MOLECULES
·
2021
·Vol. 26
·期 13
·3999
·
IF 4.412
Huiyuan Luo,Fuping Dong,Qian Wang,Yihang Li,Yuzhu Xiong
The performance of hydrogels prepared with traditional natural starch as raw materials is considerable; the fixed ratio of amylose/amylopectin significantly limits the improvement of hydrogel structure and performance. In this paper, starch hydrogels were prepared by physical blending and chemical grafting, with the aid of ultrasonic heating. The effects of different amylose/amylopectin ratios on the microstructure and water retention properties of starch hydrogels were studied. The results show that an increase in amylopectin content is beneficial to improve the grafting ratio of acrylamide (AM). The interaction between the AM grafted on amylopectin and amylose molecules through hydrogen bonding increases the pores of the gel network and thins the pore walls. When the amylopectin content was 70%, the water absorption (swelling 45.25 times) and water retention performance (16 days water retention rate 44.17%) were optimal. This study provides new insights into the preparation of starch-based hydrogels with excellent physical and chemical properties.Keywords:ultrasonic chemistry;hydrogel;starch;porous structure;water-retaining
研究领域:
材料科学
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Wenqi Wang,Yizhuo Liu,Shiqiang Wang,Xuemei Fu,Tiancheng Zhao,Xin Chen,Zhengzhong Shao
Flexible ionic conductive hydrogel is attracting significant interest as it could be one of the crucial components for multifunctional ionotronic devices. However, their features of inevitably drying out without package and freezing at subzero temperatures may greatly limit the applications of conventional hydrogels in specific situations. Here, we present an ionic conductive hydrogel with water retention and freezing tolerance that consists of silk fibroin, ionic liquid, water, and inorganic salt. It is discovered that the ionic liquid serves multiple purposes to prevent water evaporation, decrease the freezing point, provide the essential conductivity of the hydrogel, etc. As a binary mixed solvent, the ionic liquid/water mixture enhances both water retention and freezing tolerance of the hydrogel electrolyte. Based on the silk fibroin (SF)/1-ethyl-3-methylimidazolium acetate (EMImAc)/H2O/KCl hydrogel electrolyte, the flexible fiberlike supercapacitor could still function well at a temperature as low as −50 °C and after being stored in the open air for a long time. It is anticipated that this hydrogel will prove useful in developing new applications operating under harsh environments.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymer Chemistry
·
2019
·Vol. 10
·期 37
·5151-5158
·
IF 4.76
Xiao Feng Cui,Wen Jiang Zheng,Wei Zou,Xing Yong Liu,Hu Yang,Jie Yan,Yang Gao
Hydrogels as fire-resistant materials have attracted great attention due to their high water content and tailored shapes that can cover various surfaces. As fire-resistant materials, hydrogels should be mechanically tough, self-healable, and able to retain water under ambient environment for a long period. However, this combination is rarely realized. Here in this work, a series of Li-alginate/poly(acrylamide-co-stearyl methacrylate) [Li-alginate/P(AAm-co-SMA)] hydrogels with fully physically cross-linked interpenetrating networks have been prepared. The obtained hydrogels exhibit the maximum fracture energy of ∼6800 J m−2, which is high enough for being used as fire-resistant materials. A fire resistance test suggests that the hydrogel is capable of withstanding 1300 °C flame for 50 s. The self-healing property ensures the recovery of the fire-resistance properties of the gels after being scratched or damaged. The water retention capacity promises the time-effectiveness of fire-resistance lasting for 6 months and even longer. In a word, the Li-alginate/P(AAm-co-SMA) hydrogels are potentially being applied as fire-resistant coatings for structures, trees and fireproof clothes.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 35
·12873-12882
·
IF 8.067
Yiyan Gao,Yang Gao,Zhixin Zhang,Yuanrui Wang,Xiuyan Ren,Fei Jia,Guanghui Gao
Conductive hydrogels are ideal materials for preparing wearable strain sensing devices due to their flexibility and stretchability. However, most hydrogels exhibit poor freezing resistance and weak water-holding ability, thus hindering the working range of hydrogel-based sensors in extreme environments. Here, a conductive hydrogel featuring conspicuous anti-freezing and water retention abilities was prepared by integrating amylose (AMY) into a polyvinyl alcohol (PVA)/glycerol/NaCl hydrogel. AMY possesses a number of hydroxyl groups, which could interact with PVA and glycerin via hydrogen bonds, enhancing the toughness of the hydrogel. Meanwhile, based on the strong hydrogen bonding between glycerol and water molecules, the hydrogel displayed water-retaining properties after 7 days of storage in an open environment. The synergistic action of NaCl and glycerol prevented the crystallization of water at low temperatures, endowing the hydrogel with outstanding conductivity and stretchability at −20 °C. Furthermore, the hydrogel-based wearable strain sensor exhibited excellent sensitivity (GF = 2.55), fast response/recovery time, and good durability and biocompatibility, which accurately detected joint movements and physiological signals at room temperature or under extreme conditions. Therefore, conductive hydrogels would possess significant application prospects in health detection, disease diagnosis, and artificial intelligence.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 6
