SOFT MATERIALS
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2019
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IF 0.973
Minying Wang,Le Luo,Lihua Fu,Hua Yang
Polyacrylamide/sodium alginate (PAM/SA) hydrogel was prepared from sodium alginate (SA) and acrylamide (AM) by covalently cross-linking. Temporary shape double network PAM/SA hydrogels were obtained by ionic cross-linking formed by complexation of SA and six metal cations (Fe3+, Cu2+, Ag+, Ca2+, Ni2+, and Co2+), among the PAM/SA—Fe3+ hydrogels has the best shape fixity ratio (83%). When the hydrogel is placed in different recovery liquids (sodium citrate, EDTA, sulfuric acid, and potassium carbonate), the shape recovery ratio (98.9%) is the best in sodium citrate solution, and the recovery time (182 s) of the hydrogel is the shortest. In general, Fe3+, Cu2+, and Ag+ are suitable for the construction of ionic-shape memory hydrogels. The PAM/SA hydrogels also exhibited excellent adjustable mechanical properties by changing metal cations and soaking time. The strategy could broaden the construction of ion-responsive shape-memory hydrogels.
研究领域:
材料科学
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生物医学工程
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产品关联
DOI
高影响因子
ENERGY & FUELS
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2026
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IF 6
Shuai Zhou,Qiuyan Quan,Hongke Yang,Zhi Ye,Xueli Long,Tinglei Liu,Haien Yang,Dongzhi Yang
This study systematically investigates the swelling, time-dependent mechanical decay, and degradation of polyacrylamide (PAM)-based gels under simulated high-temperature reservoir conditions. A Ca2+-induced “environmentally self-enhancing” PAM/sodium alginate (SA) composite gel was designed to alleviate the pronounced performance decline caused by swelling and degradation. In this system, progressive cross-linking between SA and Ca2+ in formation water leads to the formation of an interpenetrating network (IPN), which contributes to improved structural stability. Experimental results indicate that incorporating 1.5% SA into a 20% PAM gel increases the swelling strength by a factor of 6.7, while the three-month strength retention improves from 14% to 50%. The composite gel also shows enhanced fatigue resistance and a delayed swelling response. In addition, PAM/SA microspheres prepared via inverse emulsion polymerization exhibit improved mechanical robustness after Ca2+ cross-linking, with the elastic modulus increasing by 36%. Core flooding experiments show that PAM/SA microspheres are able to gradually form stable plugging structures in porous media. After 7 days of swelling, the plugging ratio increases by 23% and the oil displacement efficiency improves by 3% compared with PAM microspheres. Microfluidic visualization further indicates that swollen microspheres form reconfigurable deposits within pore throats, which suppress preferential flow. Both the plugging pressure and the frequency of pressure fluctuations increase noticeably, and the displacement efficiency rises by 4%, reflecting enhanced flow field regulation. Overall, this study provides cross-scale experimental evidence for the environmentally induced strengthening mechanism of PAM/SA gels and suggests their potential application in deep conformance control.
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DOI
高影响因子
Journal of Energy Storage
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2023
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IF 9.4
Qinzheng Hu,Shuzhen Cui,Kanjun Sun,Xiuting Shi,Wenxing Miao,Xiangbing Wang,Hui Peng,Guofu Ma
In recent years, the research focus of flexible supercapacitor is to improve its energy density . The recently reported improved energy storage method is to introducing suitable redox-additive in gel electrolytes to enhance their redox-activity. Herein, a novel stretchable, redox-active and double-network 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxy-containing polyacrylamide/alginate/H 2 SO 4 (PAM/SA/H 2 SO 4 /TEMPOL) hydrogel electrolyte is prepared by radical cross-linking polymerization and solvent displacement process. The PAM/SA/H 2 SO 4 /TEMPOL hydrogel possesses superior stretchability (750 %) because of the electrostatic interactions between the -NH 3+ groups of the PAM and the -COO − groups of SA . In addition, the introduction of the TEMPOL additive into PAM/SA/H 2 SO 4 /TEMPOL hydrogel electrolyte of flexible EDLC can gain a high specific capacitance (386 F g −1 ) and high energy density of 24.5 Wh kg −1 , which is due to dual redox reactions both positive/negative electrode. This study provides a new strategy for designing a multifunctional redox hydrogel electrolyte.
研究领域:
材料科学
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电化学
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能源存储
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Fan Zhang,Shanshan Jiang,Dezhen Zhao,Yunhe Diao,Xuying Liu,Jinzhou Chen,Jie Liu,Huige Yang
Hydrogels possess several advantageous characteristics, including transparency, biocompatibility, and ionic conductivity, making them promising for applications in flexible electronics, drug delivery, ionic skin, and electrolytes. Nevertheless, creating a robust conductive and antifreezing hydrogel with enduring environmental stability remains a significant challenge. This study, based on the salt-out effect of alkali metal ion salts and binary solvent systems, employs a straightforward one-pot solvent exchange method to introduce dynamic and reversible non-covalent bonds (hydrophobic association and hydrogen bonds) into a polyacrylamide-sodium alginate (PAM-SA) dual-network hydrogel with excellent flexibility and biocompatibility. By adjusting the types of ions and cryoprotective agents (CPA), a series of ion-conductive organic hydrogels with anti-freezing properties were successfully prepared. The resulting PAM/SA-Gly-KCl 1M hydrogel exhibits commendable mechanical properties (with a tensile strain of up to 1465 %, a tensile strength of 166 kPa, and toughness of 1354 kJ m 3 ), high ionic conductivity (0.59 S/m), outstanding frost resistance (–100 °C), and sustained long-term stability (maintaining 70 % of its weight for over one month in an open environment). Therefore, sensors based on organic hydrogels exhibit exceptional characteristics, including high strength, superior transparency, and dependable operation in low-temperature conditions. Its remarkable sensing sensitivity and stability and antifreeze properties facilitate operation across an extensive temperature range and contribute to an extended operational lifespan. Overall, this sensor proves conducive to developing enduring flexible electronic products in challenging environments, thereby unveiling novel prospects for the realms of smart wearable technology and health monitoring.
研究领域:
材料科学
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化学工程
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生物医学工程
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电子学
✓ 已验证
产品关联
DOI
高影响因子
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