High-water-content mouldable polyvinyl alcohol-borax hydrogels reinforced by well-dispersed cellulose nanoparticles: Dynamic rheological properties and hydrogel formation mechanism
High-water-content mouldable polyvinyl alcohol-borax hydrogels reinforced by well-dispersed cellulose nanoparticles: Dynamic rheological properties and hydrogel formation mechanism
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DOI：
10.1016/j.carbpol.2013.11.045
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发表时间：
2014-02-15
影响因子：
11.2
通讯作者：
Wu, Qinglin
中科院分区：
文献类型：
--
作者：
Han, Jingquan;Lei, Tingzhou;Wu, Qinglin
在水体系中制备了纤维素纳米颗粒（CNP）增强聚乙烯醇-硼砂水凝胶。研究了CNPs的粒径、长径比、晶体结构和表面电荷对复合水凝胶流变性能的影响。流变学测试证实，分散良好的CNPs加入到PB体系中，显著提高了水凝胶的粘弹性和刚度。获得的独立、高弹性、可塑的水凝胶在连续阶跃应变下表现出自恢复和温度扫描下的热可逆性。添加纤维素I纳米纤维后，其存储模量的高频平台比纯PB提高了19倍。CNPs作为多功能交联剂和纳米填料，在物理和化学上桥接三维网络水凝胶。提出了CNPs、聚乙烯醇和硼砂多重络合的合理机理，以了解三维网络与水凝胶性质之间的关系。(C) 2013 Elsevier Ltd.版权所有。
Cellulose nanoparticle (CNP) reinforced polyvinyl alcohol-borax (PB) hydrogels were produced via a facile approach in an aqueous system. The effects of particle size, aspect ratio, crystal structure, and surface charge of CNPs on the rheological properties of the composite hydrogels were investigated. The rheological measurements confirmed the incorporation of well-dispersed CNPs to PB system significantly enhanced the viscoelasticity and stiffness of hydrogels. The obtained free-standing, high elasticity and mouldable hydrogels exhibited self-recovery under continuous step strain and thermo-reversibility under temperature sweep. With the addition of cellulose I nanofibers, a 19-fold increase in the high-frequency plateau of storage modulus was obtained compared with that of the pure PB. CNPs acted as multifunctional crosslinking agents and nanofillers to physically and chemically bridge the 3D network hydrogel. The plausible mechanism for the multi-complexation between CNPs, polyvinyl alcohol and borax was proposed to understand the relationship between the 3D network and hydrogel properties. (C) 2013 Elsevier Ltd. All rights reserved.