The development of structural peculiarities of supercooled MBBA in Raman spectra contours

Pogorelov, V.; Estrela-llopis, Iryna

doi:10.1016/0022-2860(95)08640-h

Cited by 7 publications

(2 citation statements)

References 5 publications

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“…When new band vbl=1597 cm-' [3] attains the integral intensity maximum in N-phase, we observe[31 the single symmetrical broadened band v b displaced to high-frequency region (the quantity of conformers with v=l168 crn-' is practically equal to the quantity of conformers with v=l160 cm-I).…”

Section: Shade Of Raman Bands and Dvnamics Of Structural Transformationsmentioning

confidence: 97%

Spectroscopy of Phase Transitions in Liquid Crystals

Pogorelov

Pinkevich

Estrela-llopis

et al. 1998

Molecular Crystals and Liquid Crystals Science and Technology.

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The results of study of structural genesis of the nonoriented nematic MBBA at different temperature pre-history are reported. The temperature dependent transformations of the vibrational Raman spectra and their connection with the change of MBBA structure were investigated in the spectral region 1100-1600 cm-' and in the temperature interval 163-333 K. The method to be used allows to prognosticate the structural evolution of MBBA and to identify its phase states. In particular it is found that the several coexisting fractions of different conformers may be obtained in the temperature region lower the glass transition temperature in dependence on the sample cooling rate.

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Section: Shade Of Raman Bands and Dvnamics Of Structural Transformationsmentioning

confidence: 97%

Spectroscopy of Phase Transitions in Liquid Crystals

Pogorelov

Pinkevich

Estrela-llopis

et al. 1998

Molecular Crystals and Liquid Crystals Science and Technology.

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“…The transition of bulk MBBA from the metastable crystalline (C ) phase to the nematic (N) phase (T C N ) occurs at 294 K, from the stable crystalline phase (C) to the nematic phase (T CN ) at 295.3 K, and from the nematic phase to the isotropic liquid (I) phase (T NI ) at 317 K [6]. In addition, MBBA forms multiple metastable crystalline phases and the glass transition of the supercooled nematic phase is observed at T g = 205 K. The appearance of the metastable crystalline phase depends on the thermal history of the cooling process, as investigated by NMR, DSC, X-ray, Raman, and dielectric experiments [7][8][9][10][11]. Mansare et al [12] used controlled-pore glasses with different pore sizes to investigate the effects of confined space on phase transitions of liquid crystals.…”

Section: Introductionmentioning

confidence: 99%

Phase Transitions of N-(4-methoxybenzylidene)-4-butylaniline (MBBA) Confined within Mesoporous Silica

et al. 2020

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We have used differential scanning calorimetry (DSC) to investigate the phase transition of a liquid crystal, N-(4-methoxybenzylidene)-4-butylaniline (MBBA), confined within porous silica materials with one- and three-dimensional pore architectures. Each phase-transition temperature of the confined MBBA linearly decreased with the inverse pore size compared with that of bulk MBBA. However, the degree of temperature shift varied owing to differences in the pore architectures. In addition, when MBBA was confined within one-dimensional pores, the thermal anomaly associated with the phase transition from the nematic phase to the isotropic liquid phase was not observed in the DSC measurements.

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