ISSN:
1435-1536
Keywords:
Thalliumsoaps
;
X-raydiffraction
;
latticeparameters
;
unitcell
;
phasebehavior
;
polymorphism
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The results of X-ray diffraction patterns of homologous thallium soaps TlC n (n-8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 20 and 22) in dependence on the temperature showed that the structures of the phases below the temperature range of the liquid-crystalline neat phase (so called phase C1, phase C2, phase I, phase II) are crystalline-like, not liquid-crystalline. As function of the chain length of the fatty acid group, we found the following phase sequences to be a function of temperature: TlC8: phase I↔neat phase: TlC9−Tl14: phase C2↔phase II↔phase I↔neat phase; TlC15, TlC16: phase C1↔phase II↔phase I↔neat phase; TlC17−TlC22: phase C1↔phase II↔neat phase. From the X-ray patterns of the thallium soaps were calculated the lattice parameters and the unit cells of these homologues at various temperatures. The comparison between the lattice parameters of the homologues showed, surprisingly, that these parameters were independent of chain length and temperature. This X-ray data are the basis for the following development of structure models of the phase C1, phase C2, phase I, and phase II, including the neat phase (see Part 2).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00655479
Permalink
