provided minutes. Phase separation was accelerated by centrifugation at 4000 RPM for 10 minutes, then the black pellets from both centrifuge tubes were combined in a speed mix cup and placed in a vacuum chamber for 30 minutes to remove isopropanol. Then, 400 mg DMF and 55 mg NMP were added, and the mixture mixed in a planetary mixer (SpeedMixer DAC 600.2; FlackTek, Inc.) for a total of 6 minutes at 2000 RPM. The mixture was subjected to 2 more cycles of (30 minutes vacuum, 6 minutes mixing at 2000 RPM) to afford the graphene nanocomposite ink as a tacky, black viscoelastic liquid.