Transmission holographic polymer dispersed liquid crystals based on a siloxane polymer.
The low surface energy and the great immiscibility of poly (dimethylsiloxane) (PDMS) with liquid crystals (LCs) are used in the fabrication of holographic polymer dispersed liquid crystals (HPDLCs). By adding increasing amounts of PDMS, the extent of the phase separation between the polymer and the LC, the LC channel width, and-eventually-also the diffraction efficiency of the film can be increased, while keeping the droplet size essentially the same. In addition, the presence of PDMS causes a decrease in the switching voltage and an increase in the response time. At an optimum content of PDMS (PUA40), a minimum switching voltage of 4 V microm(-1), a rise time of 0.20 ms, and a decay of 14.75 ms were obtained. Regarding the effect of the LC content, an overshoot of the diffraction efficiency was observed when the amount of LC exceeded 35 %, which can be attributed to droplet coalescence.
Woo
Ju Yeon
JY
Dept. of Polymer Science and Engineering, Pusan National University, Busan 609-735, Korea.
Kim
Eun Hee
EH
Kim
Byung Kyu
BK
D002627:Chemistry, Physical / Q000379:methods*; D004058:Diffusion; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D050866:Liquid Crystals / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D055095:Optics and Photonics; D011108:Polymers / Q000737:chemistry*; D012828:Silicones / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors
D004129:Dimethylpolysiloxanes; D011108:Polymers; D012828:Silicones; D012833:Siloxanes; C013830:baysilon