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流体动态湿润在工业生产和高新技术的开发中有广泛应用,非牛顿流体动态湿润研究正处于起步阶段,并有着相对于牛顿流体更为实际的应用前景和价值。本文研究了一类具有复杂流变性的聚乙二醇的二氧化硅纳米颗粒分散体系的动态湿润特性。通过液滴铺展法得到了液滴半径随铺展时间的变化关系,以及动态接触角随接触线移动速度的变化关系的实验数据。实验结果表明,该类流体在云母表面上完全铺展,R～t关系符合Tanner定律,结合Starov的理论,分析R～t数据认为该类流体的中剪切速率阶段,即包含剪切增稠段的流变性对动态湿润有重要的影响。现有的动态接触角理论没有针对该类复杂流变流体的专用模型,研究发现分子运动理论模型不考虑黏性耗散,不仅适用于牛顿流体,对本文的θ_D～U数据同样能很好地描述,拟合参数符合物理意义。
Fluid dynamic wetting has been widely used in the industrial production and the development of high and new technology. The research on dynamic wetting of non-Newtonian fluid is in its infancy and has more practical application prospects and value compared with Newtonian fluid. In this paper, the dynamic wetting behavior of a series of polyethylene glycol-dispersed silica nanoparticle dispersions with complex rheology was studied. The relationship between the droplet radius and spreading time was obtained by the droplet spreading method and the experimental data of the relationship between the dynamic contact angle and the moving speed of the contact line were obtained. The experimental results show that this kind of fluid fully spreads on the surface of mica and the R ~ t relationship accorded with Tanner’s law. Combined with Starov’s theory, it is considered that the medium shear rate of this kind of fluid, namely the shear thickening section The rheology of dynamic wetting has a significant impact. The existing dynamic contact angle theory does not have a specific model for such a complex rheological fluid. It has been found that the theoretical model of molecular motion does not consider the viscous dissipation, not only for Newtonian fluids, but also for the θ_D-U data in this paper Description, fitting parameters in line with the physical meaning.