In situ synthesis of poly(acrylic acid) physical hydrogels from silica nanoparticles
In situ synthesis of poly(acrylic acid) physical hydrogels from silica nanoparticles
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DOI：
10.1039/c1sm06647a
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发表时间：
2012-01-01
期刊：
影响因子：
3.4
通讯作者：
Xie, Xu-Ming
中科院分区：
文献类型：
--
作者：
Yang, Jun;Wang, Xi-Ping;Xie, Xu-Ming
本文介绍了一种利用二氧化硅纳米粒子表面原位聚合制备物理水凝胶的方法。用γ-甲基丙烯酰氧基丙基三甲氧基硅烷处理过的SNs，通过共价键接枝得到一系列聚丙烯酸链。接枝链之间的缠结构成了水凝胶网络，SN起着“类似交联点”的作用。SNs被接枝聚合物链包裹，形成“核-壳”结构。结果表明，接枝链的分子量、SNs的含量和粒径对水凝胶的性能有影响。与化学交联的水凝胶相比，杂化水凝胶具有优异的力学性能，在100wt%的水含量下，可以承受高达3.16MPa的应力和440%的伸长率。凝胶-溶胶现象证实该杂化水凝胶属于物理交联型。
This paper introduces a versatile method to synthesize physical hydrogels by silica nanoparticle (SN) surface in situ polymerization. A series of poly(acrylic acid) chains were covalently grafted from the SNs that were treated with gamma-methacryloxypropyl trimethoxy silane. The entanglements among the grafted chains constructed the hydrogel networks and the SNs played the role of 'analogous crosslinking points'. The SNs were encapsulated by the grafted polymer chains and formed a 'core-shell' structure. It was found that the molecular weight of the grafted chains and the content and diameter of the SNs affected the hydrogel's properties. In comparison with chemically crosslinked hydrogels, the hybrid hydrogels exhibited excellent mechanical properties and could endure stress as high as 3.16 MPa and an elongation of 440% at a water content of 100 wt%. The gel-sol phenomenon confirmed that this hybrid hydrogel belonged to the physically crosslinked type.