▎ 摘　　要

NOVELTY - Producing (M1) graphene from a microwave-expandable un-exfoliated graphite or graphitic carbon, comprises: (a) supplying and feeding a powder of the microwave-expandable un-exfoliated graphite or graphitic carbon onto a non-metallic solid substrate surface; (b) moving the ribbon-shape powder into a microwave applicator chamber containing a microwave power zone (54) having a microwave application width and a microwave penetration depth, where the microwave application width is no less than the first ribbon width and the microwave penetration depth is no less than the first ribbon thickness so that entire ribbon-shape powder receives and absorbs microwave power with power level for length of time to exfoliate and separate microwave-expandable un-exfoliated graphite or graphitic carbon for producing graphene sheets that occupy expanded volume; and (c) moving the graphene sheets out of the microwave chamber, cooling the graphene sheets, and collecting the graphene sheets. USE - The methods and system are useful for producing graphene from the microwave-expandable un-exfoliated graphite or graphitic carbon (all claimed). ADVANTAGE - The methods and system: provide the shortened process time and less energy consumption; and produce ultra-thin graphene sheets (mostly single-layer graphene or a mixture of single-layer and few-layer graphene sheets) and does not require extra steps to separate graphene sheets from un-exfoliated graphite powder. DETAILED DESCRIPTION - Producing (M1) graphene from a microwave-expandable un-exfoliated graphite or graphitic carbon, comprises: (a) supplying and feeding a powder of the microwave-expandable un-exfoliated graphite or graphitic carbon onto a non-metallic solid substrate surface, where the powder is in a ribbon shape having a first ribbon width and a first ribbon thickness; (b) moving the ribbon-shape powder into a microwave applicator chamber containing a microwave power zone (54) having a microwave application width and a microwave penetration depth, where the microwave application width is no less than the first ribbon width and the microwave penetration depth is no less than the first ribbon thickness so that the entire ribbon-shape powder receives and absorbs microwave power with a power level for a length of time to exfoliate and separate the microwave-expandable un-exfoliated graphite or graphitic carbon for producing graphene sheets that occupy an expanded volume having a second width, greater than the first ribbon width, and a second thickness, greater than the first ribbon thickness; and (c) moving the graphene sheets out of the microwave chamber, cooling the graphene sheets, and collecting the graphene sheets. INDEPENDENT CLAIMS are also included for: (1) producing (M2) graphene from a microwave-expandable un-exfoliated graphite or graphitic carbon, comprising (a1) supplying and feeding a volume of the microwave-expandable un-exfoliated graphite or graphitic carbon powder onto a solid substrate surface, where the powder volume has a maximum width and a maximum thickness, (b1) moving the powder into a microwave applicator chamber containing a microwave power zone having a microwave application width and a microwave penetration depth, where the microwave application width is no less than the maximum width of the powder volume and the microwave penetration depth is no less than the maximum thickness of the powder volume so that the entire powder volume receives and absorbs microwave power with a sufficient power level for a sufficient length of time to exfoliate and separate the microwave-expandable un-exfoliated graphite or graphitic carbon into graphene sheets that occupy an expanded volume having a second width, greater than the maximum width, and a second thickness, greater than the maximum thickness, and (c1) moving the graphene sheets out of the microwave chamber, cooling the graphene sheets, and collecting the graphene sheets; and (2) a focused microwave-based system comprising (a1) solid powder-feeding and guiding means that supplies and feeds the ribbon-shape powder of the microwave-expandable un-exfoliated graphite or graphitic carbon onto a non-metallic solid substrate surface, (b1) a conveyor device, in working relation to the powder-feeding and guiding device and supporting or containing the non-metallic solid substrate, moves the ribbon-shape powder into at least a microwave applicator chamber, and (c1) a microwave power supply and power-focusing sub-system that induces a microwave power zone in the microwave application chamber, where the microwave power zone has a microwave application width, no less than the first ribbon width, and a microwave penetration depth, no less than the first ribbon thickness, so that the entire ribbon-shape powder receives and absorbs microwave power to form graphene sheets via microwave heat-activated exfoliation and separation of the powder, and (d1) a collector (66) to collect the graphene sheets. DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the focused microwave-based system. Vacuum-assisted feeder (52) Microwave power zone (54) Cooling zone (62) Exit (64) Collector (66)