Open AccessOptimization of particle size for high birefringence and fast switching time in electro-optical switching of graphene oxide dispersions
Author(s) -
Rana Tariq Mehmood Ahmad,
SeungHo Hong,
Tong Shen
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.004435
Subject(s) - materials science , graphene , birefringence , oxide , particle size , anisotropy , sensitivity (control systems) , optics , isotropy , polarizability , optoelectronics , nanotechnology , electronic engineering , physics , chemistry , engineering , molecule , metallurgy , quantum mechanics
In order to use graphene oxide (GO) dispersions for electro-optical applications, both a high GO concentration and a high electrical sensitivity are essential; however, these have not been achieved to date. Here, we report that by optimizing the mean size of GO particles to approximately 0.5 μm, one can obtain a high GO concentration of up to 2 wt% and high electrical sensitivity simultaneously. By reducing the mean GO-particle size, the interparticle interaction and the rotational viscosity can be significantly reduced, and a high-concentration isotropic phase can be obtained. As a result, the maximum birefringence increases and the dynamic response becomes faster. However, further decrease of the mean size below 0.1 μm causes a decrease in the anisotropy of electrical polarizability, resulting in the reduction of the electrical sensitivity of GO dispersions.