- 作者: A. Kriaa,* N. Hamdi and E. Srasra
- 作者服務機構: Unite de recherche sur les materiaux, Institut National de recherche scientifique et technique, Tunis, BP 95-2050 Hammam lif, Tunisia
- 中文摘要: This paper deals with determining points of zero charge of natural and Na+-saturated mineral kaolinites using two methods: (1) acid-base potentiometric titration was employed to obtain the adsorption of H+ and OH- on amphoteric surfaces in solutions of varying ionic strengths in order to determinate graphically the point of zero net proton charge (PZNPC) defined equally as point of zero salt effect (PZSE); (2) mass titration curve at different electrolyte concentrations in order to estimate PZNPCs by interpolation and to compare with those determined by potentiometric titrations. The two methods involved points of zero charge approximately similar for the two kaolinites between 6.5-7.8, comparable to those reported previously and were in the range expected for these clay minerals. The comparison of potentiometric surface titration curves obtained at 25 °C and those published in the literature reveals significant discrepancies both in the shape and in the pH of PZNPCs values.
- 英文摘要: --
- 中文關鍵字: Kaolinite; Mass titration; Potentiometric titration; Point of zero net proton charge; Proton surface charge.
- 英文關鍵字: --