The intensity of every peak in FTIR spectrum of polyaniline is increased, using concentrated HCL as dopant compared with diluted HCL as dopant. Can anybody tell me the reason ?
Usually polyaniline is made conducting via protonic acid doping e.g. HCl, or via oxidation either chemically or electrochemically. Polyaniline exists in a variety of protonation and oxidation forms. The most important form of polyaninline, green protonated emeraldine is produced by the oxidative polymerization of aniline in aqueous acids. When charges are removed from (or added to) a polymer upon chemical doping, geometric parameters, such as bond length and angles, change and reflected in the FTIR spectrum.