Polysiloxane-modified Tetraphenylethene And Imidazole Derivatives:Synthesis,Characterization

Tetraphenylethene is a common molecule with aggregation induced luminescence(AIE).Tetraphenylethene is simple in structure and easy to synthesize.The emission of blue light from the tetraphenylethene in electroluminescence and it has good fluorescence quenching rate toward detection of explosives.In order to solve the thermal stability and film forming property of tetraphenylethene,siloxane was introduced into the main chain of the polymer.The synthesized polymers could not change the photophysical properties and AIE properties of tetraphenylethene.Polymer materials with a high thermal stability could greatly improve the performance and lifetime of organoelectronic devices and fluorescence sensor.Silicone as the polymer backbone mainly has a good film-forming,and very good flexibility.Monomer is successfully synthesized by attaching tetraphenylethene(TPE)units onto siloxane by Heck reaction and a polysiloxane with TPE(PTPESi)pendants has been successfully obtained by polycondensation.We tested PTPESi and monomer UV and PL.Polysiloxane does not change the UV and PL of TPE.Cyclic voltammetry(CV)analysis of PTPESi were measured.Polymer fluorescent behavior in THF/water mixtures is studied through PL emission.With 90 vol%water content,the PL intensity is 1334-fold higher than that in the pure THF solution.Compared the polymer and monomer of DSC and TGA,thermal properties of PTPESi has been a huge upgrade.The high photoluminescent stability of PTPESi film is also confirmed.PTPESi by annealing experiment displays good film-forming ability and high morphological stability with small RMS as revealed by AFM.PTPESi film displays high fluorescence quenching efficiency and reversibility toward vapor-phase detection of the six explosives,so it will be used as a good sensor.Finally,we design the OLED device structure,and test the performance of the device.The electroluminescence of the device is very stable.In order to improve the thermal stability and film forming properties of the electron transporting materials.Benzimidazole is attached to the methylvinyldiethoxylsiloxane by typical Heck coupling and the target polymer PPBISi is synthesized from polycondensation.We tested PPBISi UV and PL.HOMO(-5.88 eV)and LUMO(-2.53 eV)of PTPESi were measured by cyclic voltammetry test.Thermal stability was significantly improved by DSC and TGA.PPBISi shows good film-forming ability and high morphological stability with small RMS by AFM.