Search Results (157)

The viscosity stability of polymer solution is one of the challenges in enhancing oil recovery, and zwitterionic copolymers present excellent viscosity stability and emulsification performance, enabling effective control of the oil/water interface mobility and enhancing oil recovery. Herein, a zwitterionic copolymer (P(AM/AMBS/MAPTAC)) containing sulfonic acid groups and quaternary amine groups was synthesized by segmentation initiation with AM, AMBS and MAPTAC as monomers. The chemical structure of P(AM/AMBS/MAPTAC) was confirmed by FTIR and ¹H NMR. The M_w value of P(AM/AMBS/MAPTAC) was 9.91 × 10⁶ g/mol, and the apparent viscosity of the 2000 mg/L solution was 24.92 mPa·s at 60 °C at a salinity of 5000 mg/L. P(AM/AMBS/MAPTAC) with sulfonic acid groups and quaternary amine groups exhibited outstanding salt tolerance and shear resistance. When the salinity was 10,000 mg/L and the shear rate was 300 s⁻¹, the apparent viscosity for the P(AM/AMBS/MAPTAC) solution was 23.45 mPa·s and the viscosity reduction rate was 69.23% at 60 °C for 30 d. Moreover, P(AM/AMBS/MAPTAC) exhibited an improved emulsifying property and a greater oil–water interface thickness than HPAM and SPAM due to the synergistic effect of the sulfonic acid and quaternary amine groups in the P(AM/AMBS/MAPTAC) molecule. The polymer flooding and alkali–surfactant–polymer flooding formed by P(AM/AMBS/MAPTAC) had high chemical oil recovery, and the oil displacement efficiency of P(AM/AMBS/MAPTAC) was higher than that of HPAM and SPAM in the polymer flooding and alkali–surfactant–polymer flooding systems. Full article

The comparison of the ability of poly(phenylene sulfone) (PPSU), a recently introduced alternative membrane polymer, with established poly(ether sulfone) (PESU), both in combination with tailored amphiphilic block copolymer additives to improve ultrafiltration (UF) membrane separation and anti-fouling performance is the focus of this work. Different poly(alkylene oxide)-containing tri- and multiblock polymers with hydrophobic blocks analogous to the respective base polymer, PPSU or PESU, of varied length were used as additives in the casting solution. Membranes were subsequently prepared via film casting and a liquid non-solvent-induced phase separation (NIPS) process. The rheological properties and thermodynamic stability of the casting solutions were investigated. At the same mass concentration, PPSU-based casting solutions show overall higher viscosity that is also more sensitive to the presence of additives compared with PESU-based solutions. PPSU-based casting solutions also have lower tolerance to non-solvents. By adding certain block copolymers in ratios of up 10 wt.% relative to the base polymer, it is possible to increase the UF performance of the membranes of PPSU and PESU. An increase in the block length of the hydrophobic block of PESU leads to a reduction in pure water permeance (PWP), whereas for PPSU, PWP is increased by the addition of additives. Especially additives with shorter PESU or PPSU block length, i.e., with a larger fraction of poly(ethylene oxide) blocks in the casting solution, seem to act as additional pore-forming agents. The water contact angle can be decreased for both additive systems, indicating a more hydrophilic membrane surface. Finally, using flower soil extract as a model substance for surface water, interesting candidates of additives that enable fouling reduction with competitive UF performance were identified for PESU and PPSU membranes. Full article

This study aimed to clarify how molecular structure regulates the dissolution and transient gel-layer behavior of polyacrylamide-based dry-powder drag reducers for slickwater fracturing. In the Materials Studio 2020 software, molecular dynamics simulations were performed on five representative homopolymers, including: polyacrylamide (PAM), polyacrylic acid (PAA), poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS), poly(N-vinylpyrrolidone) (PNVP), and poly [2-(acryloyloxy)ethyl]trimethylammonium chloride (PDAC). The results show that in pure water, PAA exhibits the strongest thermodynamic driving force with an interaction energy of −1005.5 kcal/mol and the lowest solvation free energy of −373.289 kcal/mol. Quantitative correlation analysis established that solvation energy and hydrogen bond density are primary predictors of macroscopic performance, yielding a correlation coefficient of R² > 0.94. Experiments confirm that optimized AM/AA (7:3) and AM/AMPS (5:5) anionic copolymers achieve stable viscosity within 120 ± 5 s and 160 ± 8 s, respectively, representing a 60% reduction in dissolution time compared to conventional industrial PAM homopolymers. The polarity, charge density, and chain flexibility of functional groups jointly regulate polymer dissolution behavior. Anionic groups significantly improve dissolution performance by enhancing intramolecular electrostatic repulsion and hydration. Full article

