共查询到19条相似文献，搜索用时 46 毫秒
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随着现代化工技术的不断进步,刺激响应性水凝胶越来越受到科研人员的关注.刺激响应性短肽水凝胶可在外界的刺激包括pH值、温度、光和酶等物理和化学因素下做出相应的表现,控制其化学构象或理化性质的改变,对所受到的刺激做出相应的响应.对其独特性质进一步研究,将其运用于生物传感、药物控释和组织修复等医学领域,有着较好的发展前景.本... 相似文献
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智能聚合物凝胶是一种包含大量溶剂但又不溶解的高分子或大分子聚集体,它们具有良好的溶胀性能和三维空间网络结构,又被称为"软材料",具有独特的物理化学性质。广泛应用于药物载体、生物传感、形状记忆材料等领域。本文综述近年来国内外开发的智能响应性凝胶,重点介绍响应性凝胶的结构特征和性能特点。并对响应性聚合物凝胶的发展进行展望。 相似文献
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介绍了伤口愈合的过程以及愈合过程中伤口处微环境的变化,叙述了目前根据伤口处不同环境变化(如pH、温度、活性氧含量和葡萄糖含量等)而设计的智能响应水凝胶,总结了可以应对2种及以上伤口微环境变化的双重或多重刺激响应性水凝胶的制备过程,以及水凝胶如何对伤口实现智能响应和精准治疗的应用,并讨论了今后应用于伤口愈合水凝胶的设计方向。认为目前的水凝胶多数用于浅表创伤的治疗,如何对深度损伤的慢性伤口实现加速愈合的效果是扩展水凝胶应用的关键;从材料角度出发,可以深度研究创面愈合机制,设计开发多重刺激响应水凝胶以满足不同类型的创面的需求,从而使水凝胶在伤口愈合方面有更广阔的应用前景。 相似文献
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刺激响应型聚合物在药物释放领域的应用越来越广泛,研究也越来越受到重视.根据不同类型的刺激条件,综述了pH响应型、温度响应型、葡萄糖响应型、场响应型等一系列刺激响应型药物释放体系的应用和研究进展. 相似文献
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Microscopic hydrogel spheres can be used to improve the mechanical properties of conventional hydrogels. We prepared ionic‐covalent entanglement (ICE) hydrogel microspheres of calcium cross‐linked gellan gum and genipin cross‐linked gelatin using a water‐in‐oil emulsion‐based processing technique. The method was optimized to produce microspheres with number average diameter 4 ± 1 µm. These ICE microspheres were used to reinforce gelatin hydrogels and improve their compressive mechanical properties. The strongest microsphere reinforced hydrogels possessed a compressive mechanical stress at failure of 0.50 ± 0.1 MPa and a compressive secant modulus of 0.18 ± 0.02 MPa. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40557. 相似文献
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In this article, we report a facile strategy for preparing high‐mechanical‐strength ferrohydrogels containing magnetic nanoparticles homodispersed by a thermodynamically stable Pickering emulsion (PE). After the monomers were mixed with the PE, including methacryloxy propyl trimethoxyl silane emulsified by ferric oxide (Fe2O3) nanoparticles as the dispersed phase, hydrogels were synthesized by free‐radical polymerization. In contrast to conventional hydrogels crosslinked by a molecular crosslinker, in our new approach, the magnetic PE particles served as individual, multifunctional crosslinkers. Characterizations of the swelling behavior, the mechanical properties, and other properties indicated that our ferrohydrogels exhibited outstanding physical performances that were superior to those of traditional hydrogels and magnetic responsiveness. These ferrohydrogels may have applications in soft and controllable actuators. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41950. 相似文献
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Cellulose/Polypyrrole (PPy) composite hydrogels were prepared by in situ chemically oxidative polymerization of pyrrole in the cellulose matrix. Ferric chloride (FeCl3) was used as an oxidant and four sulfonic compounds were used as dopants in order to investigate the effects on the properties of cellulose/PPy conductive composite hydrogels. The extent of polymerization of PPy was determined by the amount of the oxidant and the composite hydrogels with oxidant at 0.3M?0.5M exhibited the higher conductivities for the intrachain and interchain conductivities of conductive polymers; the fracture stress of the composite hydrogels could be up to 26.25 MPa with a strain of 86.8% when the oxidant was at 0.5M. Doping is an efficient way to improve the conductivity of the composite hydrogels and four kinds of dopant were compared in this work. Long alkane chain and side group in dopants can increase the steric hindrance of PPy polymerization which resulted in the lower conductivity of the composite hydrogels compared to dopants with smaller steric hindrance. The conductivity of the composite hydrogel firstly increased and then decreased with the concentration of dopants from 0.1M to 1.0M in this work. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43759. 相似文献
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Xiaojing Zhang Weiwei Shen Jingcheng Dou Yang Meng Shaoming Fang Ruixue Liu 《应用聚合物科学杂志》2020,137(12):48486
In this study, water-soluble octa(3-chloroammoniumpropyl) silsesquioxane (OCAPS) was found to aggregate into nanoparticles with a positive charge in solution, which can attract persulfate anion radical to initiate N-isopropylacrylamide monomers. Due to the electrostatic and hydrogen bond interaction between OCAPS and poly(N-isopropylacrylamide) (PNIPAM) chain, OCAPS can act as an effective physical crosslinker to result in a nanocomposite hydrogel (OCAPS-PNIPAM) with very small loading N, N′-methylene-bisacrylamide (50–100 ppm). The incorporation of OCAPS increases the crosslinking degree of the PNIPAM hydrogel and decreases the swelling ratio in deionized water. The mechanical properties of OCAPS-PNIPAM hydrogel were enhanced greatly by the presence of OCAPS and can be adjusted by the feed ratio. The compression and elasticity moduli vary from 3.52 to 7.59 kPa and 7.67 to 33.91 kPa, respectively. The tensile strength ranges from 6.82 to 243.41 kPa with fracture energy between 503.5 and 4781.7 J·m−2. Rheological measurements suggest that OCAPS-PNIPAM hydrogels have stable networks and the loss factor decreases as increasing OCAPS content. OCAPS-PNIPAM hydrogels also can self-heal under certain conditions with low crosslinker loading. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48486. 相似文献
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Sina Naficy Shota Kawakami Sasha Sadegholvaad Minato Wakisaka Geoffrey M. Spinks 《应用聚合物科学杂志》2013,130(4):2504-2513
