SANS studies on deformation mechanism of slide-ring gel
SANS studies on deformation mechanism of slide-ring gel
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DOI：
10.1021/ma050624v
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发表时间：
2005-07-12
期刊：
影响因子：
5.5
通讯作者：
Shibayama, M
中科院分区：
文献类型：
--
作者：
Karino, T;Okumura, Y;Shibayama, M
用小角中子散射（SANS）研究了“滑环”（SR）凝胶的变形机理。通过将α-环糊精（CD）分子偶联到由聚乙二醇和CD组成的聚轮烷链上制备SR凝胶。由于CD分子的中空结构，由呈8字形的CD分子构成的交联键可以沿着聚合物链滑动。一个正常的蝴蝶图案首次观察到在二维SANS等强度曲线的SR凝胶单轴变形下，其中正常的蝴蝶图案意味着在垂直于拉伸方向的方向上的长等强度图案。然而，通过增加交联密度或增加拉伸比，正常的蝴蝶图案改变为异常的蝴蝶图案，如在常规共价键合的化学凝胶中通常观察到的。的变形机制，以及之间的SR凝胶和共价键合的化学凝胶的交联不均匀性的差异进行了讨论，通过专注于SR凝胶的独特的架构。
The deformation mechanism of "slide-ring" (SR) gels was investigated with small-angle neutron scattering (SANS). The SR gels were prepared by coupling a-cyclodextrin (CD) molecules on polyrotaxane chains consisting of poly(ethylene glycol) and CD. Because of a hollow structure of CD molecules, the cross-links made of CD molecules in a figure-of-eight shape can slide along the polymer chain. A normal butterfly pattern was observed for the first time in two-dimensional SANS isointensity profiles for the SR gels under uniaxial deformation, where the normal butterfly pattern means a prolate isointensity pattern in the direction perpendicular to the stretching direction. However, by either increasing the cross-link density or increasing the stretching ratio, the normal butterfly patterns changed to abnormal butterfly patterns as are commonly observed in conventional covalent-bonded chemical gels. The difference in the deformation mechanism as well as the cross-linking inhomogeneities between the SR gels and the covalent-bonded chemical gels is discussed by focusing on the unique architecture of the SR gels.