Development of Liquid-phase Carbon Coating for Functionalizing Inorganic Particles

A liquid-phase carbon coating for inorganic particle functionalization has been developed using a novel soluble carbon material (SCM). Conventional carbon materials suffer from poor solubility and strong aggregation, limiting their use in thin and uniform coatings on fine particles. SCM, designed via bottom-up carbonization of phloroglucinol as precursor which was high reactive oxygen-containing aromatic compound, exhibits high solvent solubility and a two-dimensional nanocarbon structure. In the solvents, SCM spontaneously adsorbs onto inorganic particle surfaces through electrostatic and coordination interactions, forming an ultrathin, uniform, and mechanically stable carbon layer, typically thinner than 1 nm. The coating process is self-limiting at nearly a monolayer level, enabling precise thickness control. Post-heat treatment allows tunable carbonization, providing continuous control over surface polarity and electrical conductivity. This method is applicable to a wide range of inorganic materials, including metals, oxides, nitrides, and carbides, across nano- to micrometer-sized particles. Representative applications demonstrate improved dispersibility, lubricity, powder flowability, packing density, and sintering behavior, highlighting the broad potential of this technology in advanced materials processing.