Factors Affecting to the Viscosity of Montmorillonite/Water Suspension 1. Relationship between Electrical Conductivity and Viscosity in Aqueous Montmorillonite Suspensions

• Published in: Journal of the Clay Science Society of Japan (in Japanese) Vol. 46; no. 2; pp. 120 - 130
• Main Authors: SUZUKI, Keizo, SATO, Tsutomu, YONEDA, Tetsuro, ENOTO, Hiroyuki
• Format: Journal Article
• Language: English
• Published: The Clay Science Society of Japan 04.06.2007
• Subjects: aqueous suspension; aspect ratio; electrical conductivity; montmorillonite; viscosity
• ISSN: 0470-6455; 2186-3563
• DOI: 10.11362/jcssjnendokagaku1961.46.120

Montmorillonite samples were obtained from the suspension of Yamagata-bentonite with four purification processes to investigate underlying conditions which cause their viscosity. The samples were also treated repeatedly by 70% 2-propanol solution with different times to prepare the samples with different amounts of water soluble salts. Moreover, the treatments with sodium acetate-acetic acid solution (pH:5.0) and NaCl solution were conducted to dissolve Ca-carbonate minerals and to homo-ionize the samples. Electrical conductivity (relating to the amount of water soluble salts) and viscosity of the montmorillonite suspensions were measured for the samples with different pre-treatments. From the results of measurements, the following conclusions were obtained. 1. Viscosities of the montmorillonite suspension are negatively correlated with their electrical conductivities. Under the higher content of water soluble salts (higher electrical conductivity), viscosity of the samples is lower. 2. In the salt concentration of 2.5×10-6-2.5×10-4moll -1, zeta-potentials of the samples are almost constant. 3. Even under the same content of water soluble salts, the obvious difference in viscosity of the samples with four purification processes was observed. The order of viscosity among the samples was not changed even after treatments with sodium acetate-acetic acid solution (pH: 5.0) and Na C1 solution. Consequently, the difference in the viscosity, therefore, may not arise from the external chemical conditions such as content of water soluble salts and species of exchangeable cation. 4. The observed difference in viscosity among the samples would be attributed to the difference in aspect ratios or particle sizes (sizes in a-b plane) of montmorillonite in the samples with different purification processes.