Intercalated structure

The nano-scale structures in polymer layered-silicate nano-composites can be thoroughly characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD is used to identify intercalated structures. XRD allows quantification of changes in layer spacing and the most commonly used to probe the nano-composite structure and... 

From calculations of the preferred conformation of the ephedrine and pseudo ephedrine molecules the topography of the adrenergic receptor as a flat surface has been deduced (26). This view, however, does not explain the decisive effect of the additional methyl group its relative position should not influence the interaction with the proposed receptor to a large extent (Fig. 7a). However, as the differences in activities are especially high for the ephedrine and pseudo ephedrine isomers, we believe that the receptor must have an intercalated structure similar as projected for the "binding sites" of the silicones (Fig. 7b). ... 

Cp6 together with the Intercalator acridine orange solved at atoaiic resolution (36). It can be seen tha the 3 end of the double helical RNA fragment has adopted the C2 endo conformation while the S end maintains the normal C3 endo conformation. A large number of intercalator structures of this type have been solved and they have been summaried elsewhere. Sobell and his colleages pointed out that the Intercalation is associated with a modification of the pucker of the ribonucleotide chain on the 3 end of the intercalator (37-38). Although intercalation is generally associated with the conformations similar to those seen in Fig. 10. a number of alternative conformations have been found with more complex Intercalators. 

The morphology of rubber-based nanocomposites also seems to change in the presence of compounding ingredients [89, 90]. HNBR, when melt-compounded with organo-modified sodium montmorillonite clays (o-MMTs) prior to sulfur curing, resulted in the formation of nanocomposites with exfoliated or intercalated structures. In stark contrast, under similar conditions HNBR compounded with unmodified sodium montmorillonite clays (NA) formed microcomposites [90]. This was traced to its reactivity with the sulfur in the presence of amine-type organomodifiers. 

The nature of the surface promoter species has been debated for many years. As MoS2 crystals exist as layered structures, two models evolved. One proposed that the promoter was intercalated deep within the bulk of the MoS2 layers (51) and another proposed that bulk intercalation was not thermodynamically stable and a surface-intercalated structure was more likely (52) (see Fig. 16d). Both proposals related the promotion to crystal surface reconstruction and solid-state chemistry and are valid only for multilayered structures. 

In many cases the important property will actually be the permeability, which is the product of the diffusion coefficient and the solubility of the dopant in the polymer. The solubility is determined by the degree of interaction between the diffusant and the polymer. The picture is further complicated, since reactions may take place so that several different species are diffusing. The reaction of a gaseous dopant with a conducting polymer is a complicated diffusion and reaction process. We must consider the solubility and diffusion of the molecular gas, the charge-transfer reaction to dope the polymer, the diffusion of the resulting ions in the doped (intercalated) structure and any reaction between the dopant ions and the polymer which may lead to covalent bonding. 

Figure 2 shows the initial equilibrated intercalated state. The DNA sequence is d(GCGCACGTGCGC)2- The intercalated structure s geometry is that of the B-DNA except for the 5th to 7th base pairs (A5 to G7), which stay close to the crystal structure used for the starting conformation, with a root mean square deviation of 3.2 A for all the heavy atoms of those three basepairs. In this sequence, daunomycin is in contact with the strongest binding triplet sequence (A/T)CG [18,19]. Moreover, due to the chosen sequence of the DNA, the intercalation site is flanked by the same sequence of base-pairs in either direction, eliminating any related orientational preference of... 

It is proposed that the intercalation of kaolinite with DMSO depends on the presence of water molecules in the interlayer space of mineral [132, 140, 144]. The water molecules are in well-defined positions within the intercalation structure. The evidence of the existence of two types of intercalated water in the DMSO-intercalation complex was obtained [132]. 

Intercalation compounds involving layered double-hydroxides (LDHs), illustrated by the structure shown in Figure 19 (Park et al., 2002), were synthesized to facilitate the measurement of the uniaxial stress (i.e., along the direction perpendicular to the layers), that host layers exert on intercalated species. Below a certain thickness of -A 00 mm, the intercalated structures become more transparent to visible light, so that the information obtained by PL represents the properties of the bulk, not of the surface. Because it is sensitive to the deformation of the intercalants, the PL from samarium complexes was employed to measure the uniaxial stress, by using PL peak positions as a function of pressure (Park et al., 2002 Sapelkin et al., 2000). 

According to C-C, C-N, and N-H bond distances and manganese oxide slab thickness, angles of organic ammonium ions between the layers were calculated [34]. In contrast to the TAA-OL-1 samples, the XRD patterns of diamine intercalated OL-1 had a typical character of intercalated structures with larger interlayer distances that correlate with longer molecular distances of different amines. 

The presence of SDS in the clay matrix permits to deposit a large amount of Au nanoparticles only on the edge of the clay and in voids created by ultrasonic treatment. (Fig. 2B) The SAXS and WAXS patterns of this composite (Fig. 1C) clearly indicate the formation of an intercalated structure and an increase of the interlamellar space between the clay layers up to 1.81 nm and 6.7 nm. 

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