MINIATURIZATION OF PATTERNS UNDER ATTRACTIVE TOP SURFACE INCASE OF INHOMOGENEOUS LIQUID THIN FILMS
10th October 2018, Wednesday, 04:30‐04:30 pm (25+5 mins), ChE Seminar hall
ABSTRACT:
In this numerical work, studied the change in length scale of patterns when inhomogeneous (viscosity is decreasing with decrease in film thickness), non-slipping thin liquid film with an air gap present between two homogeneous solid surfaces. Free energy of the system is due to Lifshitz van der Waals attractive force (between the film-air interface and bottom substrate-film interface) and polar attractive force (between the film-air interface and top substrate-air interface). Length scale of patterns depends on polar force and viscosity parameters (M,). Depending upon the position of top surface (d) and decay length () film experiences polar force in different stages of dewetting. At very low values of d (> ) or at higher values of , polar force interferes with the bottom dewetting and forms single hole in . Whereas at lower values of , film experiences polar force in hole growth face and forms more than one hole in . Large change in length scale of patterns can be observed at higher values of even though more number of holes formed at lower values of . At lower values of , maximum number of holes in will form when strength of polar force is moderate, position of top surface is at and when viscosity parameters are in spinodal range.