Dynamic Wetting Failure and Air Entrainment in Surfactant Solutions

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

Kumar 1434016 This research is focused on exploring dynamic wetting, which is the displacement of some fluid (for example, air) initially in contact with a solid surface by a liquid that advances over the surface. In coating processes the receding fluid is air, and its entrainment into the liquid can be catastrophic since stringent control of coating uniformity is required to ensure product integrity. Indeed, the onset of dynamic wetting failure remains one of the primary obstacles to improving upon current manufacturing speeds for products that require liquid-applied coatings. This is a proposal with a clear path for fundamental understanding to practical applications with economic impact. Understanding wetting failure, a process that is quite common in manufacturing materials with coatings, can have an impact in the coating industry. This is a proposal to study the failure of the wetting process when surfactant molecules are present in the liquid. While recent work considers Newtonian liquids without any surfactants, in practice most coating liquids do contain surfactants. However, despite the importance of surfactants in coating processes, there is little fundamental understanding of how surfactants influence dynamic wetting failure and air entrainment. The objective of this proposal is to advance this understanding using a combination of theory and experiment.