KINETICS OF ADSORPTION OF SELF-ASSEMBLED FILMS FROM DOPED POLY(O-ETHOXYANILINE)

The adsorption process of alternated, ultra-thin films of carboxymethy lcellulose (CMC) and HCl-doped poly(o-ethoxyaniline) onto glass substr ates via the self-assembly (SA) technique was studied using W-vis spec troscopy. The kinetics of adsorption for the Ist, 2nd, 5th and 10th bi layers consists of a first order process for polymer concentrations fr om 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 p robably occurs because at lower pHs the polymer is more strongly doped which promotes an increase in the electrostatic attraction of the pol ymeric molecules to the substrate.