mgcl2/c2h5oh adducts with constant relative ratio of 1/3 were prepared and kept at 120oc for different lengths of times of 5, 10, 20, 30, 50, 90,120 and 220 h. then the samples were quenched and analyzed by xrd and bet. no meaningful changes were observed in the specific surface area of the samples, while xrd spectra showed 3 peaks at 2θ<15o for samples kept at 120oc for 5 h. these 3 peaks were...

A series of 1-alkyl-3-methylimidazolium hexafluorocomplex salts (C(x)MImAF(6), x = 14, 16 and 18, A = P, As, Sb, Nb and Ta) have been characterized by thermal analysis, X-ray diffraction and polarized optical microscopy. A liquid crystalline mesophase is observed for all the C(16)MIm and C(18)MIm salts. The C(14)MIm(+) cation gives a liquid crystalline mesophase only with PF(6)(-). The temperat...

single-walled carbon nanotubes (swcnt) and multi-walled carbon nanotubes(mwcnt) were melt-blended with polyvinylidene fluoride (pvdf).ft-ir technique revealed that swcnt has insignificant effect on the crystalline structure of pvdf and at 3wt% modification only 14% beta crystal isformed. this observation was accounted for by the chair structure of swcnt. in mwcnt nancomposites it was found that...

Raman and infrared spectra of Boc-(L-Val-D-Val),-OMe [(LD-Val),], with n = 4, 6 and 8, were obtained in crystalline and solution states. Based on predictions from normal-mode calculations of a number of relevant singleand double-stranded p-helix conformations, structures were assigned for the three oligopeptides under the abovementioned conditions. In the crystalline state, all three oligopepti...

INTRODUCXION Gas hydrates are crystalline molecular complexes formed from mixtures of water and suitably sized gas molecules. Based on hydrogen bonding, water molecules form unstable lattice structures with several interstitial cavities. The gas molecules can occupy the lattice cavities and, when a minimum number of cavities are occupied, the crystalline structure becomes stable and solid gas h...