Nelson Andrew, Muir Benjamin W, Oldham James, Fong Celesta, McLean Keith M, Hartley Patrick G, Oiseth Sofia K, James Michael
Australian Nuclear Science and Technology Organisation, Menai, New South Wales 2234, Australia.
Langmuir. 2006 Jan 3;22(1):453-8. doi: 10.1021/la052196s.
Radio-frequency glow-discharge plasma polymer thin films of allylamine (AA) and hexamethyldisiloxane (HMDSO) were prepared on silicon wafers and analyzed by a combination of X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), X-ray reflectometry (XRR), and neutron reflectometry (NR). AFM and XRR measurements revealed uniform, smooth, defect-free films of 20-30 nm thickness. XPS measurements gave compositional data on all elements in the films with the exception of hydrogen. In combination with XRR and NR, the film composition and mass densities (1.46 and 1.09 g cm(-)(3) for AA and HMDSO, respectively) were estimated. Further NR measurements were conducted with the AA and HMDSO films in contact with water at neutral pH. Three different H(2)O/D(2)O mixtures were used to vary the contrast between the aqueous phase and the polymer. The amount of water penetrating the film, as well as the number of labile protons present, was determined. The AA film in contact with water was found to swell by approximately 5%, contain approximately 3% water, and have approximately 24% labile protons. The HDMSO polymer was found to have approximately 6% labile protons, no thickness increase when in contact with water, and essentially no solvent penetration into the film. The difference in the degree of proton exchange within the films was attributed to the substantially different surface and bulk chemistries of the two films.
在硅片上制备了烯丙胺（AA）和六甲基二硅氧烷（HMDSO）的射频辉光放电等离子体聚合物薄膜，并通过X射线光电子能谱（XPS）、原子力显微镜（AFM）、X射线反射率（XRR）和中子反射率（NR）相结合的方法进行了分析。AFM和XRR测量结果表明，薄膜厚度为20 - 30 nm，均匀、光滑且无缺陷。XPS测量给出了薄膜中除氢以外所有元素的组成数据。结合XRR和NR，估算了薄膜组成和质量密度（AA和HMDSO分别为1.46和1.09 g cm⁻³）。对与中性pH水接触的AA和HMDSO薄膜进行了进一步的NR测量。使用三种不同的H₂O/D₂O混合物来改变水相和聚合物之间的对比度。测定了穿透薄膜的水量以及存在的不稳定质子数。发现与水接触的AA薄膜膨胀约5%，含有约3%的水和约24%的不稳定质子。发现HDMSO聚合物有大约6%的不稳定质子，与水接触时厚度没有增加，并且基本上没有溶剂渗透到薄膜中。薄膜内质子交换程度的差异归因于两种薄膜在表面和本体化学性质上的显著不同。
