Fluoroalkylsilane monolayers formed by chemical vapor surface modification on hydroxylated oxide surfaces
Fluoroalkylsilane monolayers formed by chemical vapor surface modification on hydroxylated oxide surfaces
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DOI：
10.1021/la9809067
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发表时间：
1999-10-26
期刊：
影响因子：
3.9
通讯作者：
Takai, O
中科院分区：
文献类型：
--
作者：
Hozumi, A;Ushiyama, K;Takai, O
通过将具有羟基化表面氧化物的Si衬底暴露于氟烷基硅烷（FAS）蒸气中，制备了防水表面。由于这种化学蒸汽表面改性（CVSM）是基于有机硅烷分子和氧化物表面羟基之间的化学反应，在CVSM之前，用172 nm紫外光在空气中照射，使底物表面完全羟基化，直到表面的水接触角接近0度。然后在常压下，将底物暴露于FAS前体的蒸气中，即具有不同全氟烷基链长的三种FAS中的一种[CF3(CF2)(n)CH2CH2Si(OCH3)(3)，其中n = 0、5或7，分别称为FAS-3、FAS-13和FAS-17]。FAS分子与底物表面的羟基发生化学反应并吸附在其上，形成厚度小于2 nm的薄层，随着全氟烷基链长度的增加，底物表面的拒水性增强。FAS-3、-13和-17处理的基质最大水接触角分别约为86°、106°和112°。
Water-repellent surfaces have been prepared by exposing Si substrates with a hydroxylated surface oxide to fluoroalkyl silane (FAS) vapor. Since this chemical vapor surface modification (CVSM) is based on the chemical reaction between organosilane molecules and hydroxyl groups at the oxide surface, prior to CVSM, the substrate surface was completely hydroxylated by irradiating in air with a 172-nm ultraviolet light until the water contact angle of the surface became almost 0 degrees. Under atmospheric pressure, the substrate was then exposed to vapor of an FAS precursor, that is, one of three types of FAS having different perfluoroalkyl chain lengths [CF3(CF2)(n)CH2CH2Si(OCH3)(3), where n = 0, 5, or 7, referred to as FAS-3, FAS-13, and FAS-17, respectively]. The FAS molecules chemically reacted with the hydroxyl groups on the substrate surface and adsorbed onto it, forming a thin layer of less than 2 nm in thickness, The water repellency of the substrate surface increased with an increase in perfluoroalkyl chain length. The maximum water-contact angles of the substrates treated with FAS-3, -13, and -17 were ca. 86 degrees, 106 degrees, and 112 degrees, respectively.