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Intercalation of Soil Clays with Dimethylsulfoxide
Author(s) -
Lim C. H.,
Jackson M. L.,
Higashi T.
Publication year - 1981
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1981.03615995004500020039x
Subject(s) - kaolinite , intercalation (chemistry) , clay minerals , dissolution , chemistry , mineralogy , solubility , slurry , nuclear chemistry , materials science , inorganic chemistry , organic chemistry , composite material
Clays from soils of temperate and equatorial regions, containing kaolinite and complexly interstratified phyllosilicates, were intercalated with dimethylsulfoxide (DMSO) for X‐ray diffraction (XRD) analysis. Washing the DMSO‐clay complex with 99% methanol permitted its mounting on a glass slide instead of a porous tile for XRD. Well‐resolved XRD peaks were obtained with Li‐DMSO treatment. Reflections at 10, 11.2, 14.2, and 18.2Å basal spacing established the presence of mica, coarse kaolinite, chlorite, and expandable 2:1 layer silicates, respectively. Several component minerals present were interstratified and did not give discrete diffraction peaks. Kaolinite with “intercalation disorder” (difficult to expand in DMSO) required a stepwise intercalation procedure that included grinding with CsCl. The grinding decreased the XRD intensity of the 11.2Å peak of the kaolinite‐DMSO complex. Decrease in the duration of grinding with CsCl from 15 min to two 3‐min periods, washings with 8 and 4 N KOAc to decrease Cs after the hydrazine treatment, and slurry‐mounting the clay‐DMSO intercalate on a glass slide and drying resulted in greater parallel orientation of the flakes, as shown by the more distinct and higher intensity XRD peaks than those obtained by earlier procedures. The improved intercalation procedure effectively replaced more Cs (99.5 vs. 96%) and imparted less solubility increase of the minerals (0.3‐5.6% less SiO 2 , 0.2‐4.9% less Al 2 O 3 , and 0.1‐0.3% less Fe 2 O 3 were extracted by 0.5 N NaOH and dithionite) than earlier procedures.