Enhanced directional conductivity of graphitizable foam
View Patent ↗A graphitizable carbon foam having enhanced directional thermal conductivity is provided. The mesophase portions of a mesophase pitch are aligned with each other to create an oriented mesophase pitch, which is then foamed to provide an oriented pitch foam. The pitch foam can be heated to carbonize the pitch thereby forming an oriented carbon foam. The carbon foam can be further heated to provide an oriented graphite foam.
1. A process for manufacturing a carbon foam with enhanced directional thermal conductivity, comprising:
(a) providing a mesophase pitch having mesophase portions, each mesophase portion comprising layer planes of aligned molecules;
(b) aligning the layer planes of the mesophase portions of the mesophase pitch with each other to create an oriented mesophase pitch by exposing the mesophase pitch to a magnetic field;
(c) foaming the oriented mesophase pitch thereby forming an oriented pitch foam with enhanced thermal conductivity in directions corresponding to the orientation of the layer planes of the mesophase portions of the mesophase pitch; and
(d) heating the oriented pitch foam to a temperature sufficient to carbonize the pitch, thereby forming an oriented carbon foam.
2. The process of claim 1 , further comprising:
graphitizing the oriented carbon foam of step (d).
3. The process of claim 1 , wherein:
step (b) further comprises providing relative rotation between a molten mesophase pitch and a magnetic field.
4. The process of claim 3 , wherein:
step (a) comprises forming the mesophase pitch while providing relative rotation between the mesophase pitch and the magnetic field, so that steps (a) and (b) occur at least partially simultaneously.
5. The process of claim 3 , wherein:
step (c) is conducted while providing relative rotation between the mesophase pitch and the magnetic field.
6. The process of claim 3 , wherein:
step (d) is conducted while providing relative rotation between the oriented pitch foam and the magnetic field.