An initially spherical liquid droplet is located between two moving parallel surfaces (or walls). The shape of the droplet in contact with the solid surfaces is studied by applying continues pressure to the moving walls. An algorithm is developed to compute the contact angle and the wetting characteristics of the droplet on the surface under forced spreading . The system consisted of 6379 atoms which simulate a droplet 6 nanometer in diameter, two surfaces of two layer atoms and their surrounding ambient gas. In these simulations the properties of the droplet and the surfaces are varied by suitably changing the liquid and wall molecular parameters, and their effect on the contact angle is studied. The parameters include interatomic interaction energies, wall porosity, and the droplet molecular diameter. Results indicate a complex relationship between the contact angle and many of the surface and liquid parameters. Comparison with the previous works demonstrates properties similar to the corresponding wetting phenomena on hydrophilic and hydrophobic surfaces for the changes of fluid interfaces, and were consistent with experimental observations and macroscopic theory.
Journal: TechConnect Briefs
Volume: 3, Technical Proceedings of the 2007 NSTI Nanotechnology Conference and Trade Show, Volume 3
Published: May 20, 2007
Pages: 328 - 331
Industry sector: Sensors, MEMS, Electronics
Topics: Micro & Bio Fluidics, Lab-on-Chip