The present invention provides a chemically functionalized submicron graphitic
fibril having a
diameter or thickness less than 1 μm, wherein the
fibril is free of continuous thermal carbon overcoat, free of continuous
hollow core, and free of catalyst. The
fibril is obtained by splitting a micron-scaled carbon
fiber or
graphite fiber along the
fiber axis direction. These functionalized graphitic fibrils exhibit exceptionally high electrical
conductivity, high
thermal conductivity, high
elastic modulus, high strength and good
interfacial bonding with a matrix resin in a composite. The present invention also provides several products that contain submicron graphitic fibrils: (a) paper, thin-film, mat, and web products; (b) rubber or tire products; (c) energy conversion or storage devices, such as
fuel cells,
lithium-
ion batteries, and supercapacitors; (d) adhesives, inks, coatings, paints, lubricants, and
grease products; (e) heavy
metal ion scavenger; (f) absorbent (e.g., to recover spill oil); (g) sensors; (h) friction and
brake components; (i)
radiation-shield components; (j) catalyst carrier; and (k) composite materials.