Detail of "1318-93-0"

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Direct measurement of the relation between interlayer force and interlayer distance in the swelling of montmorillonite

Direct measurement of the relation between interlayer force and interlayer distance in the swelling of montmorillonite. Viani, Brian E.; Low, Philip F.; Roth, Charles B. (Dep. Agron., Purdue Univ., West Lafayette, IN 47907, USA). J. Colloid Interface Sci., 96(1), 229-44 (English) 1983. CODEN: JCISA5. ISSN: 0021-9797. DOCUMENT TYPE: Journal CA Section: 53 (Mineralogical and Geological Chemistry) Oriented gels of Na-montmorillonites having values of surface charge d. (s) of ~28,000-56,000 esu/cm2 were confined in a closed chamber between a N2-gas piston and a porous ceramic plate in contact with a soln. of 10-4 N NaCl. Successively higher pressures up to 6.9 bars were applied by the N2-gas piston while the NaCl soln. was maintained at atm. pressure. After equilibration at each applied pressure, the c axis spacing of the silicate layers was measured by x-ray diffraction. Subsequently, the thickness of a silicate layer was subtracted from this spacing to obtain the corresponding interlayer sepn., l. Since at equil. the swelling pressure (P) is equal to the applied pressure, P could be detd. as a function of l, for each montmorillonite. P Is an exponential function of 1/l. Also, at any P, the value of l is independent of s. Neither of these findings is consistent with the double layer (i.e., osmotic) theory of swelling.In this experiment, several chemicals are used like 1318-93-0 Therefore, an addnl. force, which is the dominant force at the obsd. values of l, must be responsible for swelling. In view of an empirical relation that exists between P and any property of the water in the swollen system, this addnl. force is postulated to result from in-depth perturbation of the water by the surfaces of the montmorillonite [1318-93-0] layers. .

Water sorption on calcium-saturated clays: II

Water sorption on calcium-saturated clays: II. Internal and external surfaces of montmorillonite. Ormerod, E. C.; Newman, A. C. D. (Rothamsted Exp. Stn., Harpenden/Herts. AL5 2JQ, UK). Clay Miner., 18(3), 289-99 (English) 1983. CODEN: CLMIAF. ISSN: 0009-8558. DOCUMENT TYPE: Journal CA Section: 53 (Mineralogical and Geological Chemistry) Water-sorption isotherms and interlamellar spacings were measured for Ca-montmorillonite (from Redhill, UK) over the relative pressure range 1 > p/p0 > 0. By taking account of the change in interlamellar vol. with relative pressure, it is shown that internal and external surfaces can be calcd. by a modified t-plot anal. The results also show that sorption on the external surfaces of the montmorillonite [1318-93-0] is quant. similar to that on ref. oxide surfaces.In this experiment, several chemicals are used like 7732-18-5 and 1318-93-0 Desorption-sorption hysteresis occurred and was apparently caused by an ageing process in which the interlamellar vol. increased at the expense of the external surfaces. .