Fabrication and Electrochemical Behaviors of Thin Films of Polyaniline by Langmuir-Blodgett Technique and Electropolymerization

在加有苯胺的亚相上，铺展硬脂酸分子，在气液界面上可形成苯胺－硬脂酸Ｌａｎｇｍｕｉｒ膜．随膜压增大至５．０×１０￣（－６）Ｎ时，苯胺与硬脂酸间的氢键会发生重排，形成另外一种构型的Ｌａｎｇｍｕｉｒ膜，分子所占面积减小，膜增加一个苯环的厚度．将膜转移到ＳｎＯ＿２导电玻璃基底上，制成硬脂酸－苯胺Ｌａｎｇｍｕｉｒ－Ｂｌｏｇｄｅｔｔ膜，经电化学氧化，苯胺可聚合成薄膜。膜夹在两层硬脂酸分子间，它的电化学行为不仅受到离子膜中传输过程的影响，同时受到硬脂酸极性亲水端（－ＣＯＯ￣－）的作用．Hydrogen-bond between stearic acid and aniline in subphase lead to Langmuirmonotayers of stearic acid-aniline,the molecular area of stearic acid-aniline is 26 nm￣2.With surfacepressure increased into 50 mN/M,the hydrogen-bond would be rearranged ,aniline moleculartransales into vertical from horizontal,surface pressure decreased quickly. A new kind of Langmuirmonolayer is formed instead of collapse,it's molecular area decreases into 24 nm￣2 and thicknessincreases with 0.25 nm. After electroreduction of L-B films depeited onto the surface ofSnO_2 electrode ,anilne layers between two stear acid matix could be polymerized into thin films ofpolyanilne.The structu re of thin films has ben studied by small angle X-ray scattering.Theelectrochemical properties of such thin films are very different from the films of polyaniline preparedby others methods.It's properties is not only effected by the proceed of ion transport,also by thehydrophilic grounp(-COO￣-)of stearic acid.作者联系地址：厦门大学化学系，厦门大学固体物理化学表面国家重点实验室, 北京理工大学化工与材料学院Author's Address: Department of Chemistry of Xiamen University,State Key Laboratory for Physical Chemistry of the Solid Surface,Xiamen 361005Zhang YunhongUniversity of Science and Technology Beijing,Beijing10008

Electrocatalytic Oxidation of Methanol on the Stearate Nickel L B Film

硬脂酸镍Ｌ－Ｂ膜电极对甲醇具有良好的电催化作用．膜中镍离子主要以－ＣＯＯＮｉ（ＯＨ）形式存在．电催化过程受ＯＨ－浓度的影响，也涉及甲醇分子在膜内的穿透．The stearate nickel L B films is good electroacatlyst for the oxidation of methanol MeOH in alkaline. The electrochemical behaviors of stearate nickel L B films is affected by the concentration of KOH. The rate of quantity of mickel ion and stearic acid in L B films is 1∶1, which means that the nickel ion may exist in -COONi(OH) form. The electrocatalytic process is influenced by the concentration of OH - , it involves the penetration of MeOH into the films. The oxidative currents of MeOH are linearly dependent on the bulk concentration.作者联系地址：固体表面物理化学国家重点实验室厦门大学化学系,北京理工大学化工与材料学院Author's Address: Dept. of Chem., Xiamen Univ., State Key Lab. for Phy. Chem. of the Solid Surf., Xiamen361005 Zhang Yanhong Univ. of Sci. and Tech. Beijing, Beijing 10008