Zhang Fengxiang, Srinivasan M P
Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117576.
Langmuir. 2007 Sep 25;23(20):10102-8. doi: 10.1021/la0635045. Epub 2007 Aug 24.
A novel type of composite thin film consisting of gold nanoparticles (AuNPs) and polymide (PI) was fabricated through layer-by-layer (LBL) assembly. To fabricate such films, bare AuNPs and a poly (amic acid) bearing pendant amine groups, namely, amino poly (amic acid) or APAA, were synthesized and assembled in an LBL fashion. Without any organic encapsulation layer on their surface, AuNPs were bound directly to APAA chains at the amine sites; X-ray photoelectron spectroscopy study suggested that the binding was based on a combined effect of metal-ligand coordination and electrostatic interaction, with the former dominating over the latter. An approximately linear growth of the film started from the second layer of AuNP as revealed by the UV-vis spectroscopy, and the degree of particle aggregation was higher in the first AuNP layer than in the subsequent layers due to the differences in the density of binding sites. The resultant assembly was heated to imidize the APAA, thereby creating a robust composite structure.
通过层层（LBL）组装制备了一种新型的由金纳米颗粒（AuNP）和聚酰亚胺（PI）组成的复合薄膜。为了制备这种薄膜，合成了裸AuNP和带有侧链胺基的聚（酰胺酸），即氨基聚（酰胺酸）或APAA，并以LBL方式进行组装。在其表面没有任何有机封装层的情况下，AuNP在胺位点直接与APAA链结合；X射线光电子能谱研究表明，这种结合是基于金属-配体配位和静电相互作用的综合效应，前者占主导地位。紫外-可见光谱显示，从AuNP的第二层开始，薄膜呈现近似线性生长，并且由于结合位点密度的差异，第一层AuNP中的颗粒聚集程度高于后续层。将所得组装体加热以使APAA亚胺化，从而形成坚固的复合结构。
