title: Ultraporous superhydrophobic gas-permeable nano-layers by scalable solvent-free one-step self-assembly.
abstract: Superhydrophobic materials with excellent humidity tolerance, high porosity and light transmittance are being investigated for numerous applications including moisture-sensitive catalysts and perovskite solar cells. Here, we report the one-step solvent-free synthesis of ultraporous superhydrophobic nano-layers by the on-the-fly functionalization of nanoparticle aerosols. Short exposure of surfaces to hot Mn3O4, ZnO and TiO2 aerosols results in ultraporous nanoparticle networks with repulsive dewetting state approaching ideal Cassie-Baxter superhydrophobicity. In addition to showcasing sliding angles of ca. 0° and very low contact angle hysteresis of 3° ± 2°, these optimal nano-layers have up to 98% porosity and pore size of several micrometres, a key feature to enable efficient penetration of gases to the substrate surface. The stability of this ultraporous superhydrophobic morphology is demonstrated by rapidly applying Moses effect-functionality to substrates that parts water up to 5 mm high. This scalable synthesis method offers a flexible and rapid approach for the production of numerous moisture-resistant devices including gas sensors, catalysts and perovskite solar cells.
authors.affiliation: Nanotechnology Research Laboratory, Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, 2001 Australia. antonio.tricoli@anu.edu.au.
authors.forename: Guanyu
authors.initials: G
authors.lastname: Liu
authors.affiliation: Nanotechnology Research Laboratory, Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, 2001 Australia. antonio.tricoli@anu.edu.au.
authors.forename: William S Y
authors.initials: WS
authors.lastname: Wong
authors.affiliation: Nanotechnology Research Laboratory, Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, 2001 Australia. antonio.tricoli@anu.edu.au.
authors.forename: Noushin
authors.initials: N
authors.lastname: Nasiri
authors.affiliation: Nanotechnology Research Laboratory, Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, 2001 Australia. antonio.tricoli@anu.edu.au.
authors.forename: Antonio
authors.initials: A
authors.lastname: Tricoli