Characterization of Some Liquid Crystals through Sound and Thermodynamic Parameters

Vasan, S.T.; Sannaningannavar, F. M.; Ayachit, N. H.; Deshpande, D. K.

doi:10.1080/154214090964591

Cited by 9 publications

(11 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results obtained here are in consistent with the inferences drawn in earlier work of the authors [1], using sound measurements. …”

Section: Resultssupporting

confidence: 95%

“…The values of specific volume obtained and reported in earlier work [1] for PAA are used for the calculation of the different parameters as defined in the later section. The values so obtained are presented in Tables 1 and 2.…”

Section: Resultsmentioning

confidence: 99%

“…Using the measured values of the density d (reported in an earlier work [1]), various physical parameters are derived with the help of their defining equations listed above, and the results are presented in Tables 1 and 2. The variation of the each of the physical parameter, can be observed from the tables.…”

Section: Resultsmentioning

confidence: 99%

“…The results of the above work is presented in this article and discussed. The results of these are also compared with the one carried with ultrasonic measurements [1].…”

Section: Introductionmentioning

confidence: 96%

See 3 more Smart Citations

Thermodynamic Functions of a Liquid Crystal through Density Measurements

Ayachit

2009

Molecular Crystals and Liquid Crystals

View full text Add to dashboard Cite

Thermodynamic functions of a material are determined using ultrasonic measurements coupled with volumetric measurements at different temperatures. It is also possible to determine some of these thermodynamic functions using only volumetric measurements. Such studies are important in the case of liquid crystal as they give insight in the structural changes arising out of transition between two phases. Apart from this, these studies are also found to give clear information regarding the nature of phase transition, pre-transitional effects, and molecular ordering. Some of the thermodynamic functions calculated are adiabatic compressibility, order parameter, Sharma's number, etc. In the present study these different parameters have been determined using only volumetric measurements in case of 4,4 -azoxy anisole at different temperatures. Variations in various parameters with respect to temperature have been discussed in the light of the results obtained. In the literature the data for these parameters are available for the above said liquid crystal calculated in conjunction with ultrasound measurements. The results obtained in the present work are compared with these results. It has been shown that the variation of the properties observed with respect to temperature can be explained on the basis of Frenkal's heterophase fluctuation theory.

show abstract

“…The results obtained here are in consistent with the inferences drawn in earlier work of the authors [1], using sound measurements. …”

Section: Resultssupporting

confidence: 95%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“…The results of the above work is presented in this article and discussed. The results of these are also compared with the one carried with ultrasonic measurements [1].…”

Section: Introductionmentioning

confidence: 96%

See 2 more Smart Citations

Thermodynamic Functions of a Liquid Crystal through Density Measurements

Ayachit

2009

Molecular Crystals and Liquid Crystals

View full text Add to dashboard Cite

show abstract

“…The various phenomena that take place near the phase transition can however be explained on the basis of Frenkel's heterophase fluctuation theory. This observation is in line wth earlier observations [24][25][26][27]. …”

Section: The Numbers In the Brackets Insupporting

confidence: 92%

Time Domain Reflectometry Studies on a Nematic Liquid Crystal

Fattepur¹,

Ayachit

Mehrotra

2009

Molecular Crystals and Liquid Crystals

View full text Add to dashboard Cite

The complex dielectric permittivity spectra of p-pentyl phenyl-p-propylbenzoate (PPPB) ðK À! 13 C N À! 17 C IÞ, of a nematic liquid crystal are obtained using Time DomainReflectometry (TDR) method over a frequency range 10 MHz-10 GHz at various temperatures covering both nematic and isotropic phases. The relaxation behavior at different temperatures was studied through cole-cole arc. The dielectric behavior in nematic (N) phase could be described by the Cole-Davidson model, while isotropic (I) phase is found to obey to a large extent Debye model. Two relaxation times, s 1 and s 2 , are obtained for N phase which are the characteristic of Cole-Davidson model. s 1 and s 2 are interpreted as corresponding to different degrees of freedom in different direction in liquid crystalline state. The fact that s 1 and s 2 obtained for the I phase are almost equal favors Debye model. The results are presented over a temperature range, and these results are discussed to understand the phase transition involved. The work included in this article is useful as it provides information about the macroscopic structure of the liquid crystals in general and PPPB in particular. The N phase is the least ordered of liquid crystalline phases, and hence the studies even on an unaligned samples give information that is very close to aligned ones as far as those properties which are due to overall effects like dielectric behavior.

show abstract