engleski

Polyelectrolyte multilayers on silica surfaces: effect of ionic strength and sodium salt type

The formation of polyelectrolyte multilayers on silica surfaces was investigated in the presence of binary 1:1 sodium salts (NaCl, NaBr and NaNO3) at various salt concentrations. The build-up of multilayers was monitored using electrophoretic light scattering and quartz crystal microbalance with dissipation monitoring techniques. As cationic polyelectrolyte poly(diallyldimethylammonium chloride) was used and as anionic poly(sodium 4-styrene sulfonate). The counterion specific formation of multilayers was observed at higher electrolyte concentrations and the more pronounced influence was observed in the case of nitrate and bromide than in the case of chloride salt. These results confirm that solely by adjusting the appropriate ionic strength and by choosing the electrolyte type, polyelectrolyte multilayers with various properties and structure can be obtained.

polyelectrolyte multilayers ; poly(diallyldimethylammonium chloride) ; poly(sodium 4-styrene sulfonate) ; silica ; sodium salts ; ionic strength ; zeta-potential ; QCM-D

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