Mpeg dspe

Example 9

C222 sample was synthesized following Simpson et al., reference 35, and, as above, was almost insoluble in any solvent. About 10 mg of this material was ground for 3 min. The resulting sample was then treated with oleum (about 20 ml) at room temperature for a day. After dilution of the acid to 500 ml solution, sodium carbonate was used to neutralize the solution. The resulting sample was centrifuged down from water solution at 5000 g for 15 min. Then the sample was transferred to DMF and sonicated using a bath sonicator in DMF (5 mL) solution of TBA (65 μl) for 15 mins. The suspension was put at room temperature for 3 days to let the TBA fully inserted into graphene layers. Then the suspension was bath-sonicated with DSPE-mPEG (Laysan Bio. Inc., Arab, Ala.) (15 mg) for 15 min., forming a homogeneous suspension. After centrifuging the suspension at 24000 g for 1 hr, a black suspension with C222 (dispersed by the surfactants, probably with sulfurate groups at the edges) retained in the supernatant was obtained.

Example 6

Natural graphite flakes (Superior Graphite Co., ˜10 mg) were ground with NaCl crystallites for 3 mins forming a uniform grayish mixture. Small pieces of graphite flakes were separated and collected by dissolving NaCl with water and filtration. The resulting sample was then treated with oleum (about 5 ml) at room temperature for a day. After complete removal of acid by filtration and repeated washing, the resulting sample was ultra-sonicated using a cup-horn sonicator in DMF (10 mL) solution of TBA (130 μl) for 5 mins. The suspension was put at room temperature for 3 days to allow the TBA to fully be inserted into the graphene layers. Then, 5 mL of the suspension was taken out and bath-sonicated with DSPE-mPEG (Laysan Bio. Inc., Arab, Ala.) (15 mg) for lhr forming a homogeneous suspension. After centrifuging the suspension at 24000 g for 3 mins, we obtained black suspension with mostly single layer GS retained in the supernatant.