pH Effects On BSA-Dispersed Carbon Nanotubes Studied by Spectroscopy-Enhanced Composition Evaluation Techniques Academic Article uri icon


  • Dispersion and exfoliation of carbon nanotubes (CNT) by water soluble dispersants such as surfactant, polymer or protein is a key step toward the application of carbon nanotubes in composite materials, biochemical and biomedical applications. Upon dispersion, the solution phase separates into dispersed nanotubes in the supernatant and a precipitate phase including carbonaceous impurities but also nanotubes and dispersants. Yet, simple but accurate tools for measuring the concentrations of the constituents are not available. In most studies a comparison between CNT suspensions is based on ocular observation or on UV−visible measurement of a featureless spectrum at single wavelength. Such measurements are complex since both nanotubes and most dispersants absorb along the whole UV−visible spectrum and an overlap of their signals occurs. In this paper we employ chemometric techniques to evaluate the pH effect on the concentration of both dispersant (protein−bovine serum albumin, BSA) and single-wall nanotube (SWNT) from a full UV−visible spectrum of aqueous solutions. We find strong correlation between the conformation of the protein and its dispersion efficiency.

publication date

  • June 1, 2008