Main content area

Filament printing of graphene-based inks into self-supported 3D architectures

Moyano, J.J., Gómez-Gómez, A., Pérez-Coll, D., Belmonte, M., Miranzo, P., Osendi, M.I.
Carbon 2019 v.151 pp. 94-102
electrical conductivity, freeze drying, graphene, graphene oxide, heat, hydrogels, hydrophilicity, hydrophobicity, modulus of elasticity, nanocomposites, surfactants
The arrangement of 2D graphene-type structures into strong and self-supported architectures by filament printing depends critically on the ink characteristics. Printable inks are normally achieved by controlling the electro-steric interactions in the particle dispersion by different means. This research shows that is possible to use just a single surfactant for graphene-type inks, such as graphene oxide (GO), graphene nanoplatelets (GNP) and their mixtures, to achieve characteristics of gelled inks, in other words, shear-thinning behavior and a high elastic modulus at rest. The surfactant is a commercial hydrogel former of the poloxamer family that contains both hydrophilic and hydrophobic blocks. These inks do not require lyophilization or supercritical drying processes, accordingly the method is simple, scalable and produces lightweight 3D printed structures that exhibit high strength and prominent electrical conductivity after heat treating at 1200 °C. Furthermore, it makes possible to adjust the proportion of GO and GNP in the ink to tailor the properties of the structure according to the pursued application.