Investigation on Water Dispersibility of Single-walled Carbon Nanotubes Functionalized with Macromolecular Chitosan

OBJECTIVE To improve the poor water solubility of single-walled carbon nanotubes(SWNTs) by using chitosan(CHI). METHODS Carboxyl SWNTs were obtained by mixed acid methods(sulfuric acid and nitric acid 3∶1). CHI modified SWNTs(CHI/SWNTs) were prepared with ice bath ultrasonic dispersion method and characerized by UV, FT-IR and DSC. The dispersibility of CHI/SWNTs in water, PBS(pH 7.4) and acetic acid-sodium acetate buffer(pH 4.0) was determined with constant temperature oscillation methods. RESULTS The maximum dispersion concentration of CHI/SWNTs in water, PBS (pH 7.4) and acetic acid-sodium acetate buffer (pH 4.0) were 1.99, 2.04 and 1.76 mg·mL^-1, respectively, much higher than SWNTs. CONCLUSION Chitosan can significantly improve the water dispersibility of SWNTs.