Polymer-dispersed liquid crystals (PDLCs), composed of micro-sized liquid crystal domains embedded in a continuous polymer matrix, are an important class of materials that hold promise for many opto-electronic applications. In this review, based on an analysis of research publications appearing between 2006 and 2012, preparation of conventional PDLCs and nanoparticles-doped PDLCs, their properties, and their application for opto-electronic devices are described.

Polymer-Dispersed Liquid Crystals: Progress in Preparation, Investigation, and Application

Flexible, ferroelectric nanoparticle doped polymer dispersed liquid crystal devices for lower switching voltage and nanoenergy generation

Optically isotropic liquid crystal (OILC) mixtures utilising polymerisation-induced phase separation in mixtures of prepolymers and liquid crystals (LCs) have been made and their overall electro-optic performances have been tested by applying an in-plane electric field for flexible display application. Excellent transparent films with a LC to prepolymer weight ratio of 42:58 are achieved and confirmed by SEM images. The average LC droplet size inside the polymer matrix is 215 nm. Consequently, an in-plane driven LC device with a crossed polariser shows a very high contrast ratio over 1000 comparable to the conventional nematic in-plane switching cell, wide viewing angle, a low threshold voltage of 8.2 V, hysteresis free and fast response time. The proposed LC device is free from an alignment layer and the rubbing process and its dark state is not disturbed by mechanical pressure, which can open its application to flexible liquid crystal displays.

Optically isotropic liquid crystal mixtures and their application to high-performance liquid crystal devices

Effect of ferroelectric nanoparticles in the alignment layer of twisted nematic liquid crystal display

A liquid crystal device with optically isotropic liquid crystal (OILC) phase induced from polymerization-induced phase separation exhibit a fast response time and a proper dark state. Its electro-optic performances are highly influenced by a kind of materials and processing conditions. Here, the effect of materials and phase-separation on the electro-optic performance of OILC device has been investigated by utilizing the acrylate and the thiol-ene monomer mixtures. The optically isotropic phase was analyzed with scattering theory, and it was revealed that a novel polymer network structure of acrylate mixture is free of scattering and yields a higher on-state transmittance, enhanced by ~50%. By tuning the monomer ratio and UV intensity, an excellent transparent film was obtained and, in addition, the response time was improved by ~40%. The excellent black state and its flexibility can be applied to flexible liquid crystal photonic and display devices.

Fast switchable field-induced optical birefringence in highly transparent polymer-liquid crystal composite

Obesity is hallmarked by endoplasmic reticulum (ER) stress, chronic inflammation and metabolic dysfunctions. The control of obesity is the key to prevent the onset of non-alcoholic fatty liver disease, diabetes,...

Biodegradable celastrol-loaded albumin nanoparticles ameliorate inflammation and lipid accumulation in diet-induced obese mice

In this work we analyse the fabrication of Polymer Dispersed Liquid Crystals (PDLCs) using SU8-2002-2007 photoresist and 5CB and E7 Liquid Crystals. Also we report the nonlinear optical behaviour for these materials and for Polymer Dispersed Liquid Crystals with a Twisted Cell (T-PDLC). We found that depending of several parameters, the droplets size varies from nano to micro dimensions. We report for first time, to our best knowledge, the synthesis of a SU8 Polymer Dispersed Liquid Crystal (PDLC) by using the polymer SU8 photoresist and liquid crystals (LC) and also the nonlinear behaviour of T-PDLC. We have characterized the droplets formation from nano to micron size depending of the different variables in the synthesis. We have used this PDLC in microfabrication as planar waveguides of different thickness over Si wafers. Our results also show that PDLCs present low NL optical Kerr coefficient (n2 about 10-9cm2/W) and that it is three orders of magnitude larger in T-PDLC. Nevertheless, the fabrication processes of T-PDLCs make impossible their use in microfabrication. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Q. Song

Papers

Biodegradable celastrol-loaded albumin nanoparticles ameliorate inflammation and lipid accumulation in diet-induced obese mice

Nano‐droplet formation in polymer dispersed liquid crystals

Celastrol-Lac-BSA nanoparticles attenuate hepatic steatosis in non-alcoholic fatty liver disease.

Targeting unfolded protein response using albumin-encapsulated nanoparticles attenuates temozolomide resistance in glioblastoma