Kinetics of adsorption of self-assembled films from doped poly(o-ethoxyaniline)

The adsorption process of alternated, ultra-thin films of carboxymethylcellulose (CMC) and HCl-doped poly(o-ethoxyaniline) onto glass substrates via the self-assembly (SA) technique was studied using UV-vis spectroscopy. The kinetics of adsorption for the 1st, 2nd, 5th and 10th bilayers consists of a first order process for polymer concentrations from 10−4 to 10−2 M, with characteristic times of the order of 100 s, regardless of the solution pH in the range from 1 to 5. It was also observed that adsorption is faster and more effective for pH=1. This probably occurs because at lower pHs the polymer is more strongly doped which promotes an increase in the electrostatic attraction of the polymeric molecules to the substrate.