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arXiv · 1507.01737

Electric field induced birefringence in non-aqueous dispersions of mineral nanorods

Alexis de la Cotte·Pascal Merzeau·Jong Wook Kim·Khalid Lahlil·Jean-Pierre Boilot·Thierry Gacoin·Eric Grelet
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Abstract

Lanthanum phosphate (LaPO4) nanorods dispersed in the non-aqueous solvent of ethylene glycol form a system exhibiting large intrinsic birefringence, high colloidal stability and the ability to self-organize into liquid crystalline phases. In order to probe the electro-optical response of these rod dispersions we study here the electric-field-induced birefringence, also called Kerr effect, for a concentrated isotropic liquid state with an in-plane a.c. sinusoidal electric field, in conditions of directly applied (electrodes in contact with the sample) or externally applied (electrodes outside the sample cell) fields. Performing an analysis of the electric polarizability of our rod-like particles in the framework of Maxwell-Wagner-OKonski theory, we account quantitatively for the coupling between the induced steady-state birefringence and the electric field as a function of the voltage frequency for both sample geometries. The switching time of this non-aqueous transparent system has been measured, and combined with its high Kerr coefficients and its features of optically isotropic offstate and athermal phase behavior, this represents a promising proof-of-concept for the integration of anisotropic nanoparticle suspensions into a new generation of electro-optical devices.

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Alexis de la Cotte, Pascal Merzeau, Jong Wook Kim, Khalid Lahlil, Jean-Pierre Boilot, Thierry Gacoin, Eric Grelet. 2015-07-07. Electric field induced birefringence in non-aqueous dispersions of mineral nanorods. https://arxiv.org/abs/1507.01737

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