as a limitation of the present exploratory dose–response characterization. These findings indicate preliminary interaction-associated response patterns rather than definitive receptor-specific targeting or therapeutic CD47–SIRPα blockade. Overall, this modular POSS-based biohybrid interface provides a materials-oriented platform for probing prostate cancer–macrophage interaction profiles and guiding future mechanistic validation studies. Full article

The photocatalytic degradation of Acid Orange 7 (AO7) in aqueous solution in the presence of exfoliated C₃N₄ (n-C₃N₄) as a photocatalyst was investigated under simulated solar light irradiation. The n-C₃N₄ photocatalyst was synthesized by polymerization of urea as a precursor and characterized by UV/Vis and FTIR spectroscopy, and transmission electron microscopy. Degradation products were identified by high-performance liquid chromatography with high-resolution mass spectrometry (LC–HRMS). It was found that AO7 undergoes a series of oxidation steps mediated by radicals generated during light absorption by n-C₃N₄, as well as through a photosensitization process initiated by light absorption by AO7. This results in decolorization and the formation of aromatic and aliphatic intermediates, which undergo further oxidation to simpler compounds. Full article

Extracellular polymeric substances (EPS) are recoverable high-value biopolymers from excess sludge (ES), but their antioxidant performance and enhancement strategies remain poorly understood. This study systematically investigated sludge-derived EPS (EPS_S) and Pseudomonas sp.-derived EPS (EPS_P) to elucidate the effects of source, extraction conditions, and sulfation on antioxidant activity. Compositional analysis, physicochemical characterization, Fourier-transform infrared spectroscopy, and excitation-emission matrix fluorescence spectroscopy were used for mechanistic analysis. EPS_S exhibited stronger 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity than EPS_P, associated with its higher polysaccharide content, lower protein-to-polysaccharide ratio, and more stable polysaccharide–protein heterogeneous network. Extraction conditions significantly influenced EPS yield, particle size, apparent viscosity, and composition; optimal recovery efficiency and antioxidant activity were achieved by centrifugation at 10,000 rpm for 10 min followed by dialysis through a 3500 Da molecular weight cutoff membrane. Sulfation successfully introduced sulfate ester groups while preserving the main structural framework, further enhancing the radical scavenging activities of both EPS types. Notably, EPS_S demonstrated greater structural stability during sulfation and retained higher Pb(II) removal capacity compared with EPS_P at the tested concentration. Overall, this study provides a mechanistic understanding of factors governing EPS antioxidant performance and validates sulfation as an effective enhancement strategy, supporting the high-value utilization of ES from wastewater treatment plants. Full article

This study fabricated choline–acrylic acid deep eutectic solvent (DES) hydrogels via in situ free-radical polymerization and systematically investigated the individual and co-optimization effects of lignin dosage and water content on the chemical structure, micromorphology, compressive mechanical properties, swelling behavior, and thermal stability of the hydrogels. This work quantitatively uncovers the co-optimization mechanism between the two variables in modulating crosslink density and pore architecture, thereby filling a research gap in the dual-factor co-optimization of biomass-based DES hydrogels. The results reveal that a moderate lignin dosage (0.02 g) generates abundant dynamic hydrogen bonds, densifying the crosslinked network and raising the maximum compressive stress from 0.378 MPa to 0.426 MPa, whereas excessive lignin triggers molecular aggregation and deteriorates mechanical performance. Higher water content dilutes crosslinking sites, reduces network compactness, boosts the swelling ratio while lowering compressive strength, and exerts negligible impacts on thermal degradation characteristics. FTIR analysis confirms that lignin participates in network formation solely through non-covalent hydrogen bonds, without forming new covalent bonds. A comprehensive performance evaluation identifies the optimal formulation as 0.02 g lignin and 60 g water. Although this two-factor optimization strategy provides clear experimental and theoretical guidance for designing sustainable soft materials, the present work still has limitations, including the use of only static laboratory characterizations, with no cyclic mechanical measurements or aging assessments. This study advances the customized performance tuning of lignin-derived DES hydrogels and facilitates the high-value valorization of lignin, which is promising for multifunctional green-material applications, including adsorption, flexible electronics, and biological carriers. Full article

