Macrocrystalline diamond monocrystal synthesis from graphite - by polymerising and applying required external electrostatic field

摘要

Synthesis of macrocrystalline diamond monocrystals (I) is carried out by converting graphite monocrystals (II) (9) or graphite blocks (9) of highly oriented pyrographite into (I) by polymerisation, by applying an external electrostatic field to give the free reaction enthalpy of polymerisation at approx. room temp. and atmos. pressure a negative sign. Pref. cationic polymerisation is carried out, using a Lewis acid initiator, which has max. polarisability and a Van-der-Waals radius of min. 1.3 A and max. 2.2 Angstroms; and/or polymerisation is initiated by I2, pref. in a 5 (wt.)% petroleum ether soln. USE/ADVANTAGE - The cost of the appts. used is minimised, since the reaction can be carried out at room temp. and atmos. pressure by applying a field of ca. 2.5-6.5 MV/cm. Large (I) can be produced, e.g. crude (I) cylinders with a dia. of 4.4 cm and height of 2.9 cm.