Zeta potential analysis: effect of CPB-kaolinite to the growth of bacteria

Abstract

The formation of cetylpyridinium bromide (CPB) loaded onto natural kaolinite from Indonesia with different initial CPB concentration ([CPB]i) was studied through zeta potential analysis. From the data obtained, CPB molecules have been attached to the surface of kaolinite structure indicated by the changes of the zeta potential value of the modified kaolinite with CPB from negative charge to positive charge. In detail, as the concentration of CPB achieved its critical micelle concentration (CMC) level at ~0.9 mM, the sample with [CPB]i below CMC level show negative value of zeta potential and vice versa. Interestingly, there is no growth of bacteria at sample modified with CPB concentration above CMC level of CPB. Hence, the modified kaolinite was successful inhibit growth of bacteria at a certain amount of CPB molecules attached to the kaolinite surface.