Electrochromic properties of PANI/TiO2 nanocomposites

• Main Author: Liu, Jing.
• Other Authors: Lu Xuehong
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Materials::Defence materials
• Online Access: http://hdl.handle.net/10356/38836
• Institution: Nanyang Technological University

In recent years, much research has been conducted on polyaniline‟s composites with various inorganic nanoparticles to find applications in electrochromic devices. In order to investigate the electrochromic(EC) properties of polyaniline incorporated with nanocrystalline TiO2 particles, we have successfully synthesized polyaniline/TiO2 nanocomposites by in situ oxidative polymerization in different TiO2 contents. The chemical structures and morphology of the nanocomposites were characterized via FT-IR, XRD and SEM/EDX as well as electrical conductivity. The results indicated that there was a strong interaction between polyaniline macromolecule and nanocrystalline TiO2 particles. The characterization revealed that the TiO2 nanoparticles were possibly encapsulated by the polyaniline segments. The electrochromic(EC) properties were studied by means of UV-Vis absorption analysis, optical contrast and response time. The coloration time reduced and the optical contrast of PANI initially decreased but then increased with increasing TiO2. The results demonstrated that the incorporation of TiO2 nanoparticles into the polyaniline has an oxidative effect on the polyaniline resulting from tunneling electrons from polymer backbone “jump” to the surfaces of nanoparticles due to electron withdrawing ability of TiO2. Further investigations can be focused on improving the dispersion of TiO2 nanoparticles into the react solution or to modify the surface properties of the nanoparticles by surfactants or coupling agents.