Abstract: The adsorption of cetylpyridinium chloride(CPC) onto a ceramic glaze mixture composed of limestone, feldspar, quartz, kaolin, and antibacterial agent was studied. Both adsorption isothermals and the average particle zeta potential were investigated in order to understand the suspension stability as a function of pH, ionic strength, and surfactant concentration. The results show that under the optimal conditions such as pH value of 7 or 9, 0.01 mol/L of ionic strength and around critical micelle concentration(CMC) of surfactant, antibacterial ceramic glaze acquires fine dispersion stability. The adsorption of CPC on ceramic glaze particles is in accordance with Langmuir model in 0.01mol/L at pH=7 and pH=9. The adsorption of small amounts of cationic CPC onto the primarily negatively charged surfaces of the particles in the pH range of 7−9 produces strong attraction and flocculation due to hydrophobic interactions. High concentration of surfactant under 0.01 mol/L of salt provides high zeta potential, which produces a high stability.

Key words: surfactant; antibacterial glaze; adsorption isotheral; dispersion stability; zeta potential