A non-dispersion strategy for large-scale production of ultra-high concentration graphene slurries in water

Abstract

It is difficult to achieve high efficiency production of hydrophobic graphene by liquid phase exfoliation due to its poor dispersibility and the tendency of graphene sheets to undergo π−π stacking. Here, we report a water-phase, non-dispersion exfoliation method to produce highly crystalline graphene flakes, which can be stored in the form of a concentrated slurry (50 mg mL−1) or filter cake for months without the risk of re-stacking. The as-exfoliated graphene slurry can be directly used for 3D printing, as well as fabricating conductive graphene aerogels and graphene−polymer composites, thus avoiding the use of copious quantities of organic solvents and lowering the manufacturing cost. This non-dispersion strategy paves the way for the cost-effective and environmentally friendly production of graphene-based materials.

Superhigh Electromagnetic Interference Shielding of Ultrathin Aligned Pristine Graphene Nanosheets Film

“…[ 21–25 ] Moreover, the mass production of PG nanosheets is much easier than MXenes. However, unlike MXenes, PG nanosheets suffer from poor dispersion and processability due to their chemically inert surface, [ 26,27 ] which make the synthesis of freestanding films and polymer composites very difficult. Therefore, PG has been rarely used so far for EMI shielding application.…”

Graphene synthesized in atmospheric plasmas—A review

“…57,109 Similarly, the LPEG production process requires multiple steps, significant water, and hazardous chemicals. A number of liquid-phase exfoliation techniques use chemicals such as sulfuric acid, 110,111 nitric acid, 106 chlorohydric acid, 101 and CrO 3 101 to prepare graphite for exfoliation. Significant quantities of solvent are then needed to exfoliate expanded graphite and to purify and disperse LPEG.…”

“…Significant quantities of solvent are then needed to exfoliate expanded graphite and to purify and disperse LPEG. 111 Current liquid-phase exfoliation techniques require at least 1 ton of solvent to disperse 1 kg of graphene, 111 which is neither beneficial to the environment nor economically feasible. Reducing the amount of solvent used in LPEG production results in the re-stacking of monolayer flakes by van der Waals interactions.…”

“…A non-dispersion strategy was recently developed to enable the mass production of graphene slurries, but even this method requires multiple steps, hazardous chemicals, and large amounts of water just to produce gram-scale quantities of graphene. 111 Once produced, LPEG is typically stored in a solvent or water, 111 and the use of LPEG powder in a number of graphene applications requires techniques to separate flakes from solvents, such as filtration. 101,106,108,111 Once separated from solvent, LPEG powder must be washed with purified water to remove any residual chemicals from the flakes.…”

Protection of Mild Steel by Waterborne Epoxy Coatings Incorporation of Polypyrrole Nanowires/Graphene Nanocomposites

“…Graphene was prepared by following the method by Dong et al [29]. In brief, 100 g KMnO 4 (1 wt % equiv.)…”