Fig. 5.

Pyrene dyes for high yield graphene exfoliation. a-d Chemical formulas of the 4 pyrene-sulfonate dye molecules studied for LPE in water. The protonated/deprotonated groups are indicated in green. e Photographs of 4 dye solutions after sonication with graphite and compared with that in concentrated sulphuric acid. (f) Images of the respective suspensions after removal of excess dye by washing and centrifugation indicating highest concentration obtained with PS2 surfactant. g-j Snapshots from molecular dynamic simulations of pyrene sulphonate molecules adsorbing on graphene in water. a-j reproduced from ref. 52 with permission, © Royal Society of Chemistry)