The Effect of UV Intensities and Curing Time on Polymer Dispersed Liquid Crystal (PDLC) Display: A Detailed Analysis Study

다국어 초록 (Multilingual Abstract)

In current study polymer dispersed liquid crystal (PDLC) films whosecomposition based on nematic liquid crystal (LC) E7 and prepolymericNOA65 were formed via the photo induced phaseseparation method, in a wide intensity range of the UV light (I = 0.33-1.8 mW/cm2) and curing duration (t = 120-600 sec). The PDLCcharacteristics were monitored by surface morphology, electro opticalstudies, as well as by phase separation process through measuring theFTIR absorption of the composite layers. Increase of curing lightintensity accelerates the phase separation and drastically influencesthe final morphology of LC droplets inside PDLCs. Likewise bywidening the curing duration the enhancement in phase separationwas observed. Increase of light intensity from 0.89 mW/cm2 andduration t = 120-240 sec resulted into transition from large LCdomains of irregular shape (due to aggregation of droplets) to finemono dispersed LC droplets. This morphology caused increase inoptical scattering on zero voltage and high driving voltage. Howeverunexpectedly, this response was not directly related with the curingconditions (intensity and time). These findings extend the potentialapplications of thiol-ene based PDLCs.

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