材料科学
接触角
弹性体
复合材料
薄膜
硅氢加成
基质(水族馆)
图层(电子)
高分子化学
化学工程
纳米技术
化学
催化作用
海洋学
地质学
工程类
生物化学
作者
Thierry Thami,Michel Ramonda,Lynda Ferez,Valérie Flaud,Eddy Petit,Didier Cot,Bertrand Rebière,Bruno Ameduri
出处
期刊:Langmuir
[American Chemical Society]
日期:2022-11-09
卷期号:38 (46): 14140-14152
标识
DOI:10.1021/acs.langmuir.2c02109
摘要
The design of hydrophobic surfaces requires a material which has a low solid surface tension and a simple fabrication process for anchoring and controlling the surface morphology. A generic method for the spontaneous formation of robust instability patterns is proposed through the hydrosilylation of a fluoroalkene bearing dangling chains, Rf = C6F13(CH2)3-, with a soft polymethylhydrosiloxane (PMHS) spin-coated gel polymer (0.8 μm thick) using Karstedt catalyst. These patterns were easily formed by an irreversible swelling reaction due to the attachment of a layer to various substrates. The buckling instability was created by two different approaches for a gel layer bound to a rigid silicon wafer substrate (A) and to a soft nonswelling silicone elastomer foundation (B). The observations of grafted Rf-PMHS films in the swollen state by microscopy revealed two distinct permanent patterns on various substrates: dotlike of wavelength λ = 0.4-0.7 μm (A) or wrinkle of wavelength λ = 4-7 μm (B). The elastic moduli ratios of film/substrate were determined using PeakForce quantitative nanomechanical mapping. The characteristic wavelengths (λ) of the patterns for systems A and B were quantitatively estimated in relation to the thickness of the top layer. A diversity of wrinkle morphologies can be achieved by grafting different side chains on pristine PMHS films. The water contact angle (WCA) hysteresis of fluorinated chain (Rf) was enhanced upon roughening the surfaces, giving highly hydrophobic surface properties for water with static/hysteresis WCAs of 136°/74° in the resulting wrinkle (B) and 119°/41° in the dotlike of lower roughness (A). The hydrophobic properties of grafted films on A with various mixtures of hexyl/fluoroalkyl chains were characterized by static CA: WCA 104-119°, ethylene glycol CA 80-96°, and n-hexadecane CA 17-61°. A very low surface energy of 15 mN/m for Rf-PMHS was found on the smoother dotlike pattern.
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