Preparation Of Fullerene Micro/Nano Crystals By Liquid-Liquid Interface Precipitation

Today,the construction of nanomaterials in the world has been a research hotspot.There are two design strategies for the construction of nanomaterials:"top-down"and"bottom-up"methods.The performance of nanomaterials depends on their size and morphology.In the"bottom-up"method,structural units are self-assembled at the molecular level,making it possible to design nanomaterials of different sizes and nanoscale.Fullerene C₆₀ molecules are homogeneous,and spherical,which are ideal building unit for building nanomaterials.C60 molecule self-assembly with intermolecular forces to form different fullerene crystals,which provides the possibility for achieving the unique properties of C60 molecules.It is important to study methods to effectively control the morphology of fullerene crystals.The main contents of this dissertation are as follows:1.On the basis of the liquid-liquid interface precipitation?LLIP?,spherical fullerene crystals were prepared by high-temperature treatment when the solution was mixed.The effects of different types of solvents on the crystallization of C₆₀ were compared.2.The two-dimensional hexagonal fullerene crystals prepared in a C60 toluene saturated solution/carbon tetrachloride system are converted into a solution covered on the fullerene crystals to volatilize,and a rod-like structure appears on the originally smooth surface.A comparative test of fullerene crystals in different solvent environments proposes that the fullerene crystal morphology transition mechanism is the changes in the solvent environment caused by difference in solvent evaporation speed.3.Three-dimensional massive fullerene crystals were prepared in the C60 o-xylene/n-butanol system.When dried in air,it was observed that the slender rod-like structures on the smooth surface intersect with each other,and combined with hexagonal fullerene crystals.The mechanism of transformation in air,through the accurate preparation of o-xylene/n-butanol mixed solution successfully produced cage fullerene crystals.4.In the rhombus-shaped fullerene crystals prepared by the C₆₀ toluene/t-butanol system,washing with ethanol found that the originally smooth surface became uneven,which may be a new way to prepare porous fullerene crystals.In the solvent environment,the morphology of diamond-shaped fullerene crystals to fence-shaped fullerene crystals to fibrous fullerene crystals was successfully changed.5.Inspired by the LLIP,a new method for preparing fullerene crystals is proposed,the two-solvent volatilization method.By adjusting the volume ratio of the good solvent and the poor solvent in the solution,flower-like fullerene crystals were successfully prepared.