Functional Janus structured liquids and aerogels

• Published in: Nature communications Vol. 14; no. 1; p. 7811
• Main Authors: Ghaffarkhah, Ahmadreza, Hashemi, Seyyed Alireza, Ahmadijokani, Farhad, Goodarzi, Milad, Riazi, Hossein, Mhatre, Sameer E., Zaremba, Orysia, Rojas, Orlando J., Soroush, Masoud, Russell, Thomas P., Wuttke, Stefan, Kamkar, Milad, Arjmand, Mohammad
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 28.11.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 147/135; 147/28; 639/166/898; 639/301/1005/190; Absorption; Aerogels; Anisotropy; chemical engineering; Electromagnetic interference; Electromagnetic shielding; Fabrication; fluidics; Functional materials; Graphene; Human motion; Humanities and Social Sciences; Jamming; Liquid-liquid interfaces; Liquids; multidisciplinary; Nanoparticles; Porosity; Science; Science (multidisciplinary); Streaming
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-43319-7

Janus structures have unique properties due to their distinct functionalities on opposing faces, but have yet to be realized with flowing liquids. We demonstrate such Janus liquids with a customizable distribution of nanoparticles (NPs) throughout their structures by joining two aqueous streams of NP dispersions in an apolar liquid. Using this anisotropic integration platform, different magnetic, conductive, or non-responsive NPs can be spatially confined to opposite sides of the original interface using magnetic graphene oxide (mGO)/GO, Ti 3 C 2 T x /GO, or GO suspensions. The resultant Janus liquids can be used as templates for versatile, responsive, and mechanically robust aerogels suitable for piezoresistive sensing, human motion monitoring, and electromagnetic interference (EMI) shielding with a tuned absorption mechanism. The EMI shields outperform their current counterparts in terms of wave absorption, i.e., SE T  ≈ 51 dB, SE R  ≈ 0.4 dB, and A = 0.91, due to their high porosity ranging from micro- to macro-scales along with non-interfering magnetic and conductive networks imparted by the Janus architecture. A combination of functional nanoparticles and liquid streaming can be used to generate structures for the fabrication of soft functional materials. In this study, authors demonstrate the creation of Janus-structured liquids with anisotropic and programmable distributions of nanoparticles by utilizing interfacial assembly and jamming of nanoparticles at the liquid-liquid interface.