Functionalization of Multi‐Walled Carbon Nanotubes with Poly(2‐ethyl‐2‐oxazoline)

Abstract

Abstract Multi‐walled carbon nanotubes (MWCNTs) were successfully functionalized with water‐soluble poly(2‐ethyl‐2‐oxazoline) (PEOX) through a polymer wrapping process. Pristine MWCNTs were first treated with nitric acid (HNO 3 ) at 120 °C for 24 hours. The resulting carboxylated MWCNTs were then mixed with 10 wt.% PEOX in ethanol, followed by sonication using a horn‐type sonicator for 30 min and stirring at room temperature for 24 hours. Thereafter, unreacted free polymer was washed out repeatedly by centrifugation with an excess amount of ethanol. Scanning electron microscopy exhibited that the diameter of MWCNTs increased approximately by 10 nm after the functionalization of MWCNT with PEOX. Thermogravimetric analysis showed that approximately 15 wt.% polymer was incorporated in the functionalized MWCNTs. The functionalized MWCNTs gave excellent and stable dispersion in water as well as other organic solvents such as ethanol and DMF.