Perfluorinated hybrid membranes modified by metal decorated clay nanotubes

• Published in: Journal of membrane science Vol. 582; pp. 172 - 181
• Main Authors: Petrova, D.A., Filippov, A.N., Kononenko, N.A., Shkirskaya, S.A., Timchenko, M.O., Ivanov, E.V., Vinokurov, V.A., Lvov, Yu.M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-07-2019
• Subjects: Current-voltage curve; Diffusion permeability; Hybrid membrane; Metal-ceramic hybrid halloysite nanotubes; Modelling transport through a membrane; Perfluorinated sulfocationic membrane; Metal-ceramic hybrid halloysite nanotubes; Diffusion permeability; Perfluorinated sulfocationic membrane; Current-voltage curve; Hybrid membrane; Modelling transport through a membrane
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2019.03.084

A number of one-layer perfluorinated cation-exchange membranes modified by halloysite clay nanotubes were prepared using two different solvents: dimethylformamide and isopropanol. The modifier is hybrid Pd, Pt/clay nanotubes doped at 4 wt % into the polymeric matrix. Metal nanoparticles of platinum or palladium were deposited onto the surface of the nanotubes then embedded into membranes providing composite materials which are promising for solid polymer fuel cells.
At the first time the distribution of water, effective pore radius, electrical conductivity, selectivity, diffusion and electroosmotic permeability, contact angles (hydrophilicity/hydrophobicity) were investigated for the presented different types of nanocomposite membranes. It is shown that hybrid cation-exchange membranes demonstrate improved thermal, mechanical and transport properties synergistically combining separation. The optimized halloysite-perfluorinated polymer membranes meet the conditions for electro-transport properties needed for solid electrolytes in separation diaphragms for low-temperature membrane electrolyzers. Introduction of Pt-halloysite into the perfluorinated matrix results in preservation of high selectivity and constant value of the limiting electrodiffusion current density.
Comparing the theoretically calculated parameters, like the limiting current density, selectivity, transport numbers of water to the experimentally measured ones for samples we can conclude that the hybrid membrane with platinum nanoparticles is promising for nanocomposite cation-exchange perfluorinated films both as the separating membrane in fuel cells and other electric devices.
•Perfluorinated membranes doped by core-shell halloysite nanotubes are synthesized.•Hybrid nanocomposites possess high selectivity and improved water uptake.•Link of novel membranes structure vs. transport properties is established.