Nonaqueous Interfacial Polymerization-Derived Polyphosphazene Films for Sieving or Blocking Hydrogen Gas

Farzaneh Radmanesh; Alberto Tena; Ernst J R Sudhölter; Mark A Hempenius; Nieck E Benes

doi:10.1021/acsapm.2c02022

Nonaqueous Interfacial Polymerization-Derived Polyphosphazene Films for Sieving or Blocking Hydrogen Gas

ACS Appl Polym Mater. 2023 Feb 9;5(3):1955-1964. doi: 10.1021/acsapm.2c02022. eCollection 2023 Mar 10.

Authors

Farzaneh Radmanesh¹, Alberto Tena^{2

3}, Ernst J R Sudhölter^{1

4}, Mark A Hempenius⁵, Nieck E Benes¹

Affiliations

¹ Membrane Science and Technology Cluster, Faculty of Science and Technology, MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
² The European Membrane Institute Twente, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
³ Surfaces and Porous Materials (SMAP), Associated Research Unit to CSIC, UVainnova Bldg, Po de Belén 11 and Institute of Sustainable Processes (ISP), Dr. Mergelina S/n, University of Valladolid, 47071 Valladolid, Spain.
⁴ Organic Materials & Interfaces, Department of Chemical Engineering, Faculty of Applied Sciences, Delft University of Technology, 2629 HZ Delft, The Netherlands.
⁵ Sustainable Polymer Chemistry, Faculty of Science and Technology, MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500, AE Enschede, The Netherlands.

Abstract

A series of cyclomatrix polyphosphazene films have been prepared by nonaqueous interfacial polymerization (IP) of small aromatic hydroxyl compounds in a potassium hydroxide dimethylsulfoxide solution and hexachlorocyclotriphosphazene in cyclohexane on top of ceramic supports. Via the amount of dissolved potassium hydroxide, the extent of deprotonation of the aromatic hydroxyl compounds can be changed, in turn affecting the molecular structure and permselective properties of the thin polymer networks ranging from hydrogen/oxygen barriers to membranes with persisting hydrogen permselectivities at high temperatures. Barrier films are obtained with a high potassium hydroxide concentration, revealing permeabilities as low as 9.4 × 10^-17 cm³ cm cm^-2 s^-1 Pa^-1 for hydrogen and 1.1 × 10^-16 cm³ cm cm^-2 s^-1 Pa^-1 for oxygen. For films obtained with a lower concentration of potassium hydroxide, single gas permeation experiments reveal a molecular sieving behavior, with a hydrogen permeance of around 10^-8 mol m^-2 s^-1 Pa^-1 and permselectivities of H₂/N₂ (52.8), H₂/CH₄ (100), and H₂/CO₂ (10.1) at 200 °C.