The catalytic dehydration of fructose to 5-ethoxymethylfurfural (EMF) in ethanol provides a promising approach for low-carbon chemical production. However, current catalytic systems generally suffer from a trade-off between reaction efficiency and product selectivity. Herein, we show that incorporating solvent moieties to sulfonated polymer enables the highly efficient conversion of fructose to furan compounds in ethanol via restraining product degradation. The co-polymerization of N-vinyl-2-pyrrolidinone, with divinylbenzene (DVB) and sodium p-styrene sulfonate (SPSS) gave 1.5VP/0.64SPSS/0.37DVB that has slightly lower acid contents and inferior pore structure than the co-polymer of DVB and SPSS. The 1.5VP/0.64SPSS/0.37DVB catalyst exhibited maximal EMF yield of 81.9% with a total furan yield of 92.7%, Which is remarkably higher than previous reports. Moreover, the 1.5VP/0.64SPSS/0.37DVB catalyst gave a high HMF yield in pure tetrahydrofuran. The superior performance was attributed to the improved stability of the product. Our findings will instruct the design of active and selective catalysts to facilitate the production of biomass-derived products. Full article

This study synthesizes two highly water-soluble copolymers, p(SA-co-SMAS) and p(SA-co-SMAS-co-AMPS) using sodium alginate (SA), sodium 2-methylprop-2-ene-1-sulfonate (SMAS), and 2-acrylamido-2-methylpropane sulfonic acid (AMPS, with or without addition) as precursors. Under ball milling, these copolymers are blended with aluminum sulfate and glass fibers to produce two series of cement admixtures. Compared to systems without admixtures or with pure aluminum sulfate as sole admixture, the admixture obtained from p(SA-co-SMAS) and aluminum sulfate significantly shortens the initial setting time (4.47 vs. 33.59 and 29.51 min) and final setting time (8.46 vs. 45.26 and 35.12 min), while markedly improving compressive strength (9.2 vs. 3.5 and 4.3 MPa) and flexural strength (3.5 vs. 1.0 and 1.1 MPa). This enhancement is attributed to the formation of a unique boehmite (AlO(OH)) phase in synthesized admixture, which rapidly reacts with tricalcium silicate, gypsum, and water in cement to form ettringite (Ca₆Al₂(SO₄)₃(OH)₁₂·26H₂O). The ettringite interlocks with the two-dimensional C–S–H gel, creating a stable three-dimensional network. Further blending this admixture with 200-mesh glass fibers yields a new admixture containing Al₄SO₄(OH)₁₀·36H₂O. Compared to boehmite, this phase further reduces setting times and increases average compressive strength (10.2 vs. 9.2 MPa). The admixture derived from p(SA-co-SMAS-co-AMPS) and aluminum sulfate shows even better performance: setting times are further shortened and flexural strength is significantly enhanced, owing to the presence of the more effective Al₄SO₄(OH)₁₀·36H₂O phase. Incorporating 200-mesh glass fibers into this system results in the shortest setting times (initial: 2.24 min, final: 5.73 min) and an excellent 24 h compressive strength (9.4 MPa), likely due to a unique and unexpected pore-filling effect. In contrast to conventional uses of sodium alginate as a retarder, glass fibers as mere reinforcements, and aluminum sulfate as a strength-impairing accelerator, this work demonstrates a synergistic strategy, which enables an ultra-rapid and high-strength cement setting process, offering highly significant scientific and practical value. Full article

