Preparation And Property Of Liquid Crystalline Gold Nanoparticles With Azobenzene Mesogens

In this thesis,the photo-responsive azobenzene mesogen and the polymer with azaobenzene mesogene were chosen to prepare two kind of liquid crystal gold nanoparticle,the self-assembly and photo-responsive behavior of gold nanoparticles was studied.Furthermore,we also studied that the type of nanoparticles by light stimulation was also directed the orientation behavior of nematic liquid crystal.The content can be classed into two sections:1.A series of Au@AzoC₆ were successfully synthesized using the designed thiol sealing side containing azobenzene liquid crystal unit molecular ligand（AzoC₆-SH）via Brust-Schiffrin method.1H NMR,TEM,TGA results indicated the content of gold and the size of the nanoparticles.DSC,POM,WAXD,Gi-WAXD results showed that with the gold content increas,the liquid crystal gold nanoparticle show different phase structure.With the increase size of gold nanoparticles,the supramolecular structure occurred by the lamellar phase to the columnar phase and transformation to the more complex advanced orderly structure.The UV-Vis results showed that the nanoparticles had the photo-responsive but the supramolecular structure did not change in illumination.In addition,controlling the liquid crystal gold nanoparticles reversible orientation of nematic liquid crystal was studied.2.A liquid crystalline polymer ligand containing azobenzene mesognes was synthesized,which was further used to synthesize a series of the Au@TE-PAzo gold nanoparticles of different gold content by Brust-Schiffrin method.Similary,we used 1H NMR,TEM and TGA test to confirm the content of gold and the size of the Au@TE-PAzo gold nanoparticles.And DSC,POM,SAXS were used to explore the phase behavior and phase structure.With increasing the content of Au wt%,the birefringence phenomenon of nanoparticle have weakened.Moreover,the light responsive of Au@TE-PAzo–n gold nanoparticles via UV-Vis was investigated.The series of Au@TE-PAzo gold nanoparticles was used as molecular brushes to control the orientation of 5CB.Furthermore,while the Au@TE-PAzo gold nanoparticles doped a of nematic liquid crystal mixtures,the Au@TE-PAzo series gold nanoparticles could reversibly control nematic liquid crystal orientation.