The synthesis of polyacrylonitrile/carbon nanotube microspheres by aqueous deposition polymerization under ultrasonication

Polyacrylonitrile (PAN)/carbon nanotube (CNT) microspheres with diameters approximately 300–500 nm were synthesized by aqueous deposition polymerization under ultrasonication. A new absorption band appeared in the Fourier transform infrared spectrum of the PAN/CNT microspheres indicated that the functionalized CNTs interacted chemically with the itaconic acid on the PAN macromolecules. The results from the UV–vis and Raman spectra suggested that the functionalized CNTs and PAN macromolecules had interfacial interaction. The peak shift for the radical breathing modes in Raman spectra indicated that the functionalized CNTs were debundled by the PAN macromolecules during polymerization under ultrasonication. X-ray diffraction data showed that the PAN/CNT microspheres had higher degree of crystallization and larger crystal size than those of PAN, which was confirmed by the second exothermic peak of the differential scanning calorimeter scan in a nitrogen atmosphere. Thermogravimetric analysis showed that the addition of the functionalized CNTs improved the thermal stability of PAN.