Tunable safranine T release from LbL films of single/blend polyanions

Abstract

Loading and release behavior of a cationic dye, namely, safranine-T, through layer-by-layer (LbL) multilayered films of poly(diallyldimethylammonium chloride) (PDADMAC) and single/blend anionic polyelectrolytes (PEs), namely, poly(acrylic acid) (PAA), and poly(styrenesulfonate) (PSS), are described. The growths of PDADMAC/PSS-PAA multilayers and their safranine-T sorption behavior are monitored using the UV-Vis technique and discussed in terms of blend composition of anionic PEs and pH as well as their hydrophilicity and topography. The dye loading and desorption properties of the LbL films prepared from single/blend negatively charged PEs mainly depend on the interactions of PEs and safranine T. Strong interactions between PSS and safranine T result in a higher dye entrapping inside LbL films whereas either PAA-rich or single PAA-based LbL film exhibits larger dye desorption. A higher PSS content in the feed blend composition leads to an observable increase in theta(ave) and surface roughness whereas the use of PAA can yield a flatter surface due to its partially recomposed chain conformational structure at pH 11. Consequently, LbL multilayers obtained from single and blend polyanions can be considered as an encouraging material platform for the controlled release of charged species such as protein, drug, and dye. because of their tunable physicochemical and morphological properties as well as surface wettability.