Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
ACS Appl Mater Interfaces. 2010 Dec;2(12):3544-54. doi: 10.1021/am100729j. Epub 2010 Nov 10.
The design of robust omniphobic surfaces, which are not wetted by low-surface-tension liquids such as octane (γlv=21.6 mN/m) and methanol (γlv=22.7 mN/m), requires an appropriately chosen surface micro/nanotexture in addition to a low solid-surface energy (γsv). 1H,1H,2H,2H-Heptadecafluorodecyl polyhedral oligomeric silsesquioxane (fluorodecyl POSS) offers one of the lowest solid-surface energy values ever reported (γsv≈10 mN/m) and has become the molecule of choice for coating textured surfaces. In this work, we synthesize and evaluate a series of related molecules that either retain the POSS cage and differ in fluoroalkyl chain length or that retain the fluorodecyl chains surrounding a linear or cyclic molecular structure. The solid-surface energy (γsv) of these molecules was estimated using contact angle measurements on flat spin-coated silicon wafer surfaces. Zisman analysis was performed using a homologous series of n-alkanes (15.5≤γlv≤27.5 mN/m), whereas Girifalco-Good analysis was performed using a set of polar and nonpolar liquids with a wider range of liquid surface tension (15.5≤γlv≤72.1 mN/m). The hydrogen-bond-donating, hydrogen-bond-accepting, polar, and nonpolar (dispersion) contributions to the solid-surface energy of each compound were determined by probing the surfaces using a set of three liquid droplets of either acetone, chloroform, and dodecane or diiodomethane, dimethyl sulfoxide, and water.
设计具有强大疏液性的表面，使其不被低表面张力液体润湿，如辛烷（γlv=21.6 mN/m）和甲醇（γlv=22.7 mN/m），需要选择适当的表面微纳结构，以及低固体表面能（γsv）。1H,1H,2H,2H-十七氟癸基多面体低聚倍半硅氧烷（氟癸基 POSS）提供了有史以来报告的最低固体表面能值之一（γsv≈10 mN/m），并且已成为涂覆纹理表面的首选分子。在这项工作中，我们合成并评估了一系列相关分子，这些分子要么保留 POSS 笼，氟烷基链长度不同，要么保留围绕线性或环状分子结构的氟癸基链。这些分子的固体表面能（γsv）是通过在平坦的旋涂硅晶片表面上进行接触角测量来估计的。Zisman 分析使用一系列正烷烃（15.5≤γlv≤27.5 mN/m）进行，而 Girifalco-Good 分析使用一组具有更宽液体表面张力范围的极性和非极性液体（15.5≤γlv≤72.1 mN/m）进行。通过使用一组丙酮、氯仿和正十二烷或二碘甲烷、二甲基亚砜和水的三个液滴探测表面，确定了每个化合物的固体表面能的氢键供体、氢键受体、极性和非极性（色散）贡献。
