Lossless, Passive Transportation of Low Surface Tension Liquids Induced by Patterned Omniphobic Liquidlike Polymer Brushes

Abstract

Surfaces enabling directional liquid transportation are of great interest for a wide range of applications such as water collection, microfluidics, and heat transfer systems. Surfaces capable of lossless, long-range passive transportation of low surface tension (LST) liquids using wettability patterned, liquidlike coatings with minimal contact angle hysteresis are reported. Lossless LST droplet travel distances over 150 mm are achieved, enabled by a two-phase transportation mechanism: morphological transformation from a bulge to a channel shape, followed by directional transportation along the asymmetrical wedge-shaped channel. The developed surfaces can split, merge, and precisely transport various low-surface tension liquids, including alcohols, alkanes, and solvents. The developed transportation strategy can also enhance LST liquid dropwise condensation through continuous removal of the condensate, even on horizontally positioned surfaces without the assistance of gravity.

Super‐Slippery Poly(Dimethylsiloxane) Brush Surfaces: From Fabrication to Practical Application

“…Copyright ©2019 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim. (c) Time‐lapsed images of a 45 μL n‐decane droplet transported along a wedge‐shaped PDMS channel assisted with liquid‐like PFPE as the background [27] . Copyright ©2021 Wiley‐VCH GmbH.…”

“…(h) Time-lapsed images of condensate droplets directional transported along the channel. [27] Copyright ©2021 Wiley-VCH GmbH. (i) Selfpropulsion of continuously formed highly wetting droplets on horizontal gradient quasi-liquid surface without any external energy input.…”

Droplet interface in additive manufacturing: From process to application

“…35 By developing a simple dip-coating strategy to prepare superhydrophobic nozzles, well-controlled generation and manipulation of tiny droplets were realized with improved precision of liquid transfer and decreased retention of sample liquid. [49][50][51] This simple but effective method could significantly improve the quality of parts 3D printed by material jetting.…”

Engineered Switchable‐Wettability Surfaces for Multi‐Path Directional Transportation of Droplets and Subaqueous Bubbles

“…[ 5 ] In particular, fluid transport on functional surfaces having Janus wettability enjoys advantages of fast transport speed, multi‐scale adaptability, and easy processing, [ 6 ] which is utilized in a range of practical applications and demonstrates remarkable performance in water/gas collection, [ 1a,7 ] heat transfer, [ 8 ] water splitting, [ 9 ] and condensate removal. [ 10 ] In general, these functional surfaces exhibit fixed wettability, limiting their use to transporting single‐phase fluid, namely liquid [ 11 ] or gas. [ 12 ] It is a rewarding challenge if the transportation of both water droplets and subaqueous bubbles can be achieved by one functional surface, bringing down the cost and expanding the applications.…”