Room Temperature‐Sintering Conductive Ink Fabricated from Oleic‐Modified Graphene for the Flexible Electronic Devices

Abstract

Graphene, a novel 2D nanomaterial, has been intensively studied and utilized in many fields of applications. Graphenebased conductive ink has attracted many scientific researchers due to its flexibility, durability, and, most importantly, high electrical conductivity. However, the low dispensability and high curing temperature have hindered the use of graphene ink in many practical applications. In this work, graphene nanoplatelets (GNPs) were modified with oleic acid to improve dispensability. Then, the modified GNPs were employed as a major component in the conductive ink's formulation. The effects of the oleic acid, binder, and GNPs contents on the conductivity of the prepared ink were studied. The results showed that at the ink's formulation of 0.75 % binder and 6 % GNPs (modified with 2.5 % oleic acid), the lowest resistance with the value of 22 Ω.cm and sheet resistance of 7.56 Ω cm 2 was obtained. Remarkably, the high conductivity of the modified conductive ink on the substrate could also be observed after curing at room temperature, which is advantageous for practical application. The viscosity of the resultant conductive ink could also be adjusted by changing the amount of solvent in the ink's formulation for application of the ink in the pen, painting, or inkjet printing.