Declined ionic flux through the nano-pores of vertically aligned carbon nanotubes filled with PNIPAm hydrogel

We demonstrate a novel nano-porous membrane of 10 nm diameter multiwall carbon nanotubes (MWCNTs) filled with thermally sensitive poly(N-isopropylacrylamide) (PNIPAm) hydrogel. High-resolution transmission electron microscopy (HRTEM), micro FT-IR spectroscopy and confocal laser scanning fluorescence microscopy are used to confirm that the MWCNTs are filled with the hydrogel. An improvement in the hydrophilicity of the gel-filled nano-channels is expected to promote the migration of aqueous solutions and the transportation of water. Meanwhile a decrease in ion flux is observed after the nano-pores of MWCNTs are filled with the hydrogel. This new hydrogel filled-CNT material shows potential for nano-chromatography, water purification and use as intelligent ionic channels.