·1448
·
IF 3.1
Chunhui Shi,Xifeng Lv,Jingfan Peng,Jikui Zhu,Fengqin Tang,Libing Hu
Although humic acids (HAs) have been used to prepare absorbent hydrogels, their applications in many areas, such as agriculture, wastewater treatment and hygienic products, are not satisfactory due to their low solubility in organic solvents. In this work, biochemical fulvic acid (BFA), as a kind of HA, was initially methylated for preparation of the methylated BFA (M-BFA), which contributed to enhancing the solubility in organic solvents. Then, M-BFA reacted with N,N′-methylenediacrylamide(MBA) in the N,N-Dimethylacrylamide (DMAA) solution, and the expected hydrogel (M-BFA/DMAA) was successfully obtained. XPS confirmed that there were more C=O and C-N groups in M-BFA/DMAA than in DMAA; thus, M-BFA/DMAA was able to offer more reactive sites for the water adsorption process than DMAA. The combined results of BET and SEM further demonstrated that M-BFA/DMAA possessed a larger BET surface area, a larger pore volume and a more porous structure, which were favorable for the transfer of water and accessibility of water to active sites, facilitating water adsorption and storage. In addition, the swelling ratio and water retention were investigated in deionized (DI) water at different conditions, including test times, temperatures and pHs. Amazingly, the swelling ratio of M-BFA/DMAA was 10% higher than that of DMAA with the water retention time from 100 to 1500 min. Although M-BFA/DMAA and DMAA had similar temperature sensitivities, the pH sensitivity of M-BFA/DMAA was 0.9 higher than that of DMAA. The results proved that M-BFA/DMAA delivered superior water retention when compared to the pristine DMAA. Therefore, the resultant materials are expected to be efficient absorbent materials that can be widely used in water-deficient regions.
研究领域:
材料科学
·
环境科学
·
农业科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Hongliang Wei,He Wang,Huijuan Chu,Jingjing Li
In this work, a kind of slow-release and water-retention fertilizer was fabricated by free radical copolymerization of potato starch, acrylic acid, acrylamide, and β-cyclodextrin modified by maleic anhydride, accompanying halloysite nanotubes whose cavities were enlarged by acidification and loaded with urea in advance. The fertilizer was characterized by FTIR, TGA , SEM, TEM, and XRD. Its swelling behavior in distilled water and salt solutions as well as the ability to hold water was studied by weighing method. Finally, its controlled-release behavior to urea was investigated. The results suggested the as-prepared fertilizer had good abilities to retain water and control urea release. Moreover, the addition of halloysite helped to improve the release properties of the fertilizer. The study on urea release kinetics indicated the release behavior of urea in water was controlled by its concentration, whereas the release behavior of urea in soil fitted with Fickian diffusion mechanism.
研究领域:
农业科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2020
·Vol. 221
·期 22
·2000237
·
IF 2.335
Xin Han,Mengyu Li,Zewen Fan,Yu Zhang,Huihui Zhang,Qiaoling Li
Traditional self-healing hydrogels have great application prospects in biological engineering because of their extremely high water content, but their durability cannot be easily guaranteed. Therefore, developing a rapid self-healing hydrogel with long-lasting water retention capacity is still a significant challenge. A high-strength and fast self-healing hydrogel with an interpenetrating double network based on polyvinyl alcohol/agar-ethylene glycol (PVA/agar-EG) is proposed. Polyvinyl alcohol (PVA) and agar are designed for the construction of the interpenetrating network. Furthermore, the introduction of a borate-bonding dynamic action mode affords the hydrogel with extraordinary mechanical strength and rapid self-healing. The addition of EG as a traveling solvent enables the sample to retain water and prevents freezing in harsh environments, including at high temperatures of 80 °C and extremely low temperatures of −40 °C. Additionally, owing to the intelligent remolding ability of the PVA/agar-EG hydrogel, the material can be recycled to prolong the service life of the hydrogel. Overall, the PVA/agar-EG hydrogel developed in this study can provide a new general strategy for the development of intelligent self-healing devices, and hydrogels can be applied in complex environmental engineering.
研究领域:
生物工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CEMENT AND CONCRETE RESEARCH
·
2021
·
IF 10.933
Peihua Zhong,Zhangli Hu,Michele Griffa,Mateusz Wyrzykowski,Jiaping Liu,Pietro Lura
This paper examines the mechanisms of desorption within cement pastes for superabsorbent polymers (SAP) with different sorption kinetics: retentive and non-retentive (self-releasing). Despite the different behavior in solution, both SAP types mitigated the autogenous shrinkage of cement pastes. 1 H NMR and X-ray tomography showed that the cavities formed by both SAP types were saturated until 9–11 h after mixing, while the entrained water in the cavities redistributed to the cement matrix afterwards. In particular, the non-retentive SAP might have rapidly released the absorbed water, but the released water stayed in the original cavities. Therefore, the behavior of the SAP in the pore solution may not completely determine their internal curing performance in cement pastes. In particular, the initial absorption that forms the solution-filled cavities might be more important than whether the SAP are able to retain the solution for extended periods of time or not.
