ANALYSIS OF NACRITE INTERCALATED WITH DIM ETHYLSULFOXIDE AND N-METHYLACETAMIDE

Nacrite was intercalated with two polar organic compounds: Dimethylsul phoxide (DMSO) and n-methylacetamide (NMA), which have similar dipolar moments (4 debyes) but different dielectric constants (49 for the DMS O and 179 for the NMA). The rate of the intercalation has been measure d and found to increase in order NMA>DMSO. The interlamellar homogeneo us nacrite complexes have been studied by XRD, IR and DTA. The IR nacr ite-DMSO spectrum shows that interaction between the nacrite layer and DMSO is similar to that obtained in the kaolinite-DMSO complexes. The IR spectrum of the nacrite-NMA complex shows three absorption bands a t 3500, 3543 and 3589 cm(-1). The v(N-H) frequencies of the NMA in the complex are intermediate between those of dilute non-polar solution a nd the liquid. This could arise from a degree of association between N -H and O-Si. By XRD, 13 basal reflections were obtained for each compl ex. The direct method involving a monodimensional electron density pro jection on the z-axis for each homogeneous complex enabled us to find the amount of organic compound per unit-cell (one molecule per Si2Al2O 5(OH)(4)) and their orientation in the interlamellar space. The DTA sh owed that the Nac.DMSO complex is more stable than the Nac.NMA complex .