Patterns of solution-processed graphene oxide produced by a transfer printing method

We use a simple and all-aqueous method, transfer printing, to pattern solution-processed graphene oxide (GO). We took advantage of the naturally charged property of GO, which were prepared using the Hummers' method, to pattern it on the SiSiO ₂ substrates which were pre-soaked in polyethyleneimine (PEI) solution. The charged GO was spin-coated on the polydimethylsiloxane (PDMS) stamp to achieve maskless patterning by a transfer printing method. The feature sizes of the printed GO patterns obtained range from 20 to 90 μm and the transfer-printed area reaches 2 cm* 2 cm. We also discuss the mechanisms of the transfer process, which are dependent on the different strengths of nonspecific adhesion at the interface between the PDMS-GO sheets and substrate-GO sheets, as well as the electrostatic interaction between charged functional groups on GO and PEI molecules. Raman spectra and mapping not only show the result of area-selective patterning, but also show the continuity of the GO patterns. Finally, we use this method to fabricate GO patterns on glass substrate and transform these GO patterns to reduced graphene oxide through thermal treatment.