pH effects on BSA-dispersed carbon nanotubes studied by spectroscopy-enhanced composition evaluation techniques.
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.
Edri
Eran
E
Department of Chemical Engineering, Ben-Gurion University of the Negev, 84105 Beer Sheva, Israel.
Regev
Oren
O
D000818:Animals; D002138:Calibration; D002417:Cattle; D006863:Hydrogen-Ion Concentration; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011487:Protein Conformation; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
D037742:Nanotubes, Carbon; D012710:Serum Albumin, Bovine