Peeling,Modification And Application Of Hexagonal Boron Nitride

Hexagonal boron nitride(hBN),also called “white graphene”,there are excellent physical and chemical properties,such as strong acid and strong alkali resistance,resistance to oxidation,high temperature resistance,high thermal conductivity,mechanical strength,lubrication,and wide band gaps.Because of these characteristics,they were widely applied in aerospace,catalyst carrier,electronic packaging and lubricants.However,there is still a big problem for these applications,that is,the multilayer hexagonal boron nitride is inert and difficult to apply,so it is necessary to peel and modify the hexagonal boron nitride.In this paper,the effects of different ultrasonic methods and solvents on the peel effect of hBN were studied,and the hexagonal boron nitride was peeled and modified by ball milling,and hBN aerogels were prepared by hydrothermal method.Then hBN aerogels combined with PDMS to form polymer composites with high thermal conductivity.The specific Experimental content is as follows:(1)The effect of ultrasonic stripping parameters(including ultrasonic method,solvent type,etc.)on hBN stripping was studied,and a suitable method was found to peel hBNs.Through particle size analysis and FTIR analysis,it is concluded that the larger the polarity of solvent,the greater the water solubility of surfactant,the greater the alkalinity of Lewis base,the greater the ultrasonic power,and the better the peeling effect.(2)The modification of hBN was carried out by ball milling method,and the influence of ball milling parameters(including ball milling agent,ball milling method,etc.)on the modification effect was studied.FTIR XPS showed that the modification effect was the best when 6-aminohexanoic acid was used as ball milling agent.It was proved by Raman,particle size analysis and AFM XRD that the ball-milling method could be used to peel and modify hBNs at the same time.(3)Hexagonal boron nitride aerogels were prepared by hydrothermal method and freeze-drying method.The effects of hydrothermal parameters(including hydrothermal temperature,hydrothermal time,crosslinking agent and hBN concentration)on the properties of hBN aerogels were studied.The results showed that the best aerogel was obtained by using ascorbic acid as crosslinking agent at 80 for 24 h,and the composite ?with PDMS was prepared with high thermal conductivity.The structure and properties of aerogels were illustrated by SEM and optical photographs.The thermal conductivity of the composites was proved by thermal conductivity test.The mechanical properties of the composites were demonstrated by compression elastic test.