Friction of Zwitterionic Hydrogel by Dynamic Polymer Adsorption

详细信息    查看全文

• 作者：Jamil Ahmed ; Tetsurou Yamamoto ; Honglei Guo ; Takayuki Kurokawa ; Takayuki Nonoyama ; Tasuku Nakajima ; Jian Ping Gong
• 刊名：Macromolecules
• 出版年：2015
• 出版时间：August 11, 2015
• 年：2015
• 卷：48
• 期：15
• 页码：5394-5401
• 全文大小：447K
• ISSN：1520-5835

文摘

A simplified model describing the sliding friction of hydrogel on solid surface by dynamic adsorption of the polymer chains is proposed on the basis of polymer adsorption鈥搑epulsion theory. This dynamic adsorption model is used to analyze the friction results of zwitterionic hydrogels sliding over glass substrates with different substrate wettability, hydrogel swelling degree, ionic strength, and pH of bath solution. The adsorption time 蟿_b of polymer strands is found to decrease with the increase in sliding velocity or the Weissenberg number as a result of stretching. The adsorption time 蟿_b⁰ and the adsorption energy U_ads at stress-free condition, which are characteristic for each friction system, are also estimated. Roughly, a master curve is observed for the normalized adsorption lifetime 蟿_b/蟿_b⁰ and the Weissenberg number, with less dependence on the adsorption energy and the bulk properties of the gels in the observed experimental conditions. Thus, the dynamic adsorption model successfully correlates the frictional behavior of hydrogels with the adsorption dynamics of polymer strands, which gives insight into the molecular design of hydrogels with predefined frictional properties for biomedical applications.