초록 ▼

A process for producing a carbon foam heat sink is disclosed which obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly alig

A process for producing a carbon foam heat sink is disclosed which obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly aligned graphic structure in the struts. The foam material can be made into a composite which is useful in high temperature sandwich panels for both thermal and structural applications. The foam is encased and filled with a phase change material to provide a very efficient heat sink device.

대표청구항 ▼

1. A carbon foam containing a phase change material in at least some of its pores, wherein the foam is an essentially graphitic carbon foam, further comprising an encasement layer disposed on said foam to prevent loss of the phase change material when said phase change material is in a liquid or gas

1. A carbon foam containing a phase change material in at least some of its pores, wherein the foam is an essentially graphitic carbon foam, further comprising an encasement layer disposed on said foam to prevent loss of the phase change material when said phase change material is in a liquid or gaseous state. 2. The carbon foam of claim 1 wherein said phase change material is selected from the group consisting of water, acetic acid, paraffin wax, germanium, and germanium-silicon. 3. The carbon foam of claim 1 wherein the carbon foam is a non-oxidatively stabilized foam derived from a mesophase pitch, the carbon foam having an open cell structure and a bulk thermal conductivity from about 58 W/m·K to about 106 W/m·K. 4. The carbon foam of claim 1, wherein the foam provides a specific thermal conductivity greater than about 109 W·cm 3 /m·K.g. 5. The carbon foam of claim 1 wherein the carbon foam is a non-oxidatively stabilized foam derived from a mesophase pitch, the carbon foam having an open cell structure and a specific thermal conductivity greater than copper. 6. The carbon foam of claim 5 having a specific thermal conductivity greater than four times that of copper. 7. The carbon foam of claim 6 characterized by an X-ray diffraction pattern having an average d002 spacing of about 0.336. 8. The carbon foam of claim 1 wherein the foam provides a specific thermal conductivity from about 109 W·cm 3 /m·K.g to about 200 W·cm 3 /m·K.g. 9. The carbon foam of claim 8 characterized by an X-ray diffraction pattern substantially as depicted in FIG. 14 . 10. The carbon foam of claim 8 having an open cell structure with graphite aligned along the cell wall axes, said carbon foam being derived from a mesophase pitch. 11. The carbon foam of claim 8 derived from a mesophase pitch. 12. The carbon foam of claim 1 wherein the foam provides a specific thermal conductivity greater than copper. 13. The carbon foam of claim 12 characterized by an open cell pore structure substantially comprised of ellipsoidal pores. 14. The carbon foam of claim 13 characterized by an X-ray diffraction pattern exhibiting relatively sharp doublet peaks at 2θ angles between 40 and 50 degrees. 15. The carbon foam of claim 14 derived from a mesophase pitch. 16. The carbon foam of claim 1 wherein the foam provides a specific thermal conductivity greater than four times that of copper. 17. The carbon foam of claim 16 characterized by an X-ray diffraction pattern exhibiting relatively sharp doublet peaks at 2θ angles between 40 and 50 degrees and an average d002 spacing of about 0.336. 18. The carbon foam of claim 16 characterized by an open cell pore structure substantially comprised of pores whose planar cross-sectional images are substantially circular or elliptical. 19. The carbon foam of claim 18 derived from a mesophase pitch. 20. The carbon foam of claim 19 characterized by an X-ray diffraction pattern substantially as depicted in FIG. 14 . 21. The carbon foam of claim 1 wherein the foam provides a bulk thermal conductivity greater than about 58 W/m·K. 22. The carbon foam of claim 21 having an open cell pore structure. 23. The carbon foam of claim 22 wherein the open cell pore structure is substantially comprised of ellipsoidal pores. 24. The carbon foam of claim 23 characterized by an X-ray diffraction pattern substantially as depicted in FIG. 14 . 25. The carbon foam of claim 23 characterized by an X-ray diffraction pattern having an average d002 spacing of about 0.336. 26. The carbon foam of claim 1 wherein the foam provides a bulk thermal conductivity from about 58 W/m·K to about 106 W/m·K. 27. The carbon foam of claim 26 characterized by an X-ray diffraction pattern exhibiting relatively sharp doublet peaks at 2θ angles between 40 and 50 degrees. 28. The carbon foam of claim 27 characterized by an open cell pore structure substantially comprised of ellipsoidal pores. 29. The carbon f oam of claim 28 further characterized by graphite substantially aligned along the axes of the cell walls. 30. A carbon foam containing a phase change material in at least some of its pores, wherein the foam is an essentially graphitic carbon foam and wherein the foam provides a specific thermal conductivity greater than about 109 W·cm 3 /m·K.g. 31. The carbon foam of claim 30 characterized by an open cell pore structure substantially comprised of pores whose planar cross-sectional images are substantially circular or elliptical. 32. The carbon foam of claim 30 characterized by an X-ray diffraction pattern having an average d002 spacing of about 0.338 and exhibiting relatively sharp doublet peaks at 2θ angles between 40 and 50 degrees. 33. The carbon foam of claim 30, further comprising an encasement layer disposed on said foam to prevent loss of the phase change material when said phase change material is in a liquid or gaseous state.