IONIC EFFECTS OF SODIUM-CHLORIDE ON THE TEMPLATED DEPOSITION OF POLYELECTROLYTES USING LAYER-BY-LAYER IONIC ASSEMBLY

A new method for the patterning of ionic layer-by-layer assembled film s with micron-sized features is presented. Self-assembled monolayers ( SAMs) were used as templates to direct the deposition of sulfonated po lystyrene (SPS) and poly(diallyldimethylammonium chloride) (PDAC) mult ilayers onto a surface. Both polyelectrolytes were assembled electrost atically from dilute solutions (10 and 20 mM on a repeat unit basis) w ith varying amounts of sodium chloride. The ionic content was varied f rom 0 to 4 M NaCl. The optimal conditions for templating were found at moderate salt contents. At high salt contents (greater than or equal to 1 M NaCl) the templating behavior of the chemically patterned SAM s urface completely reversed due to electrostatic screening and dehydrat ion of an oligo(ethylene glycol)surface, indicating that ionic strengt h can be used to dramatically alter polyion deposition behavior on the functionalized surface.