Application Of Mechanical Ball Milling In The Study Of Carbon Nanomaterials

Carbon nanomaterials,such as fullerene,carbon nanotube and graphene are lightweight materials.Due to their unique structures and amazing properties,carbon nanomaterials are widely used in composite materials,catalysis,energy,biomedicine,and other fields.However,the original carbon nanomaterials are easy to agglomerate and their surface is hydrophobic,which results in their poor dispersibility and limits their application.The modified carbon nanomaterials not only improve the dispersibility but also can even play a better performance in many case.Therefore,the investigation of modification for carbon nanomaterials is an important field in the research of the properties and applications of carbon materials.The research work of this paper is mainly to apply the mechanical ball milling to the study of carbon nanomaterials,including the functionalization reaction of zero-dimensional fullerene and the cutting of one-dimensional carbon nanotubes,and we systematically characterize the experiment.The main contents are as follows:(1)Add the oxidant K2FeO4 to the ball milling to directly react with the original fullerene C60,and hydrolyze to obtain fullerenol.The effects of conditions such as ball milling time on the product structure,number of hydroxyl groups and morphology were studied.After ball milling for 0.5 h,1 h and 4 h and hydrolyzed,-OH was attached to the C60 cage to obtain C60(OH)12,C60(OH)18 and C60(OH)17 respectively.The oxidation reaction was completed after 1 h of ball milling.After 1 h of ball milling,there was almost no unreacted C60,and the number of-OH could not be increased significantly.The fullerenol products prepared by ball mills exist in the form of spherical nanoparticles in water,and the particle diameters are distributed in tens to hundreds of nanometers.The dispersion study shows that the solubility of HiPco carbon nanotubes in water were effectively improved with the assistance of fullerenol C60-QM-1h.The solubility of HiPco in water reached 0.175 mg/mL and 0.177 mg/mL after effective ultrasound time of 1 h and 2 h respectively with Fullerenol C60-QM-1h.(2)We prepared single-walled carbon nanotubes functionalized with alkyl groups and used as starting materials.With the difference in strength between sp2 hybridized C-C bond and sp3 hybridized C-C bond,the single-walled carbon nanotubes were cut by planetary ball milling.The effects of conditions such as alkylation,time of ball milling,speed of ball milling and the addition of auxiliary abrasive SDS on product structure and size were studied.Two types of single-walled carbon nanotubes(HiPco and SWNT(6,5))were used for comparison.The results show that the mechanical ball milling can effectively cut and obtain short single-walled carbon nanotubes,but it will not damage the sp2 region.Speed of ball milling at 250 r/min and 600 r/min for 10 h can obtain short single-walled carbon nanotubes with lengths of 1?5 ?m and 1?3 ?m,respectively.When SDS is added,short carbon nanotubes with a length of less than 1?m are obtained by ball milling for merely 2 h.Through simple heat treatment,the alkyl chain on the surface of the carbon nanotubes can be effectively removed without destroying the surface structure of the carbon nano tubes.