Hexagonal boron nitride compositions characterized by interstitial ferromagnetic layers, process for preparing, and composites thereof with organic polymers
AssigneeE. I. Du Pont de Nemours and Company
InventorSalah Boussaad
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Abstract
The present invention relates to a hexagonal boron nitride platelet particle having a layer of a ferromagnetic metal between the layers of hexagonal boron nitride thereof, and a process for preparing the composition thereof. The present invention further relates to polymeric composites formed therefrom. The present invention describes improvements in thermal conductivity of said composites when subject to an orienting magnetic field.
Claims20
A composition comprising modified hexagonal boron nitride (hBN) particles comprising a plurality of registered layers of hexagonal boron nitride and a ferromagnetic metal interstitially disposed between said layers of boron nitride.
A film comprising an organic polymer and modified hexagonal boron nitride particles dispersed therewithin, said modified hexagonal boron nitride particles comprising a plurality of registered layers of hexagonal boron nitride and a ferromagnetic metal interstitially disposed between said layers of boron nitride.
A process for obtaining modified hexagonal boron nitride particles comprising a plurality of registered layers of hexagonal boron nitride and a ferromagnetic metal interstitially disposed between said layers of boron nitride, the process comprising the steps:
- (a) combining an aqueous solution of a salt of a ferromagnetic metal and NH4OH in a molar ratio of metal to NH4+ in the range of 1:10 to 10:1 to form an aqueous solution;
- (b) combining hexagonal BN in particulate form with the solution so formed to form a slurry;
- (c) drying said slurry;
- and
- (d) annealing said dried slurry in a reducing atmosphere at a temperature in the range of ca. 300° C. for a minimum exposure period of 60 min to ca. 900° C. for a minimum exposure period of 5 min.
Dependencies are inferred from the claim text.