EFFECT OF NANOSTRUCTURES AND ELECTROSTATIC INTERACTIONS ON MENISCUS SHAPE AND DISJOINING PRESSURE OF THIN LIQUID FILMS

Han Hu
Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA, USA

Christopher R. Weinberger
Drexel University, Philadelphia, PA 19104, USA

Ying Sun
Department of Mechanical Engineering and Mechanics Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA

DOI: 10.1615/TFESC1.fnd.012778
pages 959-962

键词 Disjoining pressure, meniscus shape, nanostructured surfaces, electrostatic interactions, molecular dynamics

摘要

A general model of meniscus shape and disjoining pressure for thin liquid films on nanostructured surfaces with both van der Waals and electrostatic interactions accounted for is developed based on the minimization of free energy, the Derjaguin approximation and the DLVO theory. This model is then verified with molecular dynamics simulations for a water-alumina system with square nanostructures of varying depth and film thickness. Electrostatic interactions are shown to enhance the disjoining pressure effect. The meniscus shape becomes more conformal with increasing nanostructure depth and decreasing film thickness. The disjoining pressure effect is enhanced with nanostructure depth and this effect weakens as film thickness increases.