Interfacial Assembly of Graphene Oxide: From Super Elastic Interfaces to Liquid‐in‐Liquid Printing
Milad Kamkar, Elnaz Erfanian, Parisa Bazazi, Ahmadreza Ghaffarkhah, Farbod Sharif, Ganhua Xie, Aadithya Kannan, Mohammad Arjmand, S. Hossein Hejazi, Thomas P. Russell, Gerald G. Fuller, Uttandaraman Sundararaj
Abstract
Abstract Tailoring the oil/water (O/W) interface is a prerequisite for structuring these two immiscible liquids into prescribed architectures, i.e., liquid‐in‐liquid printing, which is an emerging area in material science. Here, assemblies of graphene oxide (GO) at O/W and air/W interfaces are characterized using a wide range of interfacial rheological techniques. It is shown that the GO nanosheets assemble at the interface, even at extremely low concentrations as low as 0.04 vol%, significantly increasing the elasticity at O/W or air/W interfaces. This is attributed to the combined hydrophobic and hydrophilic nature of GO. Interfacial elastic modulus of ≈1800 mN m −1 is achieved, making GO assemblies exceptional candidates for applications where stabilization of the O/W interface is indispensable. Herein, the super elastic character of the O/W interface with GO assemblies is capitalized for all‐liquid 2D printing in a low viscous oil, underscoring the utility of these all‐liquid systems for electronics, fluidic devices, and controlled release systems.