Preparation And Applicantion Of Functional Composite Microspheres By Pickering Emulsion Polymerization

Core-shell composite microspheres are generally composed of two substances with different structures connected by physical or chemical processes.Therefore,core-shell composite microspheres combine the properties of two or more different substances to achieve the versatility of materials.However,core-shell composite microspheres prepared by Pickering template method can be designed and modified according to their own wishes,so the research on preparation of functional composite microspheres by Pickering emulsion template method has important theoretical significance and application value.In this paper,Polymer/graphene compsited microspheres were prepared by means of Pickering emulsion templated.The structure and morphology of polymer microspheres under different preparation conditions were also emphatically explored.Subsequently,core-shell microspheres with PANi as shell and polymer compsite microspheres as core were prepared by using the polymer compsite microspheres as templates.1.By using the improved Hummers method,graphene oxide?GO?was prepared as the stablizer of styrene/water Pickering emulsion and then the oil phase was initated by AIBN to polymerize.a special structure microsphere with GO as shell and PSt as core was successfully prepared.The structure and morphology of GO and PSt/GO composite microspheres were characterized by FTIR,XRD,Raman,DLS,TGA,DSC,SEM and contact angle,In addition,we explored the effects of the condition of GO solid particle concentration,type of initators,reaction conditions?temperature and gas atmosphere?on the structure and morphology of PSt/GO composite microspheres.The results showed that the Pickering emulsion prepared by GO is not stable but could polymerize to form a stable PSt/GO latex system.When the dosage of GO was 0.3wt%,the thermal decomposition temperature?Ti?of PSt/GO compsite microspheres was increased by 10 ^oC compared with PSt microspheres.2.The surface hydrophobic modification of GO?NGO?modified by laurylamine was dispersed in styrene by ultrasonic wave.And then the styrene with NGO-water Pickering emulsion was prepared by adding the surface hydrophobic modification of SiO₂?HSiO₂?modified by HDMS.After that,the oil phase was initated by AIBN to polymerize.As results,the special structure microsphere with SiO₂ as shell and PSt/NGO as core was successfully prepared.The structure and morphology of HSiO₂?NGO and HSiO₂/PSt/NGO composite microspheres were characterized by FTIR,XRD,Raman,TGA,SEM,TEM,and we explored the stability of Pickering emulson and the effects of the solid particle concentration of HSiO₂,type of initators and water phase pH on the structure and morphology of PSt/GO composite microspheres.What's more,the mechanism of the Pickering emulsion polymerization was discussed based on the results.The results showed that the stability of Pickering emulsion was improved when the water phase was pH=3 and the concentration of HSiO₂ particles was large.The Ti of HSiO₂/PSt/NGO composite microspheres was increased by 40^oC,compared with PSt microspheres.3.The PANI/graphene hollow microspheres were successfully prepared using the HSiO₂/PSt composite microspheres as templates.FTIR,XRD,Raman,TGA,SEM,TEM was used to investigated the structure and morphology PANi/graphene hollow microspheres,and we also explored the effect of the ratio of Aniline/PSt,the amount of initiator and PGO on the structure and morphology PANi/graphene hollow microspheres.The results showed that the surface morphology of PANi hollow microspheres could be effectively changed by simply controlling the ratio of Aniline/PSt,and PGO could effectively connect to the surface of PANi hollow microspheres.Both the hollow structure of PANi and the introduction of PGO could increase the electrochemical activity of PANi.