Self-assembled multilayer films based on a Keggin-type polyoxometalate and polyaniline

• Published in: Journal of colloid and interface science Vol. 264; no. 1; pp. 176 - 183
• Main Authors: Wang, Yonghui, Guo, Caixin, Chen, Yanwei, Hu, Changwen, Yu, Wenhua
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.08.2003; Elsevier
• Subjects: Chemistry; Colloidal state and disperse state; Conductivity; Exact sciences and technology; General and physical chemistry; Layer-by-layer self-assembly; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Polyaniline; Polyoxometalate; Ultrathin multilayer films; Polyoxometalate; Conductivity; Ultrathin multilayer films; Polyaniline; Layer-by-layer self-assembly; Heteropolysalt; Self assembly; Electrical conductivity; Electrical properties; Multilayer; Polyaxametalate; Transition metal Complexes; Bilayer; Thin film; Conducting polymers; Tungsten complex; Molecular assembly; Preparation; Doped polymer; Aqueous solution; Aniline polymer
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/S0021-9797(03)00392-8

Multilayer ultrathin films were fabricated from partially doped polyaniline (PAN) and a Keggin-type polyoxometalate [ α-SiW 12O 40] 4− ( α-SiW 12) in aqueous solution via the layer-by-layer self-assembly technique and characterized by UV–vis, FTIR, and X-ray photoelectron spectra (XPS), ellipsometry, scanning electron microscopy (SEM), and atomic force microscopy (AFM). UV–vis spectroscopy shows that the absorbance values at characteristic wavelengths of the multilayer films increase almost linearly with the number of PAN/ α-SiW 12 bilayers, suggesting that the deposition process is regular and highly reproducible from layer to layer. FTIR and XPS spectra confirm the incorporation of α-SiW 12 and PAN into the films. Ellipsometric measurements show that the PAN/ α-SiW 12 bilayer thickness increases with the increasing PAN solution concentration. SEM and AFM images indicate that the film surface is relatively uniform and smooth. In addition, the electrical conductivities of the multilayer films doped with hydrochloric acid were also measured.