表面自由基链转移反应制备润湿性可控聚合离子液体薄膜

Preparation of poly(ionic liquid) films with tunable wettability through surface radical chain-transfer reaction

采用分子自组装技术在羟基化的单晶硅表面制备了3-巯丙基三甲氧基硅烷单分子层,然后以偶氮二异丁腈为引发剂,通过表面自由基链转移反应在基底表面引发了离子液体单体1-烯丙基-3-甲基咪唑氯化物([AMIM]Cl)的原位聚合,通过"直接离子交换"法改变了薄膜表面的对阴离子.用X射线光电子能谱仪(XPS)分析了聚合物薄膜表面典型元素的化学状态,用原子力显微镜(AFM)观察了薄膜的表面形貌,用椭圆偏光仪测量了薄膜的厚度,并用接触角仪对薄膜表面的静态水接触角进行了测量.结果表明,聚合离子液体薄膜成功接枝到了硅片表面,通过对离子的交换实现了薄膜表面润湿性的可控转变.

The self-assembled monolayer of 3-mercaptopropyl trimethoxysilane is fabricated on hydroxylated monocrystalline silicon substrates by a molecular self-assembly technique.Then 1-allyl-3-methylimidazolium chloride（Cl） is initiated to polymerize on the silicon substrates in-situ by using azobisisobutyronitrile（AIBN） as initiator through surface radical chain-transfer reaction.The anions in the films are exchanged by ＂direct anion exchange＂.The chemical states of some typical elements in the polymer films are analyzed using X-ray photoelectron spectroscopy（XPS）,the morphology of the thin films is observed using an atomic force microscope（AFM）,and the thicknesses of the films are measured with a spectroscopic ellipsometer.The static water contact angles are determined using static water contact angle goniometer.The results show that the poly（ionic liquid） films are successfully grafted on the silicon substrates.Moreover,controllable wettability of the films can be achieved by exchanging their counteranions.