Hydrogels are polymer networks swollen in water. Because of their soft and wet nature, and their ability to show large volume changes, hydrogels can be useful in many biomedical and actuator applications. In these applications, it is crucial to tune the mechanical and physical properties of a hydrogel in a controllable manner. Here, interpenetrating polymer networks (IPNs) made of a covalently crosslinked network and an ionically crosslinked network were produced to investigate the effective parameters that control the physical and mechanical properties of an IPN hydrogel. Covalently crosslinked polyacrylamide (PAAm) or poly(acrylic acid) (PAA) networks were produced in the presence of alginate (Alg) that was then ionically crosslinked to produce the IPN hydrogels. The effect of ionic crosslinking, degree of covalent crosslinking, AAm : Alg and AA : Alg ratio on the swelling ratio, tensile properties, indentation modulus, and fracture energy of IPN hydrogels was studied. A hollow cylindrical hydrogel with gradient mechanical properties along its length was developed based on the obtained results. The middle section of this hydrogel was designed as a pH triggered artificial muscle, while each end was formulated to be harder, tougher, and insensitive to pH so as to function as a tendon‐like material securing the gel muscle to its mechanical supports. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2504–2513, 2013 相似文献
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Hydrogels based on acrylamide (AM) and ethanol organosolv lignin (EOL) with high swelling and good mechanically elastic properties were synthesized in an alkaline solution. EOL was used as a reactive filler for the preparation of AM‐based hydrogels. The impact of EOL addition on the physicochemical properties of AM‐based hydrogels was investigated using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy, and their mechanical properties were examined. The water swelling ratio of the prepared hydrogels increased with the increase of EOL content, and their maximum swelling ratio could reach up to 180. Mechanical measurements indicated that their tensile strength was highly dependent on the amount of EOL, and their elongation at break reached up to 1400%. The formation mechanism of EOL composite hydrogels was probably that most of AM was synthesized into the crosslinked poly(acrylic amide) network, and small quantities of AM was hydrolyzed to acrylic acid ions under alkaline condition. The chain transfer of free radicals from AM and/or AA to EOL molecules occurred in the polymerization process. With increasing EOL content in the hydrogels, an interpenetrating polymer network might be mainly formed by the hydrogen bonding between EOL and AA and/or AM molecules. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42638. 相似文献
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Ionic‐covalent entanglement (ICE) hydrogels are a recently introduced new type of robust materials for potential future application in the fields of tissue engineering and soft robotics. Here the degradation behavior of gellan gum/polyacrylamide ICE hydrogels immersed in PBS or enzyme solutions is presented. It is demonstrated that ICE gels immersed in enzymes became stiffer, whereas under cyclic testing their mechanical responses stabilize after 10 loading/unloading cycles whether immersed in PBS or enzyme solutions. The leachates of the ICE hydrogels were found to be non‐cytotoxic for the growth of L929 and PC12 cells. These findings will be of benefit to the future development of tissue engineering applications based on these gel materials. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41216. 相似文献
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Clay aerogels have many advantages as one of the lowest density family of materials current technology can provide; they possess very low thermal conductivities, high porosities, and high surface areas. Although the mechanical properties of native clay aerogels are rather low, incorporating water‐dispersible polymers into the clay gel before they are processed into aerogel forms can easily produce more robust, low‐density composites. Various processing modifications and additives can be employed to strengthen the aerogel material, but currently, the materials have some notable weaknesses in abrasion resistance, water absorption, and flexural properties. In this study, we employed a low‐cost rubber coating material to quickly and efficiently address all three of these problems. After coating, the aerogels gained significant mechanical reinforcement, a 20‐fold increase in flexural modulus and a 15‐fold increase in yield stress, while exhibiting an increase of only 8% in the thermal conductivity. Improvements such as these can improve the commercial applicability of clay/polymer aerogels as thermal insulation materials. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
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Jaehyeon Park Sukyoung Kim Shim Sung Lee Jong-Hyun Kim Joung-Man Park Ji Ha Lee Jong Hwa Jung 《应用聚合物科学杂志》2021,138(42):51235
This study focused on controlling the stretching property of gels. This resilience is dependent on the water content in the calix[4]arene-based gel solvent system, where the stretching property of gels could be controlled upon the addition of water. The storage (G′) and loss (G″) moduli of the calix[4]arene-based gels prepared in solvent systems with different water contents were investigated via rheological measurements. By the strain sweeps, the values of G′ decreased, while tan-delta increased with water content in the solvent system. In addition, a significant changes in the G′ and G″ values were observed upon the addition of water by frequency sweeps. In particular, the decrease in the G″ value of the gel prepared from the 1,3-alternated calix[4]arene derivative ( HC4 ) and diisocyanate linker ( HDI ) in DMSO/H2O mixed solvent (8:2 v/v) was approximately 5-fold larger than that of the gel prepared in 100% DMSO. Thus, this novel approach would useful for the development of new soft materials with finely controllable mechanical properties. 相似文献