TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Method: In the particle treatment for disaggregating, deagglomerating, exfoliating, cleaning or functionalizing particles, the particles to be treated are carbon particles, where the particles to be treated comprise graphite, carbon nanotubes (CNTS) or other nanoparticles. The method comprises using the contact bodies which are moveable in the treatment chamber, where the treatment chamber is a drum, preferably a rotatable drum, in which a set of the contact bodies are tumbled with the particles to be treated. The wall of the treatment vessel is conductive and forms a counter-electrode to an electrode that extends into an interior space of the treatment chamber. The glow plasma forms on the surfaces of the contact bodies or contact formations. The contact bodies are metal balls or metal-coated balls, where the contact bodies or contact formations have a diameter, and the diameter is at least 1 mm and not more than 60 mm. The pressure in the treatment vessel is less than 500 Pa. During the treatment, gas is fed to the treatment chamber and gas is removed from the treatment chamber through a filter. The treated material, that is, the particles or disaggregated, deagglomerated or exfoliated components resulting from the treatment, are chemically functionalized by components of the plasma-forming gas, forming e.g. carboxy, carbonyl, OH, amine, amide or halogen functionalities on their surfaces. The plasma-forming gas in the treatment chamber is or comprises any of oxygen, water, hydrogen peroxide, alcohol, nitrogen, ammonia, amino-bearing organic compound, halogen such as fluorine, halohydrocarbon such as carbon tetrafluoride (CF4) and noble gas. The particles comprise graphitic carbon, such as mined graphite, which is exfoliated by the treatment, and after the treatment the treated material comprises or consists of discrete graphitic or graphene platelets having a platelet thickness less than 100 nm and a major dimension perpendicular to the thickness which is at least 10 times the thickness. The treatment is continued for at least 30 minutes and/or until the treated carbon material comprises by weight at least 90% of platelets less than 100 nm thick and in which the major dimension is at least 10 times the thickness, preferably at least 100 times the thickness. The treatment is continued until the treated carbon material comprise by weight at least 80%, preferably at least 90%, of platelets less than 30 nm thick, preferably less than 20 nm thick, and in which the major dimension is at least 10 times the thickness, preferably at least 100 times the thickness. In preparing the particle dispersion or the composite material, the particles are dispersed in a matrix material which is polymeric, for example epoxy resin, polyolefin, polyurethane, polyester, polyamide or poly(meth)acrylic material or mixture or copolymer of such polymer types, or is a precursor, e.g. oligomer or monomer, of such polymer. The treated material comprises carbon nanotubes, or graphitic or graphene platelets, dispersed in the polymeric matrix material, preferably at less than 10% by weight of the composite material, to make an electrically-conductive composite material. Preferred Material: In the composite material, the particles are dispersed in a matrix material which is polymeric, for example an epoxy resin, polyolefin, polyurethane, polyester, polyamide or poly(meth)acrylic material or mixture or copolymer of such polymer types, or is a precursor, e.g. oligomer or monomer, of such polymer. EXAMPLE - No suitable example given.