Acta Chimica Sinica ›› 2001, Vol. 59 ›› Issue (5): 780-783. Previous Articles     Next Articles

Original Articles



  1. 中国科学院上海硅酸盐研究所.上海(200050);中国科学院高性能陶瓷与超微结 构国家重点实验室
  • 出版日期:2001-05-15 发布日期:2001-05-15

Effects of pH and salt concentration on the interaction between alumina surfaces in NaCl solutions

Sun Jing;Gao Lian   

  1. Shanghai Inst Ceram., CAS.Shanghai(200050)
  • Online:2001-05-15 Published:2001-05-15

Interaction between alumina surfaces has been measured using atomic force microscope (AFM). The effects of pH and electrolyte concentration of NaCl on the forec measurement were investigated. At low ionic strenght around 0.0003mol/L, the interaction behaves as long- tanged repulsive force. With the rising of salt concentration, the magnitude of the repulsive force decreases due to compression of the electric double layer. The measured double layer decay lengths were consistent with the theoretical values. The measured force curve of 0.000 3mol.L was forred with DLVO theory with condtant change and constant potential as 8.8mV. The pH value has great influence on the interaction magnitude. A t pH 7.90, the interaction force is attractive. The fitted constant charge data show the isoelectric point of alumina is at 8.2, which is consistent with the results obtained from the eletrophoretic mobility measurement .


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