Improvement of carbon nanotubes dispersion by chitosan salt and its application in silicone rubber

Abstract We have prepared chitosan hydrochloric acid salt and investigated its assistance in improving the dispersion of carbon nanotubes in different solvents and silicone rubber in this study. It was found that the dispersions of carbon nanotubes in some solvents improved to some extent. Long-time stable dispersions were achieved in water and chloroform, even after being placed for 3 months and a following centrifuging (10,000 rpm for 10 min). It was also found that treated carbon nanotubes could be dispersed in the silicone rubber homogeneously based on SEM and XRD analysis. The incorporation of carbon nanotubes enhanced the thermal stability of the silicone rubber. They also significantly improved the mechanical properties of the silicone rubber matrix. From the FTIR spectra, it was believed that chitosan hydrochloric acid salt adsorbed on the surface of the carbon nanotube and then interacted with silicone rubber matrix, resulting in the enhancement of dispersion of carbon nanotubes. From this study, chitosan hydrochloric acid salt was an easy available material which could be used as the treating agent to enhance the dispersion of carbon nanotubes in solvents and polymer matrixes, with improved thermal and mechanical properties in the resulting nanocomposites.