Adsorption of Congored in Cationic Langmuir- Blodgett Films : Spectroscopic Investigations

The present paper reports the incorporation of an anionic water soluble dye congo red (CR) in the cationic octadecylamine (ODA) Langmuir-Blodgett (LB) films. ATR-FTIR spectroscopy confirms the presence of CR molecules in the adsorbed LB films. The adsorption kinetics of the CR molecules onto ODA LB films have been demonstrated by UV-Vis absorption spectroscopy. Comparison of fitted curve of the reaction kinetics to that of the observed one reveals that the reaction kinetics between CR and ODA LB films is of first order kinetic process.