Chung Snip:
"Abstract
Carbon black dispersions based on polyethylene glycol (PEG) or di(ethylene glycol) butyl ether, along with dissolved ethyl cellulose, provide thermal pastes that are superior to solder as thermal interface materials. The thermal contact conductance of the interface between copper disks reaches 3 x 10^5 W/m2.°C, compared to 2 x 10^5 W/m2.°C for a tin-lead-antimony solder...
Materials
The polyethylene glycol (PEG, or HO(CH2CH2O)nH) used as an organic vehicle was PEG 400 from EM Science (Gibbstown, NJ). It had an average molecular weight of 400 amu; this average value corresponds to n ~ 8.68. It was a liquid at room temperature and optionally contained ethyl cellulose (E8003, Sigma Chemical Co., St. Louis, MO) at either 3 or 5 vol.%. The ethyl cellulose was a white powder that was dissolved in the vehicle. It served to improve the dispersion and suspension of the solids in the pastes....The carbon black used was Vulcan XC72R GP-3820 from Cabot Corp., Billerica, MA. This carbon black was chosen due to its electrical conductivity and easy dispersion...
Conclusions
The use of a PEG-based paste (containing 3 vol.% dissolved ethyl cellulose and dispersed carbon black in the optimum amount of 1.25 vol.%) as a thermal paste between copper disks results in a thermal contact conductance of 30 x 10^4 W/m2.°C, compared to a value of 20 x 10^4 W/m2.°C for tin-lead-antimony eutectic solder applied in the molten state...
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Easy to make once you have the ingrediants, which seem easy to get.
The full document is available for download from the link in the first post:
Chung Carbon Black
Dont forget my cut when you start selling this stuff!