Keywords: Polyelectrolyte multilayers; Ground calcium carbonate; Salt concentration; Adsorption
This study investigated the effects of salt concentration in polyelectrolyte multilayering (PEM) treatment on the properties of ground calcium carbonate (GCC) and the mechanical strength of the filled paper with the PEM treated GCC. Polydiallyldimethyl-ammonium chloride (PDADMAC) and poly(sodium 4-styrene sulfonate) (PSS) were used as cationic and anionic polyelectrolyte, respectively, for the PEM treatment. The PEM treatment was performed in 0 - 0.1 M NaCl solutions. Polyelectrolyte multilayers could be formed without flocculation of the PEM treated GCC particles, which was confirmed by the zeta potential and particle size of GCC. The amount of polymer adsorbed onto GCC showed different behavior depending on salt concentration. At relatively higher salt concentration (0.1 M NaCl) in this study, more adsorption of polyelectrolytes occurred, which resulted in a thick multilayer on GCC. In addition, it provided strength improvement of the filled paper when the PEM treated GCC was used as filler. As a results, salt concentration during PEM treatment affected both of properties of the PEM treated GCC and mechanical properties of filled paper.
