Effects of the structures of polymerizable monomers on the electro‐optical properties of UV cured polymer dispersed liquid crystal films

Abstract

Polymer dispersed liquid crystal (PDLC) films were prepared by photopolymerization of liquid crystal (LC)/polymerizable monomers/photoinitiator composites. The effects of the structures of the polymerizable monomers on the electro-optical properties of PDLC films were investigated. It was found that the length of the molecular chain and the rigidity and flexibility of molecules influenced the structure of the polymer network in the PDLC films somewhat, and then affected the electro-optical properties of the composites accordingly.

Comparative studies of polymer‐dispersed liquid crystal films via a thiol‐ene click reaction

“…The PIPS method is versatile and usually applied for fabricating PDLC films because of its stability, fast curing speed, uniformity, and controllability under photoinitiated polymerization conditions . Applied PDLC devices in the present typically have high driving voltages (greater than 50 V), long response times (greater than 50 ms), and low contrast ratios (less than 100), which can be achieved by varying the morphology of the PDLCs, via changing the LCs and the monomers employed such as the polymerizable group and the polymerization conditions …”

Effect of Curing Process on the Dynamic Response of Polymer Dispersed Liquid Crystal Films

“…[7][8][9][10][11][12][13] Deshmukh et al investigated the effects of temperature and composition on the optical and electro-optical properties of a linear polymer/LC system. [8] The influence of the nature of monomers, crosslinking agents, and additives on sample morphology and electro-optical performances has been studied by White et al, [9] Li et al, [10] Kashima et al, [11] He et al, [12] and Wang et al. [13] Macromol.…”

New Polymer Networks for PDLC Films Application

“…Smaller domain size can be achieved by higher viscosity of the systems and poor diffusion of free radicals of the polymerisable monomers during polymerisation and hence the reduced coalescence of LC domains. Therefore, small LC domains can be obtained 8,20 .…”

“…The polymer matrix acquires a particular morphology with liquid crystal dispersed in its clusters 1 . The polymerisation conditions 8 , the chemical…”

“…The electrooptical properties of PDLC films prepared by the polymerisation induced phase separation (PIPS) method depend on a numbers of factors such as the type of liquid crystal, molecular structure of polymerisable monomers and polymeric conditions. These factors could seriously affect the microstructure of the polymer matrix, the size and the shapes of the LC domains and molecular interactions between the LC molecules and the polymer matrix (anchoring effect) 8,[18][19][20] . In general and in a simple way, in a nematic liquid crystal there is a relationship between the size and the shape of LC domains and the anchoring effect.…”