Effect of CA-Montmorillonite Expansion on X-Ray Diffraction Intensities, Progress Report, HR-111, 1966

(1966) Effect of CA-Montmorillonite Expansion on X-Ray Diffraction Intensities, Progress Report, HR-111, 1966. Transportation, Department of

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Abstract

The most abundant clay mineral group in Iowa soils is montmorillonite, most commonly calcium-saturated (Hanway et al, 1960). The calcium montmorillonite-water system was therefore selected for detailed X-ray study. Montmorillonite is unusual among minerals in that it has an expanding lattice in the c direction. That is, upon wetting with water, the individual silicate layers separate to allow entry of water, and the mineral expands. Characteristics of this expansion are readily studied by means of X-ray diffraction: the X-ray diffraction angle gives the average layer-to-layer "d001" spacing for any given moisture condition; the sharpness of the diffraction peak is a measure of uniformity of the d001 spacing; and the intensity of the peak relates to uniformity of the d001 spacing and in addition to the electron density distribution within the repeating elements. The latter is embodied in the "structure factor".

Item Type: Departmental Report
Keywords: Chemical analysis, Clay minerals, Diffraction, Instruments for measuring expansion, Montmorillonite, X ray analysis
Subjects: Transportation
Transportation > Materials
Transportation > Materials > Gravel and aggregates
Transportation > Research
Transportation > Data and Information Technology
ID Code: 17274
Deposited By: Iowa DOT Library
Deposited On: 30 Jun 2014 12:36
Last Modified: 29 Jan 2015 21:09
URI: http://publications.iowa.gov/id/eprint/17274