Microgroove-structured liquid-like surface for liquid discrimination  

用于液体区分的微沟槽结构类液体表面

作　　者：Shouzheng Jiao Peng Cheng Hua Lai Zhongjun Cheng Yuyan Liu Lei Jiang 焦守政;程鹏;来华;成中军;刘宇艳;江雷(State Key Laboratory of Urban Water Resource and Environment,School of Chemistry and Chemical Engineering,Harbin Institute of Technology,Harbin 150001,China;CAS Key Laboratory of Bio-Inspired Materials and Interfacial Science,Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]State Key Laboratory of Urban Water Resource and Environment,School of Chemistry and Chemical Engineering,Harbin Institute of Technology,Harbin 150001,China [2]CAS Key Laboratory of Bio-Inspired Materials and Interfacial Science,Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Science China Materials》2024年第11期3719-3726,共8页中国科学（材料科学）（英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC,22075061);State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(2022TS37)。

摘　　要：Discriminating between different liquids using surfaces with special wettability holds significant implications for both fundamental research and practical applications.However,current differentiation surfaces still struggle with challenges such as complex microstructure design,a limited detection range,and poor stability.In this study,we present a new platform for droplet discrimination achieved through a combination of groove structures and a liquid-like polydimethylsiloxane(PDMS)brushes coating.The PDMS brushes coating exhibits excellent stability and low adhesion across a wide range of liquids with surface tensions ranging from 27.5 to 72.8 mN/m,while the groove structure provides distinct energy barriers for droplet sliding.Consequently,liquids with varying surface tensions can be effectively discriminated,as evidenced by the increased sliding angles(SAs)observed as liquids with lower surface tension moving across the groove.Furthermore,we utilized a three dimensional(3D)model of the droplet developed using Surface Evolver,and conducted energy variation calculations during droplet sliding across the groove to analyze the SA differences among liquids with different surface tensions.Additionally,we proposed two simple differentiation platforms that successfully demonstrated effective droplet discrimination.This work introduces a novel strategy for droplet discrimination,offering innovative ideas for the design of functional surfaces.These findings may potentially be applied in other fields involving droplet manipulation,such as droplet-based microchemical reactions and bio-detection.利用具有特殊润湿性的表面来区分不同液体,对基础研究和实际应用都具有重要意义.然而,目前用于液滴区分的表面仍然面临着复杂的微结构设计、有限的检测范围和较差的稳定性等挑战.在本研究中,我们提出了一种新型的液滴区分平台,该平台通过结合微沟槽结构和液态类PDMS刷涂层来实现.PDMS刷涂层对表面张力为27.5到72.8mN/m范围内的各种液体都表现出卓越的稳定性和较低的粘附性,而微沟槽结构则为液滴滑动提供了能量壁垒.当表面张力较低的液体滑过凹槽时,会产生更高的滑动角(SA),因此,不同表面张力的液体能被有效区分.我们利用Surface Evolver设计了液滴运动的三维模型,进一步对液滴运动过程中的能量变化进行了计算,以分析不同表面张力液体之间SA差异的原因.此外,我们还设计了两种简单的液滴区分平台,成功地实现了不同液滴的区分.这项工作提出了一种新颖的液滴区分策略,为功能化表面的设计提供了思路.这些发现可能会应用于涉及液滴操作的其他领域中,例如液滴微化学反应和生物检测.

关 键 词：liquid discrimination liquid-like surface microgroove-structured PDMS brushes energy barrier 

分 类 号：TB306[一般工业技术—材料科学与工程]