Colloid silica viscosity determined by the particle sedimentation method

• Autorzy: Adamczyk Z. , Siwek B. , Zembala M.
• Języki publikacji: EN

Abstrakty

EN

Viscosity of colloid silica was determined as a function of the volume fraction varied between 0 and 0.37. A new method of viscosity measurements was applied, based on determination of particle sedimentation velocity. The sedimentation velocity was calcu-lated from the kinetics of irreversible adsorption (deposition) of melamine latex particles (particle size 1.7 and 3.6 pirn) at silanized mica. Deposition kinetics was determined in the sedimentation cell using the direct microscope observation technique. This method is significantly more accurate, especially in the region of low shear rates, than the classical viscosity measurements exploiting commercial viscometers. It was found that colloid silica viscosity increased more rapidly with increased volume fraction than predicted by the classical Batchalor and Dougherty-Krieger models. The deviation has been attributed to the secondary electroviscous effect stemming from the electrostatic interactions among sil-ica colloid particle. This has quantitatively been interpreted in terms of the effective hard particle concept used previously to describe densities of particle mono-layers. Explicit de-pendence of the effective particle volume on the double-layer thickness has also been given.

Słowa kluczowe

EN

colloid; silicate; viscosity; sedimentation

PL

krzemionka; koloid; lepkość; sedymentacja

• Wydawca: Centrum Upowszechniania Nauki PAN
• Czasopismo: Bulletin of the Polish Academy of Sciences. Chemistry
• Rocznik: 2000
• Tom: Vol. 48, No. 3
• Strony: 231--242
• Opis fizyczny: Bibliogr. 23 poz.

Twórcy

autor

Adamczyk Z.

autor

Siwek B.

autor

Zembala M.

• Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Kraków, Poland (Instytut Katalizy i Fizykochemii Powierzchni PAN)