Basal plane spacing

Moriguchi et al. (43) noted a correlation between the change in the basal plane spacing with H2S exposure of CdSt, and the ionic radius of sulfide, and used this as evidence for CdS monolayer formation. Measurements of high lateral conductivity in metal ion fatty acid films exposed to H2S (20,23) and of photoelectric properties (21) have also been used to invoke the concept of continuous sheets of metal sulfide forming. 

Fio. 12. STM image of ReS2 basal plane (57). Atomic spacing corresponds to actual ReS2 basal plane spacing. 

Magnesium-vermiculite also forms monolayer hydrates with basal-plane spacings of 1.163 and 1.153 nm [23]. These hydrates are distinguished by the configuration of the Mg2+ solvation complexes (outer-sphere surface complexes) in them. The hydrate with the larger basal-plane spacing contains Mg2+ in the centers of flattened tetrahedra formed by water molecules the other clay hydrate contains Mg2+ at the apex of a pyramid whose base comprises three water molecules. 

Simulation of the ESEM pattern for Cu2+-doped Mg-montmorillonite leads to a coordination number of six and a Cu2+-D distance of 0.29 nm [41]. X-ray diffraction shows that the smectite layers are about 1.04 nm apart when the ESR lineshape becomes isotropic with a single peak. This large basal-plane spacing and the ESEM data suggest a diffuse-layer Cu(H20)g+ species that tumbles sluggishly. Copper-doped Mg-hectorite whose layers are about 0.54 nm apart yields an ESR spectrum like those for beidellite and montmorillonite at low relative humidity, whereas with the layers 1.04 nm apart, the spectrum is again isotropic [39]. Figure 8 illustrates the three Cu2+ surface complexes that appear successively as a smectite... 

Figure 1.14. Basal plane spacings of N-alkylammonium complexes with a Vertisol clay fraction and the corresponding layer charge distribution. ...

Table 1.9. Relations between carbon number (Mc) and layer charge (x), and between basal plane spacing [d(OOl)] and bilayer fraction (p) for iV-alkylammonium-smectite complexes ...

Correlation between the organic matter ionically bound to the layered silicate surface and the resulting basal plane spacing of the modified filler. (Reproduced from Mittal, V., /. Thermoplast Compos. Mater., 20, 575,2007.)... 

Similarly, other surface reactions on the filler surface can also be carried out, which lead to higher basal plane spacing. In one such study, esterification reactions on the surface of... 

Osman, M. A., Ploetze, M., and Suter, U. W. 2003. Surface treatment of clay minerals-thermal stability, basal-plane spacing and surface coverage. 

The wide-angle x-ray diffraction patterns of the polypropylene nanocomposites with and without compatibilizer have been shown in Figure 10.11. The diffraction pattern of pure imidazolium-treated montmorillonite has also been plotted for comparison. The presence of basal peaks in all the composites containing different compatibilizers indicated that full exfoliation of the filler did not take place. Also, the increase in the basal plane spacing in the composites as compared to the modified filler or the composite without compatibilizer... 

Table 1.1 Basal plane spacing values of various surface-modified montmorillonites and vermiculites [8-13].

In-situ synthesis of caprolactone in the interlayers of Cr -modified fluorohec-torite was reported by Messersmith et al. [35). The microstracture development was studied by using XRD as shown in Figure 1.17. The unintecalated filler had a basal plane spacing of 12.8 A, which was increased to 14.6 A for the intercalated filler swollen with caprolactone. After the polymerization of caprolactone in and around of filler interlayers, a final basal plane spacing of 13.7 A was observed for the nanocomposite. The observed basal plane spacing correlated well with 4-A interchain distance in the crystal structure of poly(caprolactone). 

Table 8.4 details the basal plane spacing values of the filler before and after surface modification, the suspensions of modified fillers in a solvent and the epoxy... 

Table 8.4 Basal plane spacing of the fillers, their suspensions and epoxy composites [13, 14].

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