Preparation And Properties Of Functionalizatian Flexible Polymer Janus Nanosheets

Janus material has wide application prospects and has attracted the attention of researchers because of its unique asymmetric properties.The polymer Janus sheet material has both the asymmetry of Janus material and the flexibility and plasticity of the polymer,furthermore,the flaky morphology of the polymer Janus sheet enhances its asymmetric properties.In this paper,the plasticity of polymer Janus sheet material is used to increase the temperature response and ion response of polymer Janus sheet.Firstly,the temperature responsive polymer Janus nanocapsules were prepared by template method,and the Janus nanosheets were obtained by crushing the template.The Janus nanosheets were verified to be responsive to temperature and could be used as a particle emulsifier to stabilize oil/water emulsions.Main work contents are as follows:1.This article used the St?ber method to synthesis the SiO₂ nanoscale microspheres,which was served as the sacrificial template.Then,after the amination modification and brominated modification,macromolecular ATRP initiator was synthesised successfully.We grafted the poly(tert-butyl methacrylate（PtBMA）which was hydrophobic by ATRP.Then,the temperature responsive polyethylene caprolactam（PNVCL）was also grafted onto the template by ATRP.N,N-methylene double acrylamide（MBA）was used as crosslinking agent.After these two-steps graftes,we synthesised the SiO₂ composite nanometer microspheres successfully.Finally,we got the janus nanocapsules by etching SiO₂ nanometer microspheres with hydrofluoric acidand and after the ultrasonic broke,we achieved the temperature responsive Janus nanosheets.FT-IR,Zeta potential,EDX,TGA,SEM and TEM were used to characterize the morphology and structure of Janus nanosheets.Through the adjustment of the temperature conditions to verify the temperature response of Janus nanosheeet.Under the different temperature conditions,the change of the dispersion of ultrapure water was observed from the microscopic observation.The different morphology change of Janus nanoscale sheets under the different temperature conditions was observed by the scanning electron microscopy（SEM）.They all proved that Janus nanosheets is temperature responsive.Adjustment of the temperature measurement was used to test the emulsify performance of Janus nano macromolecule particles in oil and water emulsion,when the temperature of the environment is suitable to observed its emulsifying properties by optical microscope,changing the temperature,observing the emulsifying properties of detection caused by the temperature responsive attenuation until reach the effect of demulsification.2.Firstly,we synthesized 1-vinyl-3-ethyl bromide（EVImBr）imidazole ionic liquids.Then used the SiO₂ nanoscale microspheres after amino modified,continue to hydroxylation modification.The hydroxyl groups on the surface of the SiO₂ nanoscale microspheres induced the caprolactone ring opening polymerization,grafting with hydrophobic properties of poly caprolactone（PCL）whose end of hydroxyl brominated modification form macromolecular as ATRP initiator.And then grafted poly brominated 1-3-ethyl vinyl-imidazole ionic liquids（PEVIm Br）by ATRP,N,N-methylene double acrylamide（MBA）was used as crosslinking agent.Then,we synthesised SiO₂ composite nanometer microspheres.After etching away SiO₂ template with hydrofluoric acidand,ionic liquid based Janus nano hollow microspheres was finally synthesised.Ionic liquid based Janus nanometer hollow microspheres were broken with ultrasonic cell crusher,ionic liquid based Janus nanosheets were achieved.