Single step synthesis of Janus nano-composite membranes by atmospheric aerosol plasma polymerization for solvents separation

Xiao Chen; Chiara Lo Porto; Zhiqiang Chen; Andrea Merenda; François-Marie Allioux; Riccardo d'Agostino; Kevin Magniez; Xiujuan J Dai; Fabio Palumbo; Ludovic F Dumée

doi:10.1016/j.scitotenv.2018.06.343

Single step synthesis of Janus nano-composite membranes by atmospheric aerosol plasma polymerization for solvents separation

Sci Total Environ. 2018 Dec 15:645:22-33. doi: 10.1016/j.scitotenv.2018.06.343. Epub 2018 Jul 14.

Affiliations

¹ Deakin University, Geelong, Institute for Frontier Materials, Waurn Ponds 3216, VIC, Australia. Electronic address: vwq@deakin.edu.au.
² Department of Chemistry, University of Bari, via E. Orabona 4, 70126 Bari, Italy.
³ Deakin University, Geelong, Institute for Frontier Materials, Waurn Ponds 3216, VIC, Australia.
⁴ Institute of Nanotechnology, CNR, via E. Orabona 4, 70126 Bari, Italy.
⁵ Deakin University, Geelong, Institute for Frontier Materials, Waurn Ponds 3216, VIC, Australia. Electronic address: ludovic.dumee@deakin.edu.au.

PMID: 30015115
DOI: 10.1016/j.scitotenv.2018.06.343

Abstract

Solvent permeation across membranes is limited due to physical resistance to diffusion from the selective layer within the membrane and to plasticizing effects generated by the solvent molecules onto the polymeric macromolecular matrix. Nano-composite thin film membranes provide promising routes to generate controlled microstructural separation materials with higher selectivities and permeabilities. Here, the fabrication of nano-composite based on octamethyl-polyhedral oligomeric silsesquioxane - hexamethyldisiloxane thin film membranes is demonstrated by aerosol assisted atmospheric plasma deposition onto pre-formed nano-porous membrane supports for the first time. Stable, atomically smooth and continuous solid films with controllable thickness down to 50 nm were achieved. The deposition process allowed for the control of the wettability of the surfaces to water and organic solvents, leading to the generation of hydrophobic but alcohol-philic surfaces. The liquid entry pressure of the films to water was found to be 8 bar from plasma polymerization as oppose to 3 bar for the bare nano-porous support only. In addition, the ideal separation selectivity for ethanol to water, up to 6.5, highlight the impact of both the surface energy and level of cross-linking of the hexamethyldisiloxane nanostructures on the diffusion mechanisms. This new atmospheric plasma deposition strategy opens-up cost-effective and environmentally friendly routes for the design of the smart Janus membrane with customizable properties and performance.

Keywords: Aerosol assisted atmospheric plasma deposition; Ethanol-water separation; Janus membrane; Nano-composite thin films; Surface energy control.