Adsorption and desorption behavior of an anionic pyrene chromophore in sequentially deposited polyelectrolyte-dye thin films

Abstract

Alternating thin films of the anionic dye pyrenetetrasulfonic acid (4- PSA) and poly(allylamine hydrochloride) (PAH) were formed by the sequential deposition of 4-PSA and PAH from aqueous solution onto solid substrates. Film growth was followed by absorption spectroscopy, and the resulting polyelectrolyte-dye multilayer assemblies were characterized by using fluorescence spectroscopy, X-ray reflectivity, and atomic force microscopy (AFM) measurements. 4-PSA was successfully deposited in alternation with PAH when the ionic strength of the PAH solution was greater than 0.1 M. At each PAH adsorption step a given amount of previously adsorbed 4-PSA was extracted. The amount of dye released depen..