Unusual growth of polyelectrolyte multilayers by introduction of a rugged multilayer template and their unique adsorption behaviors

Pristine polyelectrolyte multilayers (PEMs) composed of poly(allylamine hydrochloride) (PAH) and poly(sodium 4-styrenesulfonate) (PSS) were treated with an anionic surfactant to prepare rough and porous templates formed by surfactant-induced polyelectrolyte (PE) desorption from pristine film. These templates served as a base substrate for the growth of fresh multilayers using the same polyelectrolyte pair. Growth solutions with or without NaCl salt were used for the formation of fresh multilayers. The growth behavior of fresh multilayers on rugged PEMs was much different than that of a conventional film. The fresh multilayers on templates showed both nonlinear and linear growth behaviors and their surface morphologies differed from those of the rugged template or the pristine film. Unique adsorption behaviors were also observed when PEs were adsorbed onto the templates. UV-Vis spectroscopy and atomic force microscopy (AFM) were employed to study the entire system. These results of the present study offer a unique perspective on the usual model of PEM growth, and provide an alternative route for construction of PEMs with different architectures.