In this paper, the physical meaning of zero point of charge measured by acid-base potentiometric titration (PT) is discussed and it is considered to be zero point of net charge (ZPNC). The interrelations of ZPNC (pHZPNC), zero point of variable charge (pHZPVC), permanent charge density (σP), variable charge density (σV) and total net surface charge density (σT) are theoretically analyzed. The pHZPNC and σP of the nanoparticles of aluminum-magnesium hydroxide are determined by PT method. Effects of electrolyte and pH on various electrochemical parameters are investigated. In addition, effect of CO3^2^- on the results obtained via PT method is also studied.

Key words: POTENTIOMETRIC TITRATION, CHARGE DENSITY, NANOPHASE MATERIALS