Preparation of Iron-Containing Hectorite-Like Swelling Silicate

Abstract

Iron-containing hectorite-like layered silicate was synthesized by the reaction of LiF, Mg(OH)2, colloidal silica, and FeCl3 in aqueous suspension at 100 °C for 2 days. From X-ray diffraction and infrared spectroscopic analysis, the formation of hectorite-like layered silicate was shown. Dimethyldioctadecylammonium and 1,1′-dimethyl-4,4′-bipyridinium (methyl viologen) ions were intercalated by cation-exchange reactions into the interlayer space of the iron-containing silicate. The intercalated amounts of both cationic species were larger compared to iron-free layered silicate, showing increase in the layer charge density of the silicate by the incorporation of iron(III). The increase in the layer charge was thought to be derived from isomorphous substitution of silicon(IV) by iron(III) in the silicate layer. The structural iron(III) was reduced to iron(II) by reaction with sodium dithionite, which was shown by a color-change (yellow to green) and the increase in the intercalated amounts of dimethyldioctadecylammonium and 1,1′-dimethyl-4,4′-bipyridinium ions.

Application of Hectorite-Coated Silica Gel Particles as a Packing Material for Chromatographic Resolution

“…Coating of silica gel particles with a thin film of hectorite was carried out based on our recent report 29 . The molar ratio of LiF:MgCl2:SiO2:urea was 0.21:0.8:8.0:8.0 in the starting mixture, where the amounts of Li and Mg sources relative to the amount of SiO2 were decreased by 15% from the reported ratio of Li: Mg: Si of 1.4:5.6:8.0 32,33 . In the experiment, urea (2.16 g), MgCl2…”

A controlled spatial distribution of functional units in the two dimensional nanospace of layered silicates and titanates

“…Compared with the modification with organoammonium ions, the polymer intercalation has advantages; the interlayer expansion can be controlled by the amount of polymers; for the organoammonium case, the amount cannot be used to control the expansion due to the segregation. In order to control the interlayer expansion, clays with different layer charge densities 11,12,96 or alkylammonium ions with different molecular structures should be used. The use of polymers with varied molecular weight and branched structure is worth conducting to modify the structure and properties.…”

Photochromic Intercalation Compounds

“…Co.) [62,63], have advantages for the photochemical studies since natural clay minerals contain impurities, which gave colored clays. Synthetic analogues of smectite have been prepared in laboratory and used for the adsorption of dyes [19,[64][65][66][67].…”