Effect of natural surfactant on the performance of reduced graphene oxide conductive ink

Conductive ink with stable dispersion and excellent printing properties can be produced using graphene-based nanomaterials and suitable solvents for flexible printed electronics applications. Eco-friendly water-based inks can be used as an alternative to organic solvents-based inks to minimize environmental impacts. Graphene oxide (GO) nanofillers can form stable aqueous dispersions and can be produced in bulk quantities using chemical exfoliation methods. Hence GO nanofillers can be used as a filler to produce water-based conductive ink for printed electronics applications. However, the higher surface tension and lower stability are major drawbacks which limit its printing properties. Natural surfactants can minimize these issues to ensure smooth printing with a higher shelf life as compared to harmful synthetic surfactants. This study aimed to investigate the role of natural-based surfactants such as gum arabic, cellulose nanocrystals and alkali lignin in producing stable and high performing water-based GO ink. The prepared ink samples were characterized for their wetting properties, printability, and storage time. The ink was also investigated for structural, functional groups, and stability. The printed patterns were investigated for morphological and electrical properties. The results from study indicate that the GO with alkali lignin surfactant gives long-term stability and better printing properties compared to other samples. The printed pattern after thermal reduction was found to have a conductivity of 833 S/m, which was reduced by only 2.6% after 100 bending cycles, whereas the electrical conductivity was reduced by only 0.6% after 10 rolling cycles indicating a great potential to be used in flexible electronic devices.