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Infrared Absorption Evidence on Exchange Reaction Mechanism of Copper and Zinc with Layer Silicate Clays and Peat
Author(s) -
DeMumbrum L. E.,
Jackson M. L.
Publication year - 1956
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/sssaj1956.03615995002000030010x
Subject(s) - silicate , copper , peat , zinc , absorption (acoustics) , inorganic chemistry , layer (electronics) , chemistry , mechanism (biology) , infrared , geochemistry , geology , mineralogy , materials science , organic chemistry , composite material , ecology , biology , philosophy , physics , epistemology , optics
The degree to which cations which form weak bases are sorbed in excess of cations which form strong bases is shown to be about 10% in montmorillonite and 40% in peat. These excesses were accounted for by a special reaction mechanism which was revealed when layer silicate clays or peat fractions were examined by an infrared absorption technique. Copper and zinc saturation decreased the 2.8 micron hydroxyl absorption intensity of montmorillonite, vermiculite, and kaolinite, indicating a reaction with octahedral OH in the layer silicates. The larger OH peak of kaolinite at 2.7 microns was not affected. Also, the copper treatment yielded an additional pair of absorption peaks at 6.4 and 7.0 microns. Aluminum and iron treatment tended to increase the 2.8 micron peak slightly. Copper and zinc saturation of peat fractions resulted in numerous shifts in the double bond region of the spectrum, which were indicative of chelation with C = O and N = O groups.