Poly(2,6-dimethyl-1,4-phenylene oxide) hybrid membranes filled with magnetically aligned iron-encapsulated carbon nanotubes (Fe@MWCNTs) for enhanced air separation

Various inorganic-organic hybrid membranes based on regular and modified poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) matrix and iron-encapsulated multi-wall carbon nanotubes (Fe@MWCNTs) were designed and prepared for air separation. Addition of Fe@MWCNTs into the PPO matrix has changed gas transport parameters (D, P, S and α) through the hybrid membranes. Indeed, we have demonstrated that application of magnetic field during the stage of nanotube-polymer membrane preparation has enhanced alignment of the nanotube filler in the polymer matrix and improved separation performance of the membranes. Additionally, hydroxylation of Fe@MWCNTs and sulfonation of PPO matrix – as applied to enhance the nanotube-polymer interphase via hydrogen bonding – also accompanied by external magnetic field have allowed to obtain membranes with higher permeability, diffusivity and permselectivity. Mechanical properties, such as tensile strength (Rm) and Young's modulus under tensile (E), as well as magnetic parameters of the membranes were further found as improved by the increase of Fe@MWCNT content and the presence of magnetic field. [Display omitted] •A new type of magnetic-cast Fe@MWCNT/PPO hybrid membranes for air separation•Fe@MWCNTs vertical alignment and better dispersion in magnetic-cast hybrid membranes•Higher permeability and selectivity of modified magnetic-cast hybrid membranes•Improvement of the mechanical and magnetic hybrid membrane's parameters