Conventional lithium-ion batteries face issues like electrolyte leakage and interface instability. Solid-state lithium batteries with solid electrolytes address these, while solid-state polymer electrolytes (SPEs) offer safety and flexibility. This study primarily aimed to develop and synthesize a graft copolymer, PVA-g-SBMA, which was successfully synthesized by grafting [2-(methacryloyloxy)ethyl] dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA) onto poly(vinyl alcohol) (PVA). PVA provided excellent film-forming ability and mechanical strength, enhancing flexibility and stability in solid-state devices. Meanwhile, SBMA’s zwitterionic structure promoted efficient ion transport, improving ionic conductivity and solid electrolyte performance in energy storage applications. From the results, the proton assignment of the PVA-g-PSBMA zwitterionic graft copolymers was investigated via ¹H NMR spectra. The molecular weight of the graft copolymer was determined through aqueous GPC; the number average molecular weight (Mn) was 15,755, and the PDI was 1.17. The grafting efficiency of SBMA was calculated as 25%. However, the material lacked sufficient mechanical properties, leading to brittle membranes. To address this issue, we crosslinked the film to improve its mechanical properties. The grafted copolymer was crosslinked with the PEDOT:PSS as a crosslinkable sulfonated component using (3-glycidyloxypropyl)trimethoxysilane (GOPS) as the crosslinker and dimethyl sulfoxide (DMSO) as solvent to complete the crosslinking reaction. The crosslinking mechanism involved the reaction between hydroxyl groups on PVA and PSS, while the GOPS bonded with PSS, forming a robust crosslinked network. The crosslinking process was completed by heating the mixture to 120 °C. We also compared different crosslinking ratios to discuss the film performance. Lithium salts were incorporated to investigate the effect of varying lithium salt concentrations. According to EIS measurements, the best-performing system was crosslinked PVA-g-SBMA with PEDOT:PSS 0.1 wt% and LiTFSI 0.015 wt%, which reached conductivities of 4.9 × 10⁻⁴ S/cm at room temperature. We also explored the film’s thermal properties, morphologies, and chain interactions in this research. Full article

Controlling CO₂ channeling in heterogeneous reservoirs remains a major challenge for both enhanced oil recovery (EOR) and secure geological storage. AMPS-HPAM copolymers exhibit high-temperature resistance and brine tolerance compared with conventional HPAM gels, making them well suited for the harsh environments associated with CO₂ injection. Chromium-based crosslinkers (CrAc and CrCl₃) were investigated because sulfonic acid groups in AMPS can coordinate with trivalent chromium ions, enabling dual ionic crosslinking and the formation of a robust gel network. While organic crosslinked AMPS-HPAM gels have been widely studied, the behavior of chromium-crosslinked AMPS-containing systems, particularly their gelation kinetics under CO₂ exposure, remains less explored. This experimental study evaluates the gelation behavior and stability of chromium-crosslinked AMPS-HPAM gels by examining the effects of the polymer concentration, molecular weight, polymer–crosslinker ratio, temperature, pH, salinity, and dissolved CO₂. The results clarify the crosslinking behavior across a range of formulations and environmental conditions and establish criteria for designing robust gel systems. Gelation times can be controlled from 5 to 10 h, and the resulting gels maintained structural integrity under CO₂ exposure with less than 3.6% dehydration. Long-term thermal testing has shown that the gel remains stable after 10 months at 100 °C, with evaluation still ongoing. These results demonstrate that chromium-crosslinked AMPS-HPAM gels provide both durability and tunability for diverse subsurface conditions. Full article

Copolymers of polyphenylene sulfone and polyarylene ether nitrile were synthesized using nucleophilic polycondensation. 2,6-difluorobenzonitrile (DFBN), 4,4′-dihydroxybiphenyl, and 4,4′-dichlorodiphenyl sulfone were used as monomers. The structure of the obtained copolymers was confirmed by means of IR spectroscopy, and their solubility in various solvents was studied. Thermal properties were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis, as well as a set of basic mechanical properties. It was found that both thermal stability and glass transition temperature are virtually independent of the copolymer composition, while samples with a DFBN monomer content of more than 75% exhibit a melting peak in the region of 357 °C on the DSC curves, indicating an increase in the degree of crystallinity, accompanied by a deterioration in the solubility of these polymers. With increasing DFBN content, a uniform increase in elastic modulus is observed, and both bending and tensile strength increase significantly. However, the introduction of DFBN segments into the polyphenylene sulfone structure leads to a decrease in impact strength. Full article

