Puniredd Sreenivasa Reddy, Srinivasan M P
Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117576.
Langmuir. 2006 Apr 25;22(9):4092-9. doi: 10.1021/la052505e.
Layer-by-layer covalent assembly of an oligoimide on an anhydride- derivatized silicon dioxide surface is investigated using supercritical carbon dioxide (SCCO2) as the depositing medium. The deposited films were characterized by X-ray photoelectron spectroscopy (XPS), ellipsometry (VASE), UV-visible spectroscopy, electrochemical impedance spectroscopy, nano indentation, and atomic force microscopy (AFM) and the properties of the films compared with those of an oligoimide deposited on amine-derivatized surfaces. Films formed on the anhydride surface are more uniform and stable possibly because the silane precursor for the anhydride is anchored to the surface through two (-Si-O-Si-) tripods. XPS results indicate that the interfacial reaction resulting in amide formation is almost complete in the case of the anhydride, but not in the case of the amine. We infer that the twin tripods linking the anhydride group to the surface may have improved the accessibility of the functional groups for immobilization of the next layer, thereby contributing to the better quality.
使用超临界二氧化碳（SCCO2）作为沉积介质，研究了低聚酰亚胺在酸酐衍生化二氧化硅表面上的逐层共价组装。通过X射线光电子能谱（XPS）、椭偏仪（VASE）、紫外可见光谱、电化学阻抗谱、纳米压痕和原子力显微镜（AFM）对沉积的薄膜进行了表征，并将薄膜的性能与沉积在胺衍生化表面上的低聚酰亚胺的性能进行了比较。在酸酐表面形成的薄膜更均匀、更稳定，这可能是因为酸酐的硅烷前体通过两个（-Si-O-Si-）三脚架锚定在表面上。XPS结果表明，在酸酐的情况下，导致酰胺形成的界面反应几乎完成，但在胺的情况下则没有。我们推断，将酸酐基团连接到表面的双三脚架可能提高了官能团对下一层固定的可及性，从而有助于提高质量。
