Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Blum, A. E. Articles by Eberl, D. D. Search for Related Content GeoRef GeoRef Citation

MEASUREMENT OF CLAY SURFACE AREAS BY POLYVINYLPYRROLIDONE (PVP) SORPTION AND ITS USE FOR QUANTIFYING ILLITE AND SMECTITE ABUNDANCE

US Geological Survey, 3215 Marine St., Boulder, CO 80303, USA

^* E-mail address of corresponding author: aeblum{at}usgs.gov

A new method has been developed for quantifying smectite abundance by sorbing polyvinylpyrrolidone (PVP) on smectite particles dispersed in aqueous solution. The sorption density of PVP-55K on a wide range of smectites, illites and kaolinites is ~0.99 mg/m², which corresponds to ~0.72 g of PVP-55K per gram of montmorillonite. Polyvinylpyrrolidone sorption on smectites is independent of layer charge and solution pH. PVP sorption on SiO₂, Fe₂O₃ and ZnO normalized to the BET surface area is similar to the sorption densities on smectites. -Al₂O₃, amorphous Al(OH)₃ and gibbsite have no PVP sorption over a wide range of pH, and sorption of PVP by organics is minimal. The insensitivity of PVP sorption densities to mineral layer charge, solution pH and mineral surface charge indicates that PVP sorption is not localized at charged sites, but is controlled by more broadly distributed sorption mechanisms such as Van der Waals’ interactions and/or hydrogen bonding. Smectites have very large surface areas when dispersed as single unit-cell-thick particles (~725 m²/g) and usually dominate the total surface areas of natural samples in which smectites are present. In this case, smectite abundance is directly proportional to PVP sorption. In some cases, however, the accurate quantification of smectite abundance by PVP sorption may require minor corrections for PVP uptake by other phases, principally illite and kaolinite. Quantitative XRD can be combined with PVP uptake measurements to uniquely determine the smectite concentration in such samples.

Key Words: Clay • Illite • Intercalation • Montmorillonite • Polyvinylpyrrolidone • PVP • Quantitative Mineralogy • Smectite • Surface Area

This article has been cited by other articles:

				J. Srodon and D. K. McCarty SURFACE AREA AND LAYER CHARGE OF SMECTITE FROM CEC AND EGME/H2O-RETENTION MEASUREMENTS Clays and Clay Minerals, April 1, 2008; 56(2): 155 - 174. [Abstract] [Full Text] [PDF]

				G. E. Christidis and I. Mitsis A NEW Ni-RICH STEVENSITE FROM THE OPHIOLITE COMPLEX OF OTHRYS, CENTRAL GREECE Clays and Clay Minerals, December 1, 2006; 54(6): 653 - 666. [Abstract] [Full Text] [PDF]