High-pressure synthesis of microdiamonds from polyethylene terephthalate

Polyethylene terephthalate (PET) C10H8O4, material of plastic bottles, was used as a carbon bearing precursor for high-pressure synthesis of microcrystalline diamonds. At pressure of 8-9 GPa, the diamond formation was found to start at temperatures of 1370-1470 K, which is extremely low for synthesis of microdiamond from organic compounds. Photo-luminescence of the diamond produced is characterized by emission of 2NV, NV0 and NV- centers. It was shown that carbonization of PET, presumably stimulated by the formation of water molecules, takes place in the temperature range 620-770 K with formation of graphene nanoclusters. The results obtained indicate perspectives of diamond synthesis from PET for production of microdiamonds free of metallic impurities and for recycling plastic bottles under pressing without formation of toxic products.