Z Ryan Tian
Institute of Nanoscience / Engineering, USA
Title: Crosslinking graphene oxide flakes into nonflammable membrane for safe mass-production
Biography
Biography: Z Ryan Tian
Abstract
Graphene oxide (GO), a flake-like intermediate for making graphene from graphite, was proven by our lab and others’ to possess a fire hazard that can jeopardize the graphene large-scale production and wide applications. To solve this longstanding built-in problem, we have developed a simple, facile and scalable method for polymerizing the irregularly shaped/sized graphene oxide flakes with multivalent metal cations, such as Al3+, into a freestanding, mechanically strong, and paper-like flexible inflammable membrane in the form of a GO-oligomer. Thus-formed membrane that’s transparent to the naked eyes, about 10 um in thickness, resists in-air burning on an open flame (at which non-crosslinked graphene oxide was burnt out within ∼5 seconds), and resist hydrolysis in water over long time (during which non-crosslinked graphene oxide membrane quickly decomposes). Characterization data from SEM, HRTEM, XRD, microRaman, TGA/DSC, FTIR, and flame tests concluded that the multivalent cations effectively cross-linked the GO flakes, which in turn confirmed a strategy for polymerizing sheet-like nanomaterials in general.
With the much improved on-flame and in-water stabilities, the membrane can enable e.g. roll-to-roll printing of high-temperature fuel cell membrane, battery membrane separators and electrodes, wearable electronics, flexible electronics, flexible thin-foil solar-cells, spray-able device packaging, sensors, etc. Other multivalent cations of transition metals and rare earth metals can likewise produce the new polymers with widely tunable electrical, magnetic and optical properties that ordinary graphene cannot possess.