Analysis of superhydrophobic material performance based on molecular dynamics simulations

Abstract

Hydrophobicity of materials is governed by both surface chemical property and geometrical microstructure. Currently, hydrophobic materials are mainly researched and prepared by trial and error, and the hydrophobic property could not be predicted theoretically. This paper proposes using molecular dynamics simulation method to simulate the microscopic wettability of the materials and guide the preparation of the materials. Carboxylic acid modified cupric oxide superhydrophobic material was chosen as the studied material, and the influence of hydrophobic property was analysed by changing the carbon atom number and the coverage of carboxylic molecular chains. The results of the simulation were verified by experiments, and simulation and experiments showed good agreement. The results show that, within a certain range, the chain length and hydrophobicity of the material were positively correlated, and when the carbon chain length reached a certain point, hydrophobicity no longer increased. The coverage of carboxylic molecular chains affected its hydrophobic property too. In the Wenzel state, the contact angle increases with the increasing of the coverage. In the Cassie state, the hydrophobicity can be improved by reducing the coverage appropriately.