Authors: Wincure, Benjamin; Rey, Alejandro

Source: Liquid Crystals, Volume 34, Number 12, December 2007 , pp. 1397-1413(17)

Publisher: Taylor and Francis Ltd

Abstract:

This paper presents a computational study of defect nucleation associated with the kinetics of the isotropic-to-nematic phase ordering transition over heterogeneous substrates, as it occurs in new liquid crystal biosensor devices, based on the Landau-de Gennes model for rod-like thermotropic nematic liquid crystals. Two regimes are identified due to interfacial tension inequalities: (i) nematic surface film nucleation and growth normal to the heterogeneous substrate, and (ii) nematic surface droplet nucleation and growth. The former, known as wetting regime, leads to interfacial defect shedding at the moving nematic-isotropic interface. The latter droplet regime, involves a moving contact line, and exhibits two texturing mechanisms that also lead to interfacial defect shedding: (a) small and large contact angles of drops spreading over a heterogeneous substrate, and (b) small drops with large curvature growing over homogeneous patches of the substrate. The numerical results are consistent with qualitative defect nucleation models based on the kinematics of the isotropic-nematic interface and the substrate-nematic-isotropic contact line. The results extend current understanding of phase ordering over heterogeneous substrates by elucidating generic defect nucleation processes at moving interfaces and moving contact lines.

Document Type: Research article

DOI: http://dx.doi.org/10.1080/02678290701614657

Affiliations: 1: Department of Chemical Engineering and McGill Institute of Advanced Materials, McGill University, Montreal, Quebec, Canada H3A 2B2

Publication date: 2007-12-01

More about this publication?

• Editorial Board
• Information for Authors
• Subscribe to this Title
• ingentaconnect is not responsible for the content or availability of external websites

Related content

• In this: publication
• By this: publisher
• In this Subject: Chemistry (General)
• By this author: Wincure, Benjamin ;  Rey, Alejandro

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers