Abstract:
WOOD OR OTHER VEGETABLE MATERIAL HAVING A NON-UNIFORM SHAPE SUCH AS SHAPELESS PARTICLE POWDER, FLAKY POWDER, CHIP AND THE OTHERS IS CARBONIZED IN AN ACIDIC ATMOSPHERE CONTAINING VAPOR OR GAS OF HYDROCHLORIC OR HYDROBROMIC ACID OR ITS ANHYDRIDE FOR 10 MINUTES TO 10 HOURS AT A TEMPERATURE OF 80-1200* C. TO OBTAIN ACTIVATED CARBON OF SUPERIOR ADSORPTION ACTIVITY IN VERY HIGH YIELDS. IF DESIRED, THE ACTIVATED CARBON SO OBTAINED IS HEATED FURTHER IN AN ATMOSPHERE CONTAINING AN OXIDIZING GAS SUCH AS STEAM, CARBON DIOXIDE GAS OR AIR, OR IN AN INERT ATMOSPHERE TO IMPROVE THE ADSORPTION ACTIVITY OF SAID CARBON.
Abstract:
Process for the production of a C/C composite comprising a carbon matrix and carbon fibres and exhibiting a difference in crystalline structures of the carbon matrix between (a) the part situated at the interface and in the vicinity of the interface between the carbon fibres and the carbon matrix and (b) the remainder of the carbon matrix. This C/C composite exhibits excellent mechanical strength and thermal conductivity properties. The process for the production of this C/C composite comprises the insertion of a carbonisation catalyst into the carbon fibres, the impregnation of these carbon fibres containing the carbonisation catalyst inserted therein, with a precursor of the carbon matrix, and calcination of the impregnation product.