Sulfonated Poly(ether ketone) Grafted Multi-Walled Carbon Nanotubes

Abstract

We report water-soluble multi-walled carbon nanotubes (MWCNT), to which sulfonated hyperbranched poly(ether-ketone) (SHPEK) is grafted. To endorse sufficient water affinity to MWCNT, dendritic hyperbranched poly(ether-ketone) (HPEK) was first covalently grafted to the surface of MWCNT via Friedel-Crafts acylation reaction. The resultant HPEK grafted MWCNT (HPEK-g-MWCNT) was subsequently sulfonated in chlorosulfonic acid to produce SHPEK-g-MWCNT, which is soluble well in water showing Zeta potential value of -57.8 mV (good stability). The SHPEK-g-MWCNT paper prepared from a simple filtration of aqueous dispersion has sheet resistance as low as 63 Ω/sq and high electrocatalytic activity for oxygen reduction reaction (ORR). Thus, the new design and synthetic methodologies suggest that water-dispersible MWCNT, which is a new class of high performance cathode material for ORR.