Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084, China.
J Colloid Interface Sci. 2010 Aug 1;348(1):250-4. doi: 10.1016/j.jcis.2010.04.010. Epub 2010 Apr 13.
Spreading non-Newtonian liquids with non-power-law rheology on completely wetting surfaces are seldom investigated. This study assessed the wetting behavior of polydimethylsiloxane (PDMS), a Newtonian fluid, two carboxymethylcellulose (CMC) sodium solutions, a PDMS+2%w/w silica nanoparticle suspension and three polyethylene glycol (PEG400)+5-10%w/w silica nanoparticle suspensions (non-power-law fluids) on a mica surface. The theta(D)-U and R-t data for spreading drops of the six tested, non-power-law fluids can be described by power-law wetting models. We propose that this behavior is attributable to a uniform shear rate (a few tens to a few hundreds of s(-1)) distributed over the thin-film regime that controls spreading dynamics. Estimated film thickness was below the resolution of an optical microscope for direct observation. Approximating a general non-Newtonian fluid spreading as a power-law fluid greatly simplifies theoretical analysis and data interpretation.
在完全润湿的表面上扩展具有非幂律流变特性的非牛顿流体的研究很少。本研究评估了聚二甲基硅氧烷（PDMS）、两种羧甲基纤维素（CMC）钠盐溶液、一种 PDMS+2%w/w 二氧化硅纳米颗粒悬浮液和三种聚乙二醇（PEG400）+5-10%w/w 二氧化硅纳米颗粒悬浮液（非幂律流体）在云母表面上的润湿行为。六个测试的非幂律流体的扩展液滴的θ(D)-U 和 R-t 数据可以用幂律润湿模型来描述。我们提出，这种行为归因于在控制扩展动力学的薄膜区域内分布的均匀剪切速率（几十到几百 s(-1)）。估计的薄膜厚度低于光学显微镜的分辨率，无法直接观察。将一般的非牛顿流体扩展近似为幂律流体可以大大简化理论分析和数据解释。
