Conversion of carbon-graphite fibers to fibers of graphite oxide

Graphite fibers were chemically oxidized in the liquid phase to fibers of graphite oxide. Initial resistivity increases as high as 10 4 were obtained but, when the oxidized fibers were exposed to the atmosphere, resistivities decreased again and reached an apparently steady state value of about 10 3 times the resistivity of the starting fibers. In one experiment the initial increase in resistivity amounted to a factor of 10 6. The best results were obtained on the most highly graphitized fibers. Electrochemical oxidation yielded a lower resistivity increase, about ten times, but provided a controllable method of synthesis and an insight into the mechanism of reaction. The oxidized fibers retained 84% of the tensile strength and 81% of the modulus of the pristine fibers.