▎ 摘　　要

NOVELTY - Roll-to-roll process involves preparing a humic acid dispersion having humic acid molecules and optional graphene sheets dispersed in a liquid medium, where dispersion contains a blowing agent, where humic acid has a content of non-carbon elements less than 5% by weight, continuously or intermittently dispensing and depositing humic acid dispersion onto a surface of a supporting substrate to form a wet layer of humic acid, supporting substrate is a continuous thin film supplied from a feeder roller and collected on a collector roller, partially or completely removing liquid medium from the wet layer of humic acid to form a dried layer of humic acid in a heating zone or multiple heating zones and heat treating the dried layer of humic acid in one of heating zones containing a heating temperature from 80-500 degrees C. USE - Roll-to-roll process for producing a continuous-length sheet of the humic acid-derived foam. ADVANTAGE - The roll-to-roll process provides an improved thermal conductivity, electrical conductivity, elastic modulus, and/or strength. DETAILED DESCRIPTION - Roll-to-roll process involves preparing a humic acid dispersion having humic acid molecules and optional graphene sheets dispersed in a liquid medium, where dispersion contains a blowing agent, where humic acid has a content of non-carbon elements less than 5% by weight, continuously or intermittently dispensing and depositing humic acid dispersion onto a surface of a supporting substrate to form a wet layer of humic acid, supporting substrate is a continuous thin film supplied from a feeder roller and collected on a collector roller, partially or completely removing liquid medium from the wet layer of humic acid to form a dried layer of humic acid in a heating zone or multiple heating zones and heat treating the dried layer of humic acid in one of heating zones containing a heating temperature from 80-500 degrees C, at a desired heating rate sufficient to activate blowing agent for producing humic acid-derived foam, which is composed of multiple pores and pore walls, where pore walls contain single-layer or some-layer humic acid-derived hexagonal carbon atomic planes, some-layer hexagonal carbon atomic planes are chemically bonded to create electron-conducting pathways, have 2-10 layers of stacked hexagonal carbon atomic planes having an inter-plane spacing d002 from 0.3354 nm to 0.60 nm as measured by X-ray diffraction, and contain 0.01 to 5% by weight of non-carbon elements.