Herein, a novel chitosan-polydopamine hydrogel was constructed through the in situ self-polymerization of dopamine in a chitosan/alkali aqueous solution. Solid-state ¹³C NMR, FTIR, and SEM confirmed that the formed polydopamine (PDA) particles easily wrapped on chitosan chains to fabricate homogeneous porous hydrogels with pearl-like PDA-chitosan nanofibrils. Thus, the hybrid hydrogels exhibited homogeneous architecture with a high compressive strength of 0.43 MPa. At elevated dopamine (DA) content, the size of PDA particles gradually enlarged from 14 to 32 nm, and a denser network structure was formed because chitosan and DA were partially crosslinked by epichlorohydrin (ECH). Furthermore, PDA endowed the hybrid hydrogels with excellent drug-loading capacity, radical scavenging, and antibacterial activities, which displayed great potential for biomedical and therapeutic applications. Therefore, we provide a new avenue for the creation of polymeric hybrid biomaterials from an alkali aqueous solution. Full article

To address the dual challenges of severe lost circulation and wellbore instability in fractured formations, an acrylamide-based lost-circulation-control gel (DF-PG) was synthesized via aqueous-solution free radical polymerization using acrylamide (AM) and sodium acrylate (SA) as monomers, N,N′-methylenebisacrylamide (MBA) as a crosslinker, and ammonium persulfate (APS) as an initiator. The optimal formulation was determined as 6.8% AM, 1.7% SA (mass ratio 4:1), 0.09% MBA, and 0.18% APS, reacted at 60 °C for 4 h. The gel achieves a 276% equilibrium swelling ratio in 20,000 mg/L simulated-formation water, with a compressive strength of 1.2 MPa and temperature resistance up to 120 °C. For fractured cores with 0.5–2.0 mm fracture widths, its sealing efficiency exceeds 95% with breakthrough pressure above 1.2 MPa, and the sealing-efficiency-retention rate remains over 85% after 72 h of scouring. DF-PG realizes the integrated functions of lost circulation control and wellbore stabilization through an “infiltration-swelling-filling“ mechanism, providing a novel technical solution for drilling operations in fractured formations. Full article

This study reports poly(acrylic acid) (PAA)-containing ceria slurries for shallow trench isolation (STI) chemical mechanical polishing (CMP). HNU15 ceria nanoparticles were prepared by precipitation at room temperature. PAA was synthesized by aqueous free-radical polymerization, characterized by gel permeation chromatography and Fourier-transform infrared spectroscopy, and used as the polymeric dispersant in both HNU15 and commercial HC10 slurries. The primary-particle sizes determined by TEM were 12.2 ± 1.5 nm for HNU15 and 14.6 ± 1.4 nm for HC10, whereas the crystallite sizes calculated from XRD were 10.2 nm and 8.7 nm, respectively. HNU15 showed a higher BET surface area and Ce³⁺ fraction than HC10, indicating measurable differences in textural properties and surface chemical states. After 5 h of milling, the HNU15 and HC10 slurries exhibited DLS d₅₀ values of 111 nm and 122 nm and zeta potentials of −53.60 mV and −49.40 mV, respectively. Both slurries maintained generally stable colloidal properties during four weeks of storage at 25 °C and 60 °C. Under the laboratory CMP conditions, HNU15 slurry exhibited an HDP-SiO₂ removal rate of 114.4 Å min⁻¹, an HDP-SiO₂-to-Si₃N₄ selectivity of 8.0, and lower post-polishing roughness than HC10. These results support the use of the PAA-containing HNU15 slurry for STI CMP applications. Full article

Whey–quercetin-loaded microspheres were synthesized using the solid/organic phase/water phase (S/O/W) method, whereas nanocapsules were prepared by interfacial polymerization. The resulting systems noted that Q1, Q2, and Q3 were characterized by polarized light microscopy (PLM), scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), high-performance liquid chromatography (HPLC), and antioxidant activity assays. Structural and spectroscopic analyses confirmed the successful encapsulation of whey and quercetin within both microsphere and nanocapsule systems. Q2 exhibited the highest encapsulation efficiency (51.79 ± 1.03%) and loading capacity (5.78 ± 0.71%), demonstrating its superior quercetin encapsulation performance. However, measurable antioxidant activity was detected exclusively in the nanocapsule formulations, whereas microspheres showed no detectable activity under the experimental conditions. Although the antioxidant activity of encapsulated quercetin was lower than that of free quercetin, the nanocapsules retained a radical-scavenging capacity, supporting their potential as effective delivery systems. Full article

