High pressure and high temperature induced polymerization of C60 quantum dots

We synthesized C60quantum dots(QDs) with a uniform size by a modified ultrasonic process and studied its polymerization under high pressure and high temperature(HPHT).Raman spectra showed that a phase assemblage of a dimer(D) phase(62 vol%) and a one-dimensional chain orthorhombic(O) phase(38 vol%) was obtained at 1.5 GPa and 300℃.At 2.0 GPa and 430℃,the proportion of the O phase increased to 46 vol%,while the corresponding D phase decreased to 54 vol%.Compared with bulk and nanosized C60,C60QDs cannot easily form a high-dimensional polymeric structure.This fact is probably caused by the small particle size,orientation of the disordered structure of C60QDs,and the barrier of oxide function groups between C60molecules.Our studies enhance the understanding of the polymerization behavior of low-dimension C60nanomaterials under HPHT conditions.