INTERCALATION OF SUGAR ALCOHOLS INTO THE INTERLAYER OF MONTMORILLONITE BY WET AND DRY PROCESSES

Abstract

Organic and inorganic complexes are formed by the intercalation of ethylene glycol and glycerol into the interlayer of montmorillonite. Glycerol and ethylene glycol have the molecular formula C 2 H 6 O 2 and C 3 H 8 O 3 , respectively, and the general formula is C n H 2(n+1) O n . This formula represents a sugar alcohol group: erythritol for n = 4, xylitol for n = 5, sorbitol for n = 6, and so on. Complexes were produced by a wet process, in which erythritol, xylitol and sorbitol solutions, and montmorillonite, were mixed to a paste; and by a dry process, in which montmorillonite and erythritol, xylitol and sorbitol, in the solid state, were mixed by automatic agate mortar. X-ray diffraction, FT-IR and X-ray photoelectron spectroscopy analyses of the resulting complexes showed that erythritol, xylitol and sorbitol were intercalated into the interlayer of montmorillonite in both wet and dry processes. The resulting complexes also showed an increase in the basal spacing with increasing n (or molecular weight or carbon chains). The difference between the wet and dry processes lies in the d-spacing in each montmorillonite-sugar alcohol system. The d-spacing of the complexes formed by the wet intercalation process were about 0.4 nm larger than those formed by the dry intercalation process. This is the length of the longest part of the water molecule. In the wet process, the sugar alcohols were intercalated with water molecules, and the montmorillonite swelled, while it expanded in the dry process.