Hectorite Surface area

The mesoporous materials produced from a precursory hectorite synthesized at 150°C had a total specific surface area of 848 m g a pore volume of 0.98 cm g and an average pore diameter of 46 5, values which are significantly higher than those of conventional pillared clays. 

Figure 2. Variation of the proton relaxation rate Tj 1 vs. the solid content (Cf) in water for various smectites. The contour (external) surface area of hectorite is ca 80 m2/g, the average number of sheets within a tactoid being about 10. (Reprinted with permission from ref 7. Copyright 1982 Academic.)...

Ca2 - and K+-hectorite, barasym at pH = 9 and Ca2 -laponite. For these clays the fluorescence intensity decreases with loading, following Perrin s law. Effective surface areas in aqueous suspension are estimated for the first time with Na+-hectorite as a reference. The second category is composed of Na+- and K+-laponite and barasym at pH= 7 A minimum in the... 

Pillared montmorillonite (and hectorites) have thermal stability in air that does not exceed 800°C. In contrast, the ACH-rectorites under study after calcination at 800°C, retain their pillared structure (Fig. 3) and more than 902 of their initial surface area. As a result, after calcining at 800°C/5h, only minor changes in the cracking properties of the two ACH-rectorites are observed. Table 2. 

Farmer, V. C., 1958. The infrared spectra of talc, saponite, and hectorite. Min. Mag. 31 829- 845. Farrar, D. M., 1963. The use of vapour pressure and moisture content measurements to deduce the internal and external surface area of soil particles. J. Soil. Sci. 14 360-371. 

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