Edri Eran, Regev Oren
Department of Chemical Engineering, Ben-Gurion University of the Negev, 84105 Beer Sheva, Israel.
Anal Chem. 2008 Jun 1;80(11):4049-54. doi: 10.1021/ac800124x. Epub 2008 May 7.
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.
通过水溶性分散剂（如表面活性剂、聚合物或蛋白质）对碳纳米管（CNT）进行分散和剥离，是碳纳米管应用于复合材料、生化及生物医学领域的关键一步。分散后，溶液相分离为上清液中的分散纳米管以及沉淀相，沉淀相中包含碳质杂质，但也有纳米管和分散剂。然而，目前尚无简单而准确的工具来测量各成分的浓度。在大多数研究中，碳纳米管悬浮液之间的比较基于肉眼观察或在单一波长下对无特征光谱的紫外可见测量。此类测量很复杂，因为纳米管和大多数分散剂在整个紫外可见光谱范围内均有吸收，且它们的信号会发生重叠。在本文中，我们采用化学计量技术，根据水溶液的完整紫外可见光谱来评估pH值对分散剂（蛋白质 - 牛血清白蛋白，BSA）和单壁纳米管（SWNT）浓度的影响。我们发现蛋白质的构象与其分散效率之间存在很强的相关性。