This study presents the development and evaluation of a hydrogel-based superabsorbent polymer sensor (HSPS) for measuring soil suction and establishing the soil–water characteristic curve (SWCC) of unsaturated soils. Polyacrylamide (PAM) hydrogels were synthesized via UV-induced free radical polymerization using acrylamide with varying crosslinking degrees. The polymers were characterized through FT-IR and TGA analyses, confirming successful synthesis and high thermal stability. Swelling, water retention, and kinetic behavior were systematically investigated. Results indicated that lower crosslinking density significantly enhanced swelling capacity, reaching up to 3000% in distilled water, while saline environments reduced absorption due to ionic screening effects. Swelling kinetics followed anomalous (non-Fickian) diffusion behavior and were well described by the pseudo-second-order Schott model. The synthesized polymers were integrated into a modified high-sensitivity pressure sensor operating on the osmotic principle to measure matric suction. The system was validated using natural soil. Among the tested formulations, the HSPS-3 demonstrated the most reliable suction measurements, reaching values up to approximately 1 MPa without significant temperature sensitivity. The resulting SWCC exhibited bimodal characteristics consistent with the soil’s dual pore structure. The proposed method provides a cost-effective, simple, and efficient alternative for suction measurement, expanding the practical range of SWCC determination in unsaturated soil mechanics. Full article

Molybdenum-doped xerogel composites were prepared and applied in the electro-degradation of tetracycline (TTC), an antibiotic commonly prescribed for the treatment of bacterial infections. Xerogels containing 1, 6, and 14 wt% Mo were synthesized using an RF sol–gel polymerization method in cylindrical molds and were subsequently characterized in terms of their textural, chemical, and electrochemical properties, focusing on the oxygen reduction reaction (ORR). Textural characterization revealed well-developed surface areas and mesoporosity. Electrochemical analysis showed that Mo loading plays a vital role in the ORR mechanism: lower metal content favors the four-electron pathway with lower hydrogen peroxide selectivity, whereas higher Mo loadings promote bifunctional behavior, enabling both in situ H₂O₂ generation and hydroxyl radical production. Undoped and doped xerogels were very active for TTC degradation via the electro-Fenton process, but the presence of MoO₃ and Mo₂C phases improved up to 12% in removal efficiency after 480 min of treatment. Full article

To address the potential ecological risks and environmental persistence of organosilicon-fluorine viscosity reducers in conventional silicone-fluoride drilling fluid systems, this work designs and synthesizes a non-organosilicon-fluorine, high-temperature, comb-shaped zwitterionic polymer viscosity reducer, AD-XSJ. The viscosity reducer is prepared via aqueous free-radical polymerization of acrylic acid (AA), acrylamide (AM), 2-acrylamido-2-methylpropane sulfonic acid (AMPS), and dimethyl diallyl ammonium chloride (DADMAC), and it exhibits low molecular weight, uniform molecular weight distribution, and excellent thermal stability. Analyses by FT-IR, thermogravimetry, particle size, zeta potential measurements and Electrostatic potential (ESP) demonstrate that AD-XSJ dismantles the bentonite network structure through the synergistic combination of hydrogen-bonding adsorption and electrostatic repulsion, releasing trapped free water and thereby substantially reducing viscosity and gel strength. Compared with conventional organosilicon-fluorine viscosity reducers, AD-XSJ exhibits superior viscosity reduction capability under high-solid, high-temperature, and high-salinity calcium-contamination conditions, achieving viscosity reduction rates of 33.3% and 50.0% in fluids contaminated with 10.0% NaCl and 1.0% CaCl₂, respectively. In field applications under conditions of high bentonite content and calcium contamination, the viscosity reduction rates reach 57.7% and 62.5%, accompanied by markedly improved rheological properties and an average borehole enlargement rate of only 5.7%, indicating effective shale inhibition and anti-sloughing performance. Integrating efficient viscosity reduction, dispersion stabilization, and inhibition capabilities, this viscosity reducer can replace traditional organosilicon-fluorine products, reduce potential hazards to aquatic ecosystems at the source, and holds considerable promise for engineering and environmentally conscious deployment. Full article