Fig. 1
Preparation of ultra-high concentration graphene in water. a Conventional liquid-phase exfoliation where graphene flakes are peeled off from graphite and dispersed in an organic solvent, yielding low concentration dispersion in low yield because of the limited stability of the dispersion. b Our non-dispersion strategy for graphene production in water. Pretreated graphite is exfoliated by high-rate shearing and subsequently flocculated in alkaline water, producing graphene slurry on a large scale (100 g), high yield (82.5 wt%), and ultra-high concentration (50 mg mL−1). c Comparison of concentration, yield, and production scale of non-dispersion strategy with other liquid-phase exfoliation strategies (shearing9, ultrasonic15,16,21, microwave12,18, and chemical intercalation5,24,25-assisted exfoliation)
