Powder XRD investigations on dotriacontane in mixtures: Phase strength and super lattices

Abstract

Powder XRD investigations on dotriacontane-decane and dotriacontane-decanol mixtures are made. Phase strength, phase separation and formation of superlattices are discussed. The role of tunnel-like defects is considered.

Linear C32H66 hydrocarbon in the mixed state with C10H22, C12H26, C14H30, C16H34 and C18H38: Comparison of strength of phases and role of tunnel-like defects

“…Therefore the scope of the study undertaken by the present authors is wider than the earlier one. 1 Results of powder XRD studies on C32-C16, 2 C32-C10 and C32-C10-ol, 3 and C36-C10 to C36-C18 4 were reported earlier. Powder XRD investigations were also carried out on C32-C12, C32-C14, C32-C18 and C28-C10 to C28-C18 5 systems.…”

“…Fall in the average strength of β o phase (figure 5, curves A, B) with increasing chain length of SMOLLENC molecules (and thus decreasing total L tlid ) in the binary mixture, can be seen as direct proof of the model of interaction and the role of TLIDs as proposed earlier. 3 It is also noticed that the strength of unidentified phase U p (figure 5, curves E, F) increases with chain length of SMOLLENC component of the binary mixtures (U p was recognized as due to superlattices 3 ); this aspect can be explained as follows.…”

“…Consequently, the TLID left between the two C12 molecules remain inactive in the phase promotion. 3,4 The total value of TLID in the C32-C12 combinations is thus reduced (point d, figure 6). (ii) In case of the C32-C14 combination, a small increase in the value of L tlid can be realized (point e, figure 6), if it is assumed that two C14 molecules are always separated by a minimum gap 9 of 3 to 3⋅5 Å (figure 7b) and larger gaps are not allowed.…”

“…(Related details are given elsewhere. 2,3 ) The PXRD patterns of four systems, C32-C10, C32-C12, C32-C14 and C32-C18 are illustrated in figures 1 to 4 (in the figures, the peak heights were chopped off at 1500 cps). The powder XRD patterns of C32-C16 were presented earlier.…”

“…The powder XRD patterns of C32-C16 were presented earlier. 2 In earlier studies, [2][3][4] the phase strength was evaluated by employing the line number density approach. [6][7][8] In the present study, the total peak intensity approach was employed for the evaluation of strength of the orthorhombic (β o ), monoclinic (β m ) and unidentified phase (U p ) phases.…”