scholarly journals Determination of liquid crystal orientation in holographic polymer dispersed liquid crystals by linear and nonlinear optics

2008 ◽  
Vol 104 (7) ◽  
pp. 073115 ◽  
Author(s):  
M. Yemtsova ◽  
A. Kirilyuk ◽  
A. F. van Etteger ◽  
Th. Rasing
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Nonlinear Optics ◽  
Crystal Orientation ◽  
Polymer Dispersed Liquid Crystals ◽  
Polymer Dispersed ◽  
Linear And Nonlinear ◽  
Liquid Crystal Orientation

Side-chain liquid-crystal epoxy polymer binders for polymer-dispersed liquid crystals

1992 ◽  
Vol 25 (1) ◽  
pp. 133-137 ◽  
Author(s):  
Liang Chy Chien ◽  
C. Lin ◽  
David S. Fredley ◽  
James W. McCargar
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Epoxy Polymer ◽  
Side Chain ◽  
Polymer Binders ◽  
Polymer Dispersed Liquid Crystals ◽  
Polymer Dispersed

Experimental Study and Modeling of Nonlinear Scattering in Polymer Dispersed Liquid Crystals

1999 ◽  
Vol 597 ◽  
Author(s):  
M. Pacilli ◽  
P. Sebbah ◽  
P. Sixou ◽  
C. Vanneste ◽  
H. Guillard
Keyword(s):  
Experimental Study ◽  
Liquid Crystal ◽  
Composite Materials ◽  
Time Domain ◽  
Nonlinear Scattering ◽  
Polymer Dispersed Liquid Crystals ◽  
Polymer Dispersed ◽  
Linear And Nonlinear ◽  
The Time Domain ◽  
Nonlinear Light Scattering

AbstractWe investigate the optical limiting capabilities of composite materials consisting of nematic liquid crystal inclusions within a polymer matrix in the millisecond and CW regime. Preparation of the composite has been optimized to decrease the operation voltage. Clear evidence of light induced reorientation is observed. A numerical model is proposed to describe multiple linear and nonlinear light scattering in the time domain in this medium. Numerical simulations are compared to experiment and confirm promising limiting characteristics of such materials.

Orientation in stretched polymer-dispersed liquid crystals

1998 ◽  
Vol 76 (11) ◽  
pp. 1642-1647 ◽  
Author(s):  
Julien Brazeau ◽  
Yanick Chénard ◽  
Yue Zhao
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Molecular Orientation ◽  
Liquid Crystalline ◽  
Polymer Dispersed Liquid Crystals ◽  
Polymer Dispersed ◽  
Infrared Dichroism ◽  
Semicrystalline Matrix ◽  
Macroscopic Orientation ◽  
Strain Direction

The orientation behavior of liquid crystal molecules in stretched films of polymer-dispersed liquid crystals (PDLC) was investigated by means of infrared dichroism. The liquid crystal used is 4prime-octyl-4-biphenyl-carbonitrile (8CN); the polymer matrices are semicrystalline poly(epsilon-caprolactone) (PCL) and an amorphous miscible blend of PCL with poly(vinyl chloride) (PVC). 8CN was found to have a limit of solubility below 5 wt.% in PCL. We show that an uniaxial stretching can effectively induce a macroscopic orientation of 8CN, and that this orientation can be preserved in the films after removal of the extensional force at room temperature, where 8CN is in its liquid crystalline phase. The molecular orientation is obtained even by stretching PDLC films with 8CN in the liquid state. These results suggest that an elongated polymer cavity in stretched PDLC imposes LC director fields with respect to the long axes of the droplets, which are aligned parallel to the strain direction. The experiments also reveal that the orientation of 8CN is higher in stretched PDLC with a semicrystalline matrix (PCL) than with an amorphous matrix (the PCL-PVC blend), and that the sizes of the LC droplets also have a slight effect on the induced orientation. This work represents a first step in the exploration of new electrooptical effects of PDLC through the presence of a uniform orientation of the liquid crystal molecules and modifications of the polymer cavity at the electrical field-off state.Key words: polymer-dispersed liquid crystals, molecular orientation, infrared dichroism, electrooptical materials.

Viewing Angle Measurement of Polymer-Dispersed Liquid Crystal

2011 ◽  
Vol 181-182 ◽  
pp. 79-82
Author(s):  
Xing Fang Jiang ◽  
Shu Xin Wu
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Angle Measurement ◽  
Driving Voltage ◽  
Viewing Angle ◽  
Liquid Crystal Device ◽  
Polymer Dispersed Liquid Crystal ◽  
Polymer Dispersed Liquid Crystals ◽  
Voltage Dependent ◽  
Polymer Dispersed

Polymer-dispersed liquid crystals are one kind of important devices. With a He-Ne laser and a photoelectric detector, we measured the driving-voltage dependent and viewing-angle dependent transmission for a polymer-dispersed liquid crystal device. Our results showed that the polymer-dispersed liquid crystal device worked at the driving voltage of 4 V and the effective viewing angle of about 65 degree.

Infrared Switching Polymer Dispersed Liquid Crystals

1995 ◽  
Vol 413 ◽  
Author(s):  
R. A. Moody ◽  
I. H. Loh ◽  
A. Z. Hed
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Processing Parameters ◽  
Thermally Induced ◽  
Polymer Dispersed Liquid Crystals ◽  
Polymer Dispersed ◽  
Droplet Sizes ◽  
Switching Characteristics ◽  
Thermodynamic Limits ◽  
Droplet Morphology

ABSTRACTInfrared Polymer Dispersed Liquid Crystals (PDLCs) - polymethylmethacrylate host and E7 eutectic liquid crystal mixture - are formed through an adaptation of the thermally induced phase separation process, enabling facile creation of large liquid crystal droplet formation in the polymer host outside of the normal thermodynamic limits. The PDLCs were characterized electro-optically and microscopically. The effects of the processing parameters on the droplet morphology and switching efficiency are analyzed and presented for these systems. Droplet sizes up to 15 &m have been observed with efficient switching characteristics in the 3 - 5 μm range.

Sign in / Sign up

Export Citation Format

Share Document