研究领域:
材料科学
·
土木工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Yangengchen Zhong,Mingjie Liu,Chuyang Xiang,Yeying Lin,Youjun Guan,Kunyu Ren,Chengyun Ning,Lei Zhou,Limin Lu,Rumin Fu,Guoxin Tan
Conductive hydrogels are characterized by their extraordinary stretchability, flexibility, and biocompatibility, making them ideal materials for flexible wearable sensors. However, they often encounter challenges such as freezing and water loss, which can adversely affect their conductivity and stretching performance. In this study, we introduce a conductive hydrogel incorporating polyethylene glycol (PEG), acrylic acid (AA), acrylamide (AM), and lithium chloride (LiCl), which exhibits low-temperature tolerance, resistance to drying, self-adhesion, and mechanical robustness. The hydrogel’s excellent mechanical properties, including an elongation at break of 1120% and a toughness of 2.9 MJ m–3, are attributed to the formation of a tight polymer network between P(AA-AM) and PEG through hydrogen bonding. The multiple hydrogen bonding system between PEG and the polymer networks, combined with the hydration of LiCl and electrostatic interactions between the carboxyl group and Li+, significantly enhances the hydrogel’s freezing resistance (down to −60 °C), water retention (with only 20% water loss after 15 days), and self-adhesion (with an adhesion strength to pig skin of up to 55.08 kPa). When employed as a flexible sensor, the P(AA–AM)/PEG/LiCl hydrogel exhibited excellent sensing properties for monitoring various human motions, with an impressive gauge factor of 1.91 and electrical conductivity of 4.50 S m–1 Moreover, it maintained a high electrical conductivity (3.82 S m–1) even at −20 °C. The conductive hydrogel consistently produced stable and reliable electrical signals in response to external mechanical stimuli, making it a preferred material for human motion monitoring.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2023
·Vol. 24
·期 11
·9208
·
IF 5.6
Yajun Hou,Baojuan Deng,Shanshan Wang,Yun Ma,Xing Long,Fei Wang,Chengrong Qin,Chen Liang,Shuangquan Yao
The use of fertilizer is closely related to crop growth and environmental protection in agricultural production. It is of great significance to develop environmentally friendly and biodegradable bio-based slow-release fertilizers. In this work, porous hemicellulose-based hydrogels were created, which had excellent mechanical properties, water retention properties (the water retention ratio in soil was 93.8% after 5 d), antioxidant properties (76.76%), and UV resistance (92.2%). This improves the efficiency and potential of its application in soil. In addition, electrostatic interaction and coating with sodium alginate produced a stable core–shell structure. The slow release of urea was realized. The cumulative release ratio of urea after 12 h was 27.42% and 11.38%, and the release kinetic constants were 0.0973 and 0.0288, in aqueous solution and soil, respectively. The sustained release results demonstrated that urea diffusion in aqueous solution followed the Korsmeyer–Peppas model, indicating the Fick diffusion mechanism, whereas diffusion in soil adhered to the Higuchi model. The outcomes show that urea release ratio may be successfully slowed down by hemicellulose hydrogels with high water retention ability. This provides a new method for the application of lignocellulosic biomass in agricultural slow-release fertilizer.Keywords:antioxidant;hemicellulose-based hydrogels;urea sustained release;water retention performance
研究领域:
农业科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Communications
·
2024
·
IF 3.7
Chao Yang,Dalie Liu,Sheng Wang,Shiyu Zhou,Yan Lv,Yihua Ni,Zhongjin Ni
Flexible hydrogels have received significant attention for their excellent mechanical properties, fast response and good strain sensitivity. However, relatively little research has been conducted on the investigation of hydrogels that exhibit frost resistance, water retention, and transparency characteristics. In this paper, a new flexible strain sensors material was prepared by introducing calcium chloride (CaCl 2 ) and hydrolysed keratin (HK) into the polyvinyl alcohol (PVA) system through complex chemical bond. The PVA/CaCl 2 /HK hydrogel exhibited excellent mechanical properties, with a tensile strength of 1.578 MPa and a maximum strain of 934 %. Moreover, it showed high transparency, with a transmittance of up to 90 %. The hydrogel demonstrated remarkable water retention properties with about 8 hours of dry resistance under constant temperatures of 40 °C, 60 °C, 80 °C and 100 °C. Additionally, it had excellent frost resistance with a glass transition temperature of −23 °C, making it environmentally tolerant and capable of maintaining long-term stability. Notably, during the experiment, the PVA/CaCl 2 /HK hydrogel exhibited excellent electrical conductivity and self-powered performance, with a power supply capacity of approximately 14.6 mV. The results of this work provide a promising direction for the development of electronic materials for powered hydrogel strain sensors.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
Scientific Reports
·
2024
·Vol. 14
·期 1
·1-11
·
IF 3.8
Yumang Zhang,Yongheng Wang,Chengyu Wang,Yunhang Gao,Shuxia Liu,Zhonglei Xie,Hongyan Chang
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.
研究领域:
材料科学
·
环境科学
·
农业科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）