期刊
PHYSICAL REVIEW E
卷 62, 期 6, 页码 8308-8313出版社
AMERICAN PHYSICAL SOC
DOI: 10.1103/PhysRevE.62.8308
关键词
-
Measurements are described using small angle coherent x-ray scattering and small angle dynamic light scattering of motion in fumed silica aggregates suspended in a poly(dimethyl siloxane) melt. At rest, this system develops weakly bound superstructures that are disrupted by mechanical stirring or thermal treatment. The observed relaxation rates correspond to a combination of liquidlike diffusion and a structural relaxation (flocculation) whereby the diffusing silica aggregates recombine into larger agglomerates at long times. Both processes are diffusion controlled. Two samples are investigated. The first, in which the silica is hydrophilic, is a highly viscous liquid for which the respective rate coefficients are about 5 X 10(-14) cm(2)s(-1) and 2 X 10(-15) cm(2)s(-1). The second sample, in which the silica surface is hydrophobic, is a thixotropic paste. The same aging mechanism in the diffusion is also observed, but with much slower rate constants, 2 X 10(-15) cm(2)s(-1) and 9 X 10(-16) cm(2)s(-1), respectively.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据