All Title Author
Keywords Abstract

Physics  2014 

Use of ultrasound attenuation spectroscopy to determine the size distribution of clay tactoids in aqueous suspensions

DOI: 10.1021/la402478h

Full-Text   Cite this paper   Add to My Lib

Abstract:

The dispersion processes of aqueous samples of clay are studied using ultrasound attenuation spectroscopy. The attenuation spectra that are acquired in the frequency range $10-100$ MHz are used to determine the particle size distributions (PSDs) for different concentrations and ages of the clay suspensions. Our analysis, using equivalent spherical diameter (ESD) for circular discs under Stokes drag in samples of concentrations greater than 1.5\% w/v, shows that a substantial fraction of the aggregates in suspension are actually tactoids that are composed of more than one platelet. This is in contrast to the general belief that clay disperses into individual platelets in the concentration range where their suspensions exhibit glassy behavior. We conclude that the incomplete fragmentation of the clay tactoids arises from the rapid enhancement of the inter-tactoid Coulombic repulsion.

Full-Text

comments powered by Disqus

Contact Us

service@oalib.com

QQ:3279437679

微信:OALib Journal