▎ 摘　　要

NOVELTY - To-be-modified carbon nanomaterial is added to a reaction chamber, and ozone/oxygen gas mixture is subjected through solvent-containing solvent bottles and ozone decomposition is carried out. A different solvent is used to regulate the different levels of ozone decomposition. Carbon nanomaterials are modified by oxidizing for 6 hours or less times, to obtain carboxyl group-modified carbon nanomaterial. The flow rate of oxygen with respect to 1 g carbon nanotubes is 0.2-0.5 l/min. USE - Carboxyl group-modification of carbon nanomaterials e.g. graphene, carbon nanotubes, activated carbon, carbon black, carbon fibers and nano-diamond powder (all claimed). ADVANTAGE - The method efficiently provides carboxyl group-modified carbon nanomaterials by simple method without affecting the environment. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for device for carrying out carboxyl group-modification of carbon nanotubes.