10 wt however it should be appreciated that the concentration of the polymer may vary depending on the desired properties and applications such as coatings of the resulting composite material preferred solvents for use in the present invention are polar solvents and include dimethyl sulfoxide acetone tetrahydrofuran n n dimethyl acetamide methanesulfonic acid and polyphosphoric acid the carbon nanofibers used in the present invention are preferably prepared in accordance with u s pat no 6 156 256 incorporated herein by reference several types of carbon nanofibers may be used in the present invention including as grown fibers pyrolytically stripped fibers and heat treated fibers by heat treated fibers it is meant that the nanofibers are fully graphitized by slowly heating the fibers to 3 000 u00b0 c and then slowly cooling the fibers it has been found that when carbon nanofibers are heat treated the order of the surface chemical vapor deposited carbon is highly increased resulting in substantially improved mechanical electronic and thermal transport properties heat treated carbon nanofibers have an electrical conductivity close to that of highly ordered pyrolytic graphite and a thermal conductivity which is five times as high as that of copper heat treated fibers are preferred in applications where high conductivity and low carbon nanofiber loading are desired the method of the present invention is preferably carried out by mixing the carbon nanofibers and the desired polymer in a solvent.