纳米颗粒调控流体润湿性微观实验观测

通过添加纳米颗粒调控油-水界面润湿性接触角是当前提高采收率技术研究的前沿热点。然而微观实验数据的缺乏使得纳米流体驱油机理始终存在争议。本文采用原子力显微镜的轻敲模式成像原理首次对液滴添加纳米颗粒后形成的纳米流体微观动态接触线进行测量。结果表明硅油液滴和正丙醇液滴在添加质量分数为5%的纳米石英颗粒后，微观接触角分别减小1.6°和0.9°，同时接触线在20 nm高度范围产生凸起结构，这与所添加纳米石英颗粒粒径一致。纳米凸起结构的产生为颗粒提高系统浸润性的结构分离压理论提供了直接的实验证据。

Microscopic Experimental Observation of Nanoparticle Regulated Fluid Wettability

Regulating the wettability contact Angle of oil-water interface by adding nanoparticles is a hot topic in the field of enhanced oil recovery technology. However, The lack of microscopic experimental data makes the mechanism of nanofluid displacement always controversial. In this paper, the microscopic dynamic contact lines of nanofluids formed by the addition of nanoparticles to droplets were measured for the first time using the tapping mode imaging principle of atomic force microscopy. The results showed that the microscopic contact angles of the completely wetting silicone oil droplets and n-propanol droplets were reduced by 1.6° and 0.9°, respectively, and the contact lines produced a convex bending within a thickness of 20 nm, that is consistent with the addition of nano-quartz particle size. The generation of convex nanobending structures provided direct experimental evidence for the structure disjoining pressure theory that particles enhance the wettability of the system.