A high quality graphene paper has been fabricated using drop-casting of a custom developed stable ink mixture. The graphene/ethyl cellulose mixture can produce graphene paper coating on Kapton substrate at fairly large scales by finely adjusting the viscosity of the ethyl cellulose solvent blend. It was possible to produce a morphologically intact 300 nm-thick stacked structures of high purity graphene platelets after annealing at 300 °C, as characterized by SEM, Raman Spectroscopy and AFM. The electrical resistivity of a large batch of samples was measured and the results thoroughly evaluated, using a design of experiments approach. The resistivity values achieved were found to be lower or comparable to the best results reported in the literature. As expected, resistivity is inherently related to the concentration of the as-prepared ink and subsequent annealing conditions. However, prolonged annealing time can deteriorate mechanical properties as determined by cyclic bending and shear tests. It is anticipated that the present graphene paper has potential use in flexible electronics applications since the lowest resistivity and structure achieved were generally unaffected by the range of mechanical loadings studied.
This is a preview of subscription content, log in to check access.
The main author, K. Karimi, gratefully acknowledges the financial support from the University of Waterloo. This work would not have been possible without the use of equipment and assistance of the technical staff of the Multiscale Additive Manufacturing Lab (MSAM) and the Composites and Adhesives Lab in the Department of Mechanical and Mechatronics Engineering.