Theoretical Study of Nematic to Isotropic Transition in Porous Media

• Authors: A. Govind , Kumarii Banerjee
• Languages of publication: EN

Abstracts

EN

Experimental observations show that the N-I transition temperature (T_{NI}) for liquid crystals embedded in solid porous materials is lower compared to that of the bulk liquid crystals and T_{NI} is reduced linearly with the inverse pore diameter. To explain this, various theoretical studies have been proposed. We propose to use the mean field approach. We modify the Maier-Saupe mean field theory to include the disordering effects of porosity as a disordering surface potential. A molecule near the surface is assumed to feel the mean field potential (the Maier-Saupe type) and also the surface induced potential. We calculate the values of the nematic order parameter and hence find the T_{NI} for different pore diameters. The weighted average of the order parameter is calculated considering the cylindrical symmetry of the pores. Our calculations on the variation of T_{NI} with pore diameter agree with experimental data. Also, the calculated values of specific heat peak decrease with decrease in pore radius, in agreement with experimental trends.

Keywords

EN

61.30.-v; 61.30.Cz; 64.70.M-; 61.30.Pq

Discipline

• 61.30.Pq: Microconfined liquid crystals: droplets, cylinders, randomly confined liquid crystals, polymer dispersed liquid crystals, and porous systems
• 61.30.Cz: Molecular and microscopic models and theories of liquid crystal structure
• 61.30.-v: Liquid crystals(for phase transitions in liquid crystals, see 64.70.M-; for liquid crystals as dielectric materials, see 77.84.Nh; for liquid crystals as optical materials, see 42.70.Df; for liquid crystal devices, see 42.79.Kr)
• 64.70.M-: Transitions in liquid crystals

• Journal: Acta Physica Polonica A
• Year: 2016
• Volume: 130
• Issue: 3
• Pages: 748-750

Dates

published

2016-09

received

2015-12-21

(unknown)

2016-06-10

Contributors

author

A. Govind

• Department of Physics, Vijaya College, R.V Road, Basavanagudi, Bangalore, 560 004, India

author

Kumarii Banerjee

• Jain University, Bangalore, India

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Identifiers

DOI

10.12693/APhysPolA.130.748