Friction of gels. 6. Effects of sliding velocity and viscoelastic responses of the network
Friction of gels. 6. Effects of sliding velocity and viscoelastic responses of the network
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DOI：
10.1021/jp012380w
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发表时间：
2002-05-09
影响因子：
3.3
通讯作者：
Osada, Y
中科院分区：
文献类型：
--
作者：
Kagata, G;Gong, JP;Osada, Y
在纯水和盐溶液中的凝胶摩擦的速度依赖性进行了研究，以阐明与基板的界面相互作用的效果。当凝胶和基底是排斥的，摩擦力强烈地依赖于滑动速度，其中较高的法向压缩应变，更强的速度依赖性的摩擦。发现单位面积的摩擦力f遵循幂律，f与uppermance（β）成正比，其中指数β取决于法向压缩应变。这一结果表明，在排斥情况下的凝胶摩擦不能用简单的流体动力学机制来解释，由此预测f与uppermance（1.0）成正比。相反，在有吸引力的情况下，摩擦力表现出最大值的滑动速度的增加，这定性地符合我们先前提出的排斥吸附模型。
The velocity dependence of gel friction was investigated in pure water and in salt solutions to elucidate the effect of interfacial interaction with substrates. When the gel and the substrate were repulsive, the frictional force depended strongly on the sliding velocity, whereupon the higher the normal compressive strain, the stronger the velocity dependence of the friction. The frictional force per unit area,f, was found to follow a power law as f proportional to upsilon(beta), where the exponent, beta, depends on the normal compressive strain, This result shows that the gel friction in the repulsive case cannot be explained in terms of the simple hydrodynamic mechanism, from which f proportional to upsilon(1.0) is predicted. On the contrary, in the attractive case, the frictional force showed a maximum value with increase in the sliding velocity, which qualitatively coincides with our repulsion-adsorption model proposed previously.