Crystalline Swelling Process of Mg-Exchanged Montmorillonite: Effect of External Environmental Solicitation

Table 1

Qualitative XRD investigation versus % RH in the case of the first hydration-dehydration cycle.

	% RH	d001	FWHM	ξ	Character
Hydration process	40	15.52	1.03	0.77	I
	50	15.96	1.09	0.67	I
	60	16.46	0.94	0.47	I
	70	16.60	0.82	0.34	H
	80	16.74	0.68	0.21	H
Dehydration process	70	16.40	0.70	0.13	H
	60	16.07	0.78	0.18	H
	50	15.70	0.89	0.15	H
	40	15.32	0.91	0.26	H
	30	14.98	0.95	0.41	I
	20	14.42	1.34	0.48	I
	10	12.90	1.50	0.72	I
Rehydration process	20	13.55	1.54	0.53	I
	30	13.80	1.50	0.83	I
	40	15.20	1.48	0.20	I

Note: position d₀₀₁ and FWHM of the 001 reflection are given in angstroms and in °2θ CuKα, respectively. The ξ parameter which accounts for the departure from rationality of the 001 reflection series is calculated as the standard deviation of the l × d₀₀₁ values calculated for the Xi measurable reflections (Xi = 3 in this case) over the 2–40°2θ CuKα angular range. (I) and (H) indicate Interstratified hydration character and Homogeneous hydration character.