Aerobijels: Ultralight Carbon Monoliths from Cocontinuous Emulsions

• Published in: Advanced functional materials 2020-02, Vol.30 (6), p.n/a
• Main Authors: Santiago Cordoba, Miguel A., Spendelow, Jacob S., Parra‐Vasquez, Alario Nicholas G., Kuettner, Lindsey A., Welch, Paul M., Hamilton, Christopher E., Oertel, John A., Duque, Juan G., Meierdierks, Eric J., Semelsberger, Troy A., Gordon, John C., Lee, Matthew N.
• Format: Article
• Language: English
• Subjects: Aerogels; bicontinuous materials; bijels; Bulk density; Carbon; carbon electrodes; Charge transport; Electrodes; Electrokinetics; Emulsions; hierarchical materials; Jamming; Materials science; Porosity
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201908383

Bijels are used to develop a new class of ultralight hierarchically porous aerogels exhibiting multimodal porosity across multiple length scales. Through in situ functionalization of a particle‐laden liquid interface wherein binary liquid pairs are kinetically trapped out of equilibrium through interfacial jamming, monolithic and freestanding carbon electrodes are produced with prescribed bulk densities down to ≈2 mg cm−3. Exemplary electrokinetic experiments indicate that the bicontinuity of the pore structure is essential for enhancing transport to and from the active electrode surfaces, demonstrating that these materials possess a superior ability to accumulate and transport charge when compared to analogous systems with restricted pore connectivity and fluid throughput. This approach offers a new synthetic route to bicontinuous and hierarchical aerogel materials with nested multimodal porosities. The flexibility of this scheme can address critical issues related to transport‐limited behaviors that arise in many technological fields, ranging from energy and catalysis research to remediation and sensing applications. A new class of hierarchically porous aerogels is developed using bijels as interfacial scaffolds. These materials exhibit superior electrochemical performance when compared to aerogels formed using gel‐like Pickering emulsions as templates, or to those synthesized using traditional sol–gel techniques. These results introduce the use of bijels for creating new aerogel materials used in thermal management, catalysis, and energy applications.