Friction of Gels. 5. Negative Load Dependence of Polysaccharide Gels
Friction of Gels. 5. Negative Load Dependence of Polysaccharide Gels
复制标题
凝胶的摩擦力。
DOI：
10.1021/jp992277v
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发表时间：
2000
影响因子：
3.3
通讯作者：
Y. Osada
中科院分区：
文献类型：
--
作者：
J. Gong;A. Y. Iwasaki;Y. Osada
研究了三种多糖凝胶琼脂糖、结冷胶和κ-卡拉胶在有氧和水条件下对玻璃板的滑动摩擦。这些凝胶的摩擦力随着在空气中施加的载荷的增加而略有增加，而随着在水中施加的载荷的增加而急剧增加。然而，当施加超过临界值的载荷时，结冷胶和κ-卡拉胶凝胶的摩擦力表现出明显的负载荷依赖性。观察到的特定现象似乎源于多糖凝胶网络的不稳定性。高负载导致部分交联的松散和/或溶解，并带来增加的流体动力水层，其在高负载下充当良好的润滑器。根据作者提出的摩擦排斥-吸附模型讨论了摩擦机理。
The sliding friction of three kinds of polysaccharide gels, agarose, gellan, and κ-carrageenan, against a glass plate has been investigated under aerobic and water condition. The frictional force of these gels slightly increases with the increase in the load applied in air, while it strongly increases with the load in water. However, when the load exceeding a critical value is applied, the frictional force of gellan gel and κ-carrageenan gel showed a pronounced negative load dependence. The observed specific phenomenon seems to be originated from the instability of the network of the polysaccharide gel. High loading leads to the loosing and/or dissolution in part of the cross-linkage and brings about an increased hydrodynamic water layer that serves as a good lubricator under the high load. The mechanism of friction was discussed in terms of the repulsion−adsorption model of friction proposed by the authors.