This study presents a new ternary copolymer synthesized via aqueous free-radical polymerization from sodium humate, sodium 2-methylprop-2-ene-1-sulfonate (SMAS), and 2-acrylamido-2-methylpropane sulfonic acid (AMPS). The resulting highly water-soluble, three-dimensional porous copolymer is complexed with aluminum sulfate to form a composite admixture containing AlO(OH), which acts as a highly effective accelerator for cement hydration. This system significantly shortens the initial and final setting times to averages of 2.62 min and 4.53 min, respectively, and enhances early-age mechanical strength (1.7 MPa compressive, 1.4 MPa flexural at 6 h). These improvements are correlated with the formation of key crystalline phases, including Al₂Si₂O₅(OH)₄ and Ca₃Al₂O₆·xH₂O gel. Incorporation of 50-mesh carbon fibers further reduces setting times (2.21 min initial, 3.93 min final) and increases 24 h strength (5.2 MPa compressive, 2.7 MPa flexural), despite a slight reduction in early strength (at 6 h). In contrast, 200-mesh carbon fibers extend the initial setting time and diminish early strength, associated with the formation of less effective gel phases such as Ca₃Al₂O₆·xH₂O, (CaO)_x(Al₂O₃)₁₁, and Ca₄Al₂O₇·xH₂O. Among these, the Al₂Si₂O₅(OH)₄ phase demonstrates superior performance, while finer carbon fibers show limited effectiveness in bridging hydration products. Conventionally employed as retarders or reinforcing agents, humate-based polymers and carbon fibers are shown here to function as dual-functional admixtures—serving as efficient setting accelerators while enhancing mechanical properties through tailored material design. This strategy offers a promising pathway for developing advanced multifunctional cement admixtures. Full article

The surface morphology of high molecular weight poly(styrene-b-isoprene) block copolymer was analyzed after chemical modification. Poly(styrene-b-isoprene) was converted into poly(styrene-b-(ethylene-alt-propylene)) by hydrogenation and into poly(styrene-b-sulfonated isoprene) by mild sulfonation of the PI block. Obtained morphologies were examined by atomic force microscopy, analyzing the effect of sample preparation parameters such as solvent (tetrahydrofuran, toluene, and cyclohexane), casting technique (spin casting and drop casting), and annealing temperature [room temperature, 80, 100, and 120 °C]. Significant morphological and topographical changes were found depending on the different parameters. Each modification step introduces new variables that can affect the final structure and properties of the copolymer. Finding the balance between solvent choice, casting technique, and annealing conditions was a difficult task and required extensive experimentation and understanding of the principles of block copolymer self-assembly. Full article

Calcium oxalate (CaOx) crystals play a central role in urolithiasis, a pathological crystallization process that remains difficult to prevent. In this study, electrospun polymeric fiber (EPF) meshes of poly(acrylic acid-co-styrene sulfonate) P(AA-co-SS) were fabricated by electrospinning (ES) under controlled positive (+) or negative (−) voltages. The influence of PAA and PSS homopolymers, as well as P(AA-co-SS) copolymers with varying compositions, was evaluated as anionic scaffolds in in vitro CaOx electrocrystallization (EC) experiments. The structural and morphological features of the EPF meshes were characterized by scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Our results demonstrate that specific EPF meshes can effectively guide CaOx crystal growth, promoting the selective stabilization of either calcium oxalate monohydrate (COM) or calcium oxalate dihydrate (COD) phases. These findings highlight the potential of tailored EPF meshes as anionic scaffolds for modulating pathological CaOx crystallization. Full article

To address scaling issues in oilfield water injection, a degradable terpolymer scale inhibitor MA-AA-AMPS (terpolymer)was synthesized via aqueous solution polymerization using maleic anhydride, acrylic acid, and 2-acrylamido-2-methylpropanesulfonic acid as monomers. Characterization confirmed the presence of carboxyl, sulfonic, and amide groups in the copolymer with good thermal stability. Scale inhibition tests showed that at 2% dosage, its scale inhibition efficiency exceeded 80%, remaining above 80% in the pH range of 3–8 and over 50% at 150 °C, with excellent tolerance to high-calcium environments. Biodegradation tests revealed BOD₅/COD > 0.3, with a biodegradation rate exceeding 50% in 15 days and reaching 83.4% in 30 days, indicating environmental friendliness. This scale inhibitor effectively solves scaling problems in oilfield water injection systems. Full article

