Biomedical subjects

Prabir K Mukherjee

Publications and source records attributed to Prabir K Mukherjee.

4 recordsLinked to original sources

PubMed2007

Phenomenological theory of the nematic to lamellar phase transition in lyotropic liquid crystals.

A phenomenological theory is presented to describe the nematic to lamellar phase transition in lyotropic liquid crystals. The problem of the first or second order transition is explored by means of the variation of the surfactant concentration. The possibility of the tricritical point at the nematic to lamellar phase transition is discussed in a phenomenological way. The influence of the electrolyte on this transition is also discussed by varying the coupling between the electrolyte concentration variables and the order parameters. The theoretical prediction is found to be in good qualitative agreement with experimental results.

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PubMed2005

Anomalous heat capacity above the isotropic-chiral-smectic-C phase transition.

A phenomenological model is developed to describe the isotropic-chiral-smectic-C phase transition. The anomalous part of the heat capacity of the chiral-smectic-C liquid crystals above the isotropic-chiral-smectic-C phase transition is calculated using Landau's fluctuation theory. The temperature dependence of the heat capacity above the transition point is calculated first for the Gaussian model and then taking the cubic and the quartic terms as a perturbation. The theoretical results are found to be in good agreement with experiment.

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PubMed2004

Landau model of the direct isotropic to smectic-C*A phase transition in antiferroelectric liquid crystals.

An orientational order parameter is proposed for the isotropic to smectic C*A phase transition in antiferroelectric liquid crystals. A phenomenological theory is developed to describe the direct isotropic to smectic-C*A phase transition on the basis of a free energy expansion. The free energy is written in terms of the coupled order parameters including the antipolar correlations. We present a detailed analysis of the different phases that can occur and analyze the question: under which conditions a direct isotropic to smectic-C*A phase transition is possible when compared to other phase transitions? The theoretical results are compared with experimental results.

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PubMed2002

Pressure effect on the smectic-A-isotropic phase transition.

We examine the effect of pressure on the smectic-A-isotropic phase transition within the Landau phenomenological theory. The influence of pressure on the smectic-A-isotropic phase transition is discussed by varying the coupling between the orientational and the translational order parameter. The transition is found to be of first order even at elevated pressure. The pressure dependence nonlinear dielectric effect in the isotropic phase of the smectic-A-isotropic transition is calculated. The theoretical results are in good qualitative agreement with available experimental results.

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