Modelling of spreading process: effect from hydrogen bonds

Lubricant spreading on solid substrates has drawn considerableattention not only for the microscopic wetting theory but also forthe dramatic application in head-disk interface of magnetic storagedrive systems. Molecular dynamic simulation based on acoarse-grained bead-spring model has been used to study such aspreading process. The spreading profiles indicate that the hydrogenbonds among lubricant molecules and the hydrogen bonds betweenlubricant molecules and polar atoms of solid substrates willcomplicate the spreading process in a tremendous degree. Thehydrogen bonds among lubricant molecules will strengthen thelubricant combination intensity, which may hinder most moleculesfrom flowing down to the substrates and diffusing along thesubstrates. And the hydrogen bonds between lubricant molecules andpolar atoms of solid substrates will confine the lubricant moleculesaround polar atoms, which may hinder the molecules from diffusingalong the substrates and cause precursor film to vanish.