The orientation of liquid crystal molecules is very sensitive towards contacting surfaces, and this phenomenon is critical during the fabrication of liquid crystal display panels, as well as optical and memory devices. To date, research has focused on designing and modifying solid surfaces. Here we report an approach to control the orientation of liquid crystals from the free (air) surface side...

Polymer dispersed liquid crystals (PDLC) are a well established technology for electrooptic devices used in displays and light switches. They rely on dispersions of nematic liquid crystal material in a polymer matrix. In the absence of an electric field, the director field n(r), which characterizes the local average orientation of the rodlike nematic mesogens, is randomly oriented, leading to a...

The nuclear-magnetic-resonance (NMR) technique is employed to liquid-crystal-dispersed-polymer (LCDP) systems. Deuterium NMR is used to determine director distributions in LCDP cells in the presence of a magnetic field. The samples consist of a nematic liquid crystal mixed with small percentages of a monomer that is polymerized under different conditions after dissolving it in the liquid crysta...

We have designed an inexpensive and sensitive mechanochromic system. Our system is prepared by a simple emulsion procedure of nematic liquid crystal in polydimethylsiloxane (PDMS). The resulting polymer dispersed liquid crystal (PDLC) exhibits a transmission change of 50% as a response to strain. Here we characterize the morphological, optical, and mechanical factors behind this transmission ch...

The polymer stabilized liquid crystal (PSLC) film is a relatively novel electro-optical material, which is generally obtained by dissolving a small amount of a bifunctional photoreactive monomer in a low molecular mass liquid crystal. In this paper, the PSLC films were prepared with photoreactive biphenyl methacrylate monomers by photopolymerization induced phase separation. The effects of liqu...

We report the fabrication and the optical characterization of a hybrid tunable integrated optical filter. It consists of a diffused ion-exchanged channel waveguide on a borosilicate glass substrate with a cover of the same glass to form a gap filled with a holographic grating. The grating morphology, called POLICRYPS (POlymer LIquid CRYstal Polymer Slices), is made of alternating stripes of pol...

Liquid crystal polymers with semiflexible polymer backbone exhibit crystalline order despite of some defects in crystal packing. Isothermal heat treatment of the polymers below and above their liquid crystalline temperatures is expected to provide the necessary energy and time for the molecular chains to overcome the defects in crystal packing and to be arranged in a more perfect crystal lattic...

In this paper, microstrip coupled line band pass filters using Koch fractal curves are proposed for the first time. These filters are fabricated on Liquid Crystal Polymer (LCP) substrate for Ku Band. Conventional microstrip coupled line filters are very popular for RF front ends because these can be made easily. However, their large 2 harmonic causes the shape of the pass band to be asymmetric ...

kevlar is one of the fbers which is used in heavy industrial productions such as, shipping, military and weaving for reinforcement of composites. initial polymer of kevlar or poly(para-phenylene terephthalamide) is an oriented liquid crystal polymer. existence of aromatic group in the main chain leads to formation of rigid-rod molecules in the polymer, high strength and high modulus in it is fb...