与基板间相互作用对聚乙烯醇水凝胶摩擦行为的影响

选择分别与聚乙烯醇(PVA)水凝胶具有较强和较弱相互作用的基板, 研究水介质中PVA水凝胶在其表面的摩擦行为. 结果表明, 与具有弱相互作用的凝胶-玻璃板体系相比, 具有强相互作用的凝胶-铝板体系的摩擦力(f)较高, 且其粘弹-流体润滑转变速率(vf)较大, 用吸附-排斥模型对其进行了分析. 当滑动速率v

Effect of Interaction Between Gel and Substrate on the Frictional Behavior of Poly(vinyl alcohol) Hydro-gel

The friction behavior of polyvinyl alcohol(PVA) gel sliding against different substrate surface, i.e. glass plate and Aluminiumin(Al) plate in water was investigaed. The results reveal that the frictional stress(f) for Gel-Al system is higher than that of Gel-glass owing to the strong interaction between PVA gel and Al plate. At the same time, the elastic-hydrodynamic transition velocity(vf) for Gel-Al system is higher than that of Gel-glass system, which also supports the theoretical prediction. In slow sliding velocity region, the interaction between PVA gel and substrate seems no influence on the sensitivity of f to normal pressure. The vf for a system with weak interaction between gel and substrate, such as Gel-glass, will increase with the increase of normal pressure. However, vf for a system with strong interaction between gel and substrate, such as Gel-Al, seems insensitive to normal pressure. In the fast sliding velocity region, the liquid lubrication prevails and f∝(ηvP)1/2.