EFFECTS OF DIFFERENT ELECTROLYTES ON THE COLLOID STABILITY OF WATER-BASED INKS

摘要

In this paper, the colloidal properties of waterbased inks and the effects of Ca2+, Al3+, cationic surfactant and nonionic surfactant on the colloidal stability of water-based inks were studied. The results showed that the water-based ink dispersion were colloid stable solution. Adding calcium and aluminum ions could reverse the surface charge of ink particles from negative to positive and cause the ink particles to agglomerate obviously. Results also showed that Zeta potential changed from negative to positive and exceeded 20 mV at various pH levels owing to adsorption of hexadecyltrimethylammoniuM bromide (CTAB) on the surface of ink particles, but CTAB had little impact on the particle size. The addition of alcohol ethoxylate with an ethoxylation number of 7 (AEO-7) obviously decreased the Zeta potential of ink particles and made the ink particles to flocculate.