Liquid crystal polymer composed

Liquid Crystal Polymer, composed from mainly 4-hydroxybenzoic ... 

Liquid Crystal Polymer, composed from mainly 4-hydroxybenzoic acid or 6-hydroxy-2-naphthoic acid, further, depending on type p-acetaminophenol, terephthalic acid, and biphenol" ... 

A semi-flexible main chain liquid crystal polymer is composed of mesogenic units separated by flexible spacers, normally alkyl chains [ 7]. These polymers are not only of interest for their application potential [8] they are also of major fundamental interest because of their unusual liquid crystalline properties. It is well known, for example, that the transitional behaviour of a semi-flexible main chain liquid crystal polymer shows a dramatic dependence on the length and parity of the flexible spacer linking the mesogenic units [9]. Other fascinating behaviour includes the observation of a nematic-nematic transition [ 10] and the occurrence of alternating smectic phases [11-15]. 

This article explores the possibilities of using simulation to predict the formation of complex structures for two relatively simple classes of mesomorphic materials liquid crystal polymers and liquid crystal dendrimers (figure 1). In the first section of the article we discuss briefly some of the models available currently to the simulator. We then review some of our preliminary work in this area, developing hybrid models composed of a mixture of anisotropic and isotropic sites and using them to study liquid crystal polymers and dendrimers. We point also to some of the problems still faced in this area and some of the likely future developments designed to overcome them. 

Derikov YI, Kutergina lY, Shandryuk GA, Merekalov AS, Gorkunov MV, Abramchuk SS, Ezhov AA (2014) Stable non-equilibrium composites composed of liquid crystal polymers and CdSe quantum dots. Polym Sci A56(4) 488-497... 

Liquid Crystalline Polymers. One class of polymers that requires some special attention from a structural standpoint is liquid crystalline polymers, or LCPs. Liquid crystalline polymers are nonisotropic materials that are composed of long molecules parallel to each other in large clusters and that have properties intermediate between those of crystalline solids and liquids. Because they are neither completely liquids nor solids, LCPs are called mesophase (intermediate phase) materials. These mesophase materials have liquid-like properties, so that they can flow but under certain conditions, they also have long-range order and crystal structures. Because they are liquid-like, LCPs have a translational degree of freedom that most solid crystals we have described so far do not have. That is, crystals have three-dimensional order, whereas LCPs have only one- or two-dimensional order. Nevertheless, they are called crystals, and we shall treat them as such in this section. 

Another technique which uses microscopy is based on the miscibility of compounds with identical mesophases and was developed by the Halle liquid crystal group for model liquid crystals. Noel has applied this method to mixtures composed of well-known model liquid crystals with polymeric liquid crystals 3 - ). Assuming that the method is applicable to mixtures of polymers and low molecular weight compounds, the type of mesophase can be positively identified if the polymer and model are miscible. 

The side chain polysiloxane liquid crystalline polymers PI, P2 and P3 composed of the above three ferroelectric liquid crystals as the side groups exhibit the ferroelectric liquid crystal phase, their chemical formulae being respectively. 

A. Kumano, O. Niwa, T. Kajiyama, M. Takayanagi, K. Kano and S. Shinkai, Photoinduced ion permeation through ternary composite membrane composed of polymer/liquid crystal/azobenzene-bridged crown ether, Chem. Lett., 1983, 1327. 

Ubukata T, Seki T, Ichimura K. 2002. Surface relief grating in hybrid films composed of azobenzene polymer and liquid crystal molecule. Coll Surf A 198 113 117. 

The chemical structure of the polymers determines whether the molecules can form rigid rods. If the backbone of the polymer is composed of rigid structures, then it tends to form main chain liquid crystals. If, however, the side chains are rigid, then the polymer will tend to form side chain liquid crystals. 

---