Preparation of Alumina Pillared Synthetic Fluorohectorite with Specific Gallerey

Abstract

A solution of aluminum chloride hydroxide (Al₂C 1(OH)₅.2.4 H20) was added to a suspension of synthetic fluorohectorite in poly(vinyl alcohol) (PVA) (2.0 g of PVA and 1.0 g of synthetic fluorohectorite) by varying the volume of the solution: the resulting final concentration of the salt was in the range from 0.15 to 0.89 wt%. - The mixture was aged at 60 °C for 3 d followed by washing, drying, and calcination at 500 °C for 2 h. Varying the concentration of an aluminum chloride hydroxide solution was found to result in a systematic alteration of the interlayer distance of synthetic fluorohectorite pillared with alumina. The interlayer distance increased from 8.9 to 19.3A with increasing resultant final concentration of an aluminum chloride hydroxide from 0.15 to 0.89 wt%. Varying the concentration of PVA solution was also found to result in a systematic alteration of the distance. In contrast, the distance of alumina pillared synthetic fluorohectorite prepared in the absence of PVA was independent of the concentration of aluminum chloride hydroxide, i. e., ca.9Å. It was estimated that the lateral distance of alumina pillared synthetic fluorohectorite decreased from 20 to 12Å with increasing interlayer distance from 8.9 to 19.3Å.
These findings and the simulation may lead us to conclude that the presence of PVA during pillaring and varying the concentration of aluminum chloride hydroxide are necessary for controlling both the interlayer distance and lateral distance of alumina pillared synthetic fluorohectorite.