Photoisomerization-Controlled Phase Segregation in a Submicron Confined Azonematic Liquid Crystal

B. Zupančič, S. Diez-Berart, D. Finotello, O. D. Lavrentovich, and B. Zalar

Phys. Rev. Lett. 108, 257801 – Published 18 June 2012

Abstract

Deuteron nuclear magnetic resonance is used to study the phase segregation behavior of photoisomerizable liquid crystal diheptylazobenzene (7AB) confined into cylindrical pores of Anopore membranes. It is demonstrated that the concentration of both components in a binary trans-7AB and cis-7AB mixture can be controlled dynamically using UV-illumination stimulated trans-to-cis photoisomerization and thermally induced cis-to-trans backisomerization. The so far elusive temperature-concentration phase diagram of such system is determined by comparative analysis of the behavior in bulk, thin-planar, and Anopore-confining geometry.

Received 29 March 2012

DOI:https://doi.org/10.1103/PhysRevLett.108.257801

Authors & Affiliations

B. Zupančič^1,2,3, S. Diez-Berart⁴, D. Finotello⁵, O. D. Lavrentovich⁶, and B. Zalar^1,2,3

¹Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
²Centre of Excellence NAMASTE, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
³Centre of Excellence EN-FIST, Dunajska cesta 156, SI-1000 Ljubljana, Slovenia
⁴Grup de les Propietats Físiques dels Materials (GRPFM), Departament de Física i Enginyeria Nuclear, E.T.S.E.I.B., Universitat Politècnica de Catalunya, Barcelona, Spain
⁵National Science Foundation, 4201 Wilson Blvd., Arlington, Virginia 22230, USA
⁶Liquid Crystal Institute, Kent State University, Kent, Ohio 44242-0001, USA