Effect of graphene doping of holographic polymer‐dispersed liquid crystals

Abstract

Doping a polymer matrix with a minute amount of graphene (0.05–0.25%) had significant effects on the grating formation kinetics and electro‐optical performance of a holographic polymer‐dispersed liquid crystal. Low graphene contents (≤0.1%) reduced the viscosity and induced rapid diffusion, curing, grating formation, and high diffraction efficiency with a diffraction overshoot of 0.05%. Conversely, high graphene contents increased the compound viscosity, and the entire process proceeded slowly. Graphene increased the polymer conductivity and local electric field, reduced the operating voltage from 65 to 25–50 V, and increased the contrast ratio from 7 to 8–23 with a concomitant decrease in rise time. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Light‐directed mesoscale phase separation via holographic polymerization

“…An one way to reduce the inherently high switching voltage of HPDLCs is incorporation of conductive polymer, or small, transparent conductive particles . HPDLCs were doped with 0–0.25 w/w % graphene; loadings this low slightly increased the phase separation of LC with the photopolymer, but overall did not significantly affect the morphology . The DE was increased from 46% to a maximum of 70% with 0.1 w/w % graphene, and the switching voltage was reduced from greater than 65–25 V, shown in Figure .…”

“…DE plotted with respect to applied voltage for HPDLCs loaded with 0.0–0.25 w/w % graphene, G00 and G25 denoted as 0.0 and 0.25 w/w % respectively …”

Effect of macro-RAFT agent on the morphology of polymer dispersed liquid crystals

“…[14] Kim et al investigated the effects of doping a polymer matrix with graphene on the diffusion and grating formation rates, and confirmed that the graphene can broaden the width of LC layer. [15] In our previous studies, macro-(RAFT) reversible additional fragmental chain transfer agents prepared by RAFT polymerisation were used to fabricate PDLCs in photo PIPS process. Our previous papers focused on investigating the influence of the structure of macro-RAFT agents on EO properties, and obtained the PDLCs with low switching voltage and weak memory effect.…”

Graphene Oxide Modified with Mesogenic Groups and Its Effect in Broad‐Band Reflectors

“…[15][16][17][18] Among currently available nanomaterials, graphene, classified as at wo-dimensional (2D) carbon allotrope, has attracted much attention forp otentiala pplications in electronic devices and nanocomposites since its successful isolation in 2004. [19] As the interest in LC suspensions grows readily in current nanoscience, researchers have recently investigated optical manipulation in an LC/graphene nanostructure [20] as well as applications of graphene in cholesteric [21] and polymer-dispersed [22] LCs.…”