Finite Element Simulation of the Drying and Deformation Process of Polymer Solution Droplet on Substrates Using ALE Method

Abstract

In the drying process of polymer solution droplets on substrates, some coupling effects of several phenomena such as contact line receding, surface skin formation by viscosity change, gelation of contact line (self-pinning) and outward flow in a droplet, are important. For a droplet having large contact angle, the lubrication approximation for thin films cannot be applied. Here, we have made the finite element simulation for a drying polymer solution droplet having 90 degree contact angle on a substrate using ALE (Arbitrary-Lagrangian-Eulerian) moving boundary method with experimentally measured rheological and transformation properties of polystyrene/anisole polymer solution and solved the contact line receding, outward flow by surface tension, solute distribution, and the buckling of a surface skin, which reproduces the experimentally observed results.