1. The Interfacial Structure of Water on a Hydrophobic Surface - A Mechanistic Study
Yingxi Elaine Zhu, Dept. of Chemical & Biomolecular Eng., Univ. of Notre Dame, Notre Dame, IN
This research aims to understand the interfacial molecular structure and water transport at varied flow rates near the surfaces of varied hydrophobicity by complementary force-sensing and microscopic approaches.
To explore the interfacial structure at the water-surface interface, we study the morphology of polymer stain from evaporating a polymer aqueous droplet at surface. The contact line in an evaporating drop can stay pinned to form a single ring or can shrink in a discontinuous step-wise manner and generate multiple rings. With polymer at surface of controlled wettability, we show that a pinning-depinning interfacial flow generates new contact lines, which recede after depinning and are repinned at an internal precipitate ring as the dictated location of the next contact line. Each precursor ring is formed when polymer are trapped by an internal micro-stagnation flow.
Evaporation
Dewetting
Stagnation flow
Film rupture