Synthesis And Self - Assembly Behavior Of Diphenylsulfone And Star Pentaerythritol Derivatives

Soft matter has attracted great attention because of its complex self-assembled structures which have great potential applications in many areas of advanced functional materials. Soft materials include liquid crystals (LCs), gel, film, polymers and so on. Among them, LCs, combining the crystalline anisotropy order and the liquid isotropic mobility at the molecular level, have a sensitive stimuli-responsive behavior to the different external stimulation, which made LCs widely used in LCD, sensors, molecular catalysis and other new material field. Further more, the gel can self-assemble into various complex three-dimensional network structures in different solvents, and has great potential applications in the field of sensors, nano-devices, the template molecule and the drug release. Therefore, a futher study of self-assembly behavior of liquid and gel will play an important role in promoting the application of these two new types of materials.Banana LCs molecules have an unique bent-shaped structure and can self-assemble into complex liquid-crystalline structures which exhibit some excellent photoelectric properties such as ferroelectric/antiferroelectric properties, etc., therefore, these LCs have good prospects as new functional materials. Diphenyl sulfone unit, having good thermal stability and strong dipole interactions, has been successfully used in the design of symmetrical polycatenar LCs. In order to further study the self-assembly behavior of asymmetric molecules containing diphenyl sulfone unit, a series of asymmetric bent-shaped diphenyl sulfone derivatives containing cholesterol unit have successfully designed and synthesized in the thesis. Their liquid crystalline properties were investigated by POM and DSC, and their gel properties in different organic solvents were also investigated. The results showed that all these compounds except A and C2/12could form a complex three-dimensional cubic phase. But compound C1/12and A trans formed organic gel in different polarity solvents. Such properties of these compounds greatly improved their potential applicationIn addition, we also designed and synthesited a class of pentaerythritol as the central unit of the star-shaped liquid crystal molecules, and liquid crystal properties were studied. It was found that these compounds can form a complex three-dimensional cubic phase. With the change of the length and the number of the alkyl chain, the liquid crystal properties of the compounds can be changed. All the compounds have low melting points and wide range mesophases. As a result the practical application of the liquid crystal capacity will be improved.This study will further enrich the self-assembly theory in diphenyl sulfone and pentaerythritol based liquid crystal molecules.