Adsorption of poly(N-ethyl-4-vinyl pyridinium bromide) onto Langmuir-Blodgett films built up from amphiphilic polymers

The interaction of a strong cationic polyelectrolyte, poly(N-ethyl-4-vinyl pyridinium bromide), with Langmuir-Blodgett (LB) films built up from four m onolayers of amphiphilic derivatives of the alternating copolymers of malei c acid and alkenes (one of the monolayers was formed by the amphiphilic cop olymer containing pyrenyl groups as fluorescent labels) was examined. Trans formations of absorbance spectra and quenching of fluorescence of the LB fi lms were detected after their contact with aqueous solutions of the cationi c polyelectrolyte. These changes were attributed to the adsorption of poly( N-ethyl-4-vinyl pyridinium bromide) onto such films. The efficiency of this process was found to be rather sensitive to the variations in pH of the su rrounding medium: adsorption of the cationic polyelectrolyte onto the LB fi lms was pronounced in basic media while it became rather weak in acidic med ia.