TY - JOUR
T1 - Aqueous Drop-on-Drop Impact on Super-Repellent Surface
AU - Han, Xing
AU - Tang, Xin
AU - Zhao, Haibo
AU - Li, Jiaqian
AU - Li, Wei
AU - Wang, Liqiu
N1 - Funding Information:
The financial support from the Research Grants Council of Hong Kong (GRF 17204420, 17210319, 17204718, and 17237316 and CRF C1006‐20WF and C1018‐17G) is gratefully acknowledged. The work was also supported in part by the Zhejiang Provincial, Hangzhou Municipal, Lin'an County Governments, and Zhejiang Institute of Research and Innovation, the University of Hong Kong.
Publisher Copyright:
© 2021 Wiley-VCH GmbH
PY - 2022/1/5
Y1 - 2022/1/5
N2 - Antiliquid-accumulation on the surface is desired in practical applications. Super-repellency of the surface reduces the interaction between impacting drop and the surface effectively. However, for horizontal super-repellent surfaces, super-repellency is not enough for liquid removal when drops keep coalescing and remain on the surface. The interaction between impacting drop and static drop can further be beneficial for antiliquid-accumulation on the surface. Here, aqueous drop-on-drop impact on the super-repellent surface is studied. Weber number of impacting drop and offset distance between drops control impacting outcomes (coalescence or bouncing), while the viscosity of drops influences fluid dynamics after the coalescence. The efficiency of released excess surface energy transferred into mechanical energy during coalescence can be 18.9% for upcoalescence, which is much higher than the efficiency for downcoalescence or in-plane coalescence (≈6%) as reported in the literature. The bouncing between drops can reduce liquid accumulation on a super-repellent wafer remarkably (99.1 vol% reduction of accumulated liquid), being a promising method for liquid removal.
AB - Antiliquid-accumulation on the surface is desired in practical applications. Super-repellency of the surface reduces the interaction between impacting drop and the surface effectively. However, for horizontal super-repellent surfaces, super-repellency is not enough for liquid removal when drops keep coalescing and remain on the surface. The interaction between impacting drop and static drop can further be beneficial for antiliquid-accumulation on the surface. Here, aqueous drop-on-drop impact on the super-repellent surface is studied. Weber number of impacting drop and offset distance between drops control impacting outcomes (coalescence or bouncing), while the viscosity of drops influences fluid dynamics after the coalescence. The efficiency of released excess surface energy transferred into mechanical energy during coalescence can be 18.9% for upcoalescence, which is much higher than the efficiency for downcoalescence or in-plane coalescence (≈6%) as reported in the literature. The bouncing between drops can reduce liquid accumulation on a super-repellent wafer remarkably (99.1 vol% reduction of accumulated liquid), being a promising method for liquid removal.
UR - http://www.scopus.com/inward/record.url?scp=85120620693&partnerID=8YFLogxK
U2 - 10.1002/admi.202101565
DO - 10.1002/admi.202101565
M3 - Journal article
AN - SCOPUS:85120620693
SN - 2196-7350
VL - 9
JO - Advanced Materials Interfaces
JF - Advanced Materials Interfaces
IS - 1
M1 - 2101565
ER -