Structured Ultra-Flyweight Aerogels by Interfacial Complexation: Self-Assembly Enabling Multiscale Designs

The rapid co-assembly of graphene oxide (GO) nanosheets and a surfactant at the oil/water (O/W) interface is harnessed to develop a new class of soft materials comprising continuous, multilayer, interpenetrated, and tubular structures. The process uses a microfluidic approach that enables interfacial complexation of two-phase systems, herein, termed as liquid streaming (LS). LS is demonstrated as a general method to design multifunctional soft materials of specific hierarchical order and morphology, conveniently controlled by the nature of the oil phase and extrusion's injection pressure, print-head speed, and nozzle diameter. The as-obtained LS systems can be readily converted into ultra-flyweight aerogels displaying worm-like morphologies with multiscale porosities (micro- and macro-scaled). The presence of reduced GO nanosheets in such large surface area systems renders materials with outstanding mechanical compressibility and tailorable electrical activity. This platform for engineering soft materials and solid constructs opens up new horizons toward advanced functionality and tunability, as demonstrated here for ultralight printed conductive circuits and electromagnetic interference shields.

Automated summary

A new class of soft materials with continuous, multilayer, interpenetrated, and tubular structures has been developed through the rapid co-assembly of graphene oxide nanosheets and a surfactant at the oil/water interface. This was achieved using a microfluidic approach called liquid streaming (LS) which allows for the design of multifunctional soft materials with specific hierarchical order and morphology. The resulting LS systems can be converted into ultra-flyweight aerogels with worm-like morphologies and excellent mechanical compressibility and tailorable electrical activity.