Dynamic Responses in Nanocomposite Hydrogels
Dynamic Responses in Nanocomposite Hydrogels
复制标题
DOI：
10.1021/ma0517547
复制
发表时间：
2006-01
期刊：
影响因子：
5.5
通讯作者：
E. Loizou;P. Butler;L. Porcar;G. Schmidt
中科院分区：
文献类型：
--
作者：
E. Loizou;P. Butler;L. Porcar;G. Schmidt
通过流变学和小角中子散射（SANS）研究了一系列聚合物-粘土凝胶的剪切响应。凝胶具有相同的质量组成，但不同的聚合物分子量（Mw）。虽然长的聚合物链可以连接几个血小板，这是多功能的交联，非常短的聚合物链应该不能这样做，使我们能够探索桥接的结构和动力学响应的影响。增加凝胶中的聚合物Mw导致SANS数据中越来越强的各向异性，表明剪切取向的程度越来越大。然而，这种取向的相对增加伴随着相对较低的剪切稀化量。各向异性颗粒的简单解决方案通常通过颗粒与流动对齐而剪切变薄，例如允许它们更容易地滑过彼此。在连接的凝胶中，连接性的破坏也会导致剪切稀化。因此，逆关系…
The shear response of a series of polymer−clay gels has been investigated by means of rheology and small-angle neutron scattering (SANS). The gels have the same composition by mass but different polymer molecular weights (Mw). While long polymer chains can interconnect several platelets, which act as multifunctional cross-links, very short polymer chains should not be able to do so, allowing us to explore the effects of bridging on structure and dynamical responses. Increasing the polymer Mw in the gels leads to increasingly strong anisotropy in the SANS data, indicating a larger and larger degree of shear orientation. This relative increase in orientation, however, is accompanied by a relatively lower amount of shear thinning. Simple solutions of anisotropic particles usually shear thin by alignment of the particles with the flow, allowing them for example to slide past each other more easily. In a connected gel, breaking of the connectivity should also lead to shear thinning. Thus, the inverse relations...