Dynamic characteristics of ellipsoidal Janus drop impact on a solid surface

Abstract

Impinging Janus drops can be stably produced by adding a high-viscosity drop to a low-viscosity drop. Here, we investigate the dynamic features of bouncing Janus drops on a solid substrate for an exploration of the effects of the viscosity ratio, initial drop shape, and impact velocity on altering the hydrodynamics. Numerical results show that the low-viscosity component evolves into liquid alignment along the principal direction with the help of a preferential flow, thereby resulting in the partial detachment from the mother Janus drops. We establish a regime map of the separation ratio of the drop and discuss how the parameters affect the asymmetry in the bounce and separation behavior. The low-viscosity components can be more likely to be detached from Janus drops as the viscosity ratio, drop's ellipticity, and/or impact velocity increase. This phenomenon is explained by the residence time and breakup of symmetry in the horizontal momentum between the low- and high-viscosity components. The peculiar dynamic characteristics of the Janus drop can provide potential for various applications, such as liquid purification and separation.

A Study on the Dynamics of Compound Materials on Superhydrophobic Surfaces: Effects of Droplet’s Size and Shape

“…비습윤 표면(non-wettable surface) 위 다중물질 (compound material) 거동 조절은 결빙방지(anti-icing) [1], 3D 프린팅 [2], 자가세정(self-cleaning) [3,4], 약물 전달 [5], 연소 [6], 전염병 전파 [7], 에너지 하베스팅 (energy harvesting) [8], 그리고 액체 정화(liquid purification) [9] (macro-ridge) [15][16][17][18], 곡선 [19], 계층 표면 구조 [20,21], 액적형상 변화 [22][23][24][25]를 도입하여 체류시간을 변화시킬 수 있음을 증명하였다.…”