The presence of ciprofloxacin antibiotic in water is a threat to humans and aquatic life since antibiotics are currently regarded as emerging contaminants of major concern. This work reported the use of Nexar^TM film, a sulfonated pentablock copolymer, to effectively remove ciprofloxacin antibiotic from water in a sustainable approach. The removal efficiency of Nexar film was evaluated in aqueous or salty (NaCl 0.5 M) ciprofloxacin solutions as a function of contact time and the initial ciprofloxacin concentration. In the investigated conditions, the polymeric film totally removed ciprofloxacin in MilliQ solution while its removal efficiency in salty solution was approximately 73%. This lower value is due to the presence of Na⁺ ions that compete with antibiotic molecules for adsorption on active surface sites of the polymeric film. No further release of adsorbed antibiotic molecules occurred. The kinetic studies, conducted for ciprofloxacin adsorption on Nexar film in both MilliQ and salty solutions, revealed that the overall sorption process is controlled by the rate of surface reaction between ciprofloxacin molecules and active sites on Nexar surface. Furthermore, at equilibrium conditions, the isotherm model that best fits experimental parameters was not linear. This indicates that the competition between the solute and the solvent for binding sites on the adsorbent should be considered to describe adsorption processes in both MilliQ and salty solutions. Full article

To examine how reaction media influence the copolymerization processes of acrylamide-based copolymers, [BMIM]Oac and water were utilized as the reaction media. Four copolymers P(AM-SSS) (H₂O), P(AM-UA) (H₂O), P(AM-SSS) (ILs), and P(AM-UA) (ILs) were synthesized using the soluble monomer sodium p-styrene sulfonate (SSS), the insoluble monomer 10-undecylenoic acid (UA), and acrylamide (AM). The properties of the copolymers were characterized using infrared spectroscopy and ¹H NMR, and the copolymerization rates of the monomers and the segment sequences of the copolymers were calculated. The results indicated that copolymerization of SSS in ionic liquids could reduce the length of the continuous units of AM in the copolymer’s molecular chain from 231.2866 to 91.1179, with a more uniform distribution within the molecular chain. The thermal stability and micro-morphology of the copolymers were tested using a synchronous thermal analyzer and scanning electron microscopy, and the resistance of the copolymer solutions to temperature, salt, and shear were evaluated. Comparisons revealed that the three-dimensional spatial structure formed by the copolymers in ionic liquids is robust and loose. When AM and SSS polymerize in [BMIM]Oac, the resulting copolymer exhibits a higher viscosity retention rate in temperature and shear resistance tests, with a thermal decomposition temperature reaching 260 °C. Conversely, when AM and UA polymerize in [BMIM]Oac, the copolymer demonstrates good salt resistance, maintaining a viscosity retention rate of 259.04% at a Na⁺ concentration of 200,000 mg/L. Therefore, the ionic liquid [BMIM]Oac can enhance the various application performances of copolymers formed by monomers with different solubilities and AM. Full article

Currently, for the treatment of corneal diseases (keratitis–corneal opacities), synthetic corneal analogs based on polymer films or hydrogels are being developed. The requirements for the material include biocompatibility, the presence of a developed system of macropores, transparency, rapid swelling, and mechanical strength. Here, with the aim of preparing such materials, a series of gels based on a copolymer of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMP) and 2-hydroxyethyl methacrylate (or vinyl acetate, or ethyl acrylate) were obtained using cryotropic gelation. It was shown that transparent cryogels can be obtained based on the sulfonate-containing comonomer 2-acrylamido-2-methyl-1-propanesulfonic acid at a crosslinking agent concentration of 2.2 mol.%, while the nature of the acrylate comonomer did not show any effect on transparency. It was found that when using AMP and ethyl acrylate, cryogels with a developed system of macropores with a diameter of 50 to 250 μm were formed, and the mechanical strength of such cryogels was sufficient for their subsequent use as corneal implants. Moreover, the PAMP hydrogel containing 2-hydroxyethyl methacrylate or ethyl acrylate units did not affect the viability of cells even after 1 month. Full article