engleski

Controlling the properties of poly(allylamine hydrochloride)/poly(acrylic acid) ultrathin multilayer films by varying the supporting anion

Polyelectrolytes are macromolecules (e.g. polymers) with dissociating functional groups which can carry positive or negative charge in solution. By alternating adsorption of positively and negatively charged polyelectrolytes on a charged surface, polyelectrolyte multilayers are formed. These nanocomposites have interesting properties and are applied in various scientific fields, mainly in biomedicine and pharmacology. In this study, ultrathin films have been fabricated on silicon wafers from layer-by-layer assembled poly(allylamine hydrochloride), PAH and poly(acrylic acid), PAA. Ellipsometry, tensiometry, and atomic force microscopy were used to investigate the influence of the supporting sodium salt of polyelectrolyte solutions on the build-up and properties of PAH/PAA multilayer. It was found that the properties of prepared PAH/PAA multilayers follow the Hofmeister series. Thus, film thickness, hydrophobicity, and surface roughness increase in the order fluoride < chloride < perchlorate. These results confirm that solely by choosing the electrolyte type, polyelectrolyte multilayers with various structures and properties can be obtained.

Polyelectrolytes ; Polyelectrolyte multilayers ; Ion specific effects

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