Edri Eran, Regev Oren
Department of Chemical Engineering, Ben-Gurion University of the Negev, 84105 Beer Sheva, Israel.
Langmuir. 2009 Sep 15;25(18):10459-65. doi: 10.1021/la901386y.
Bundles of nanotubes have been exfoliated in solution by handful of dispersants, such as surfactants, polymers, or proteins, for efficient use in various applications. Common procedures in carbon nanotube exfoliation and dispersion are sonication followed by centrifugation. The dispersion dynamics of single-walled carbon nanotubes (SWNT) by protein were studied by UV-vis spectroscopy (enhanced with chemometric analysis) and low-temperature transmission electron microscopy (cryo-TEM). We studied the effect of both pH and BSA-to-SWNT ratio on SWNT exfoliation dynamics and recovery. We found that, indeed, BSA properties (i.e., electric charge and conformation) affect the exfoliation dynamics in a similar manner as it affects the SWNT recoveries: bulkier protein conformation-->faster exfoliation-->higher SWNT recoveries. Higher BSA-to-SWNT ratio results in lower recoveries and slower dynamics, suggesting that entropic consideration may take part in the exfoliation-stabilization process of SWNT.
通过少量分散剂（如表面活性剂、聚合物或蛋白质），纳米管束已在溶液中剥离，以便在各种应用中高效使用。碳纳米管剥离和分散的常见步骤是超声处理，然后离心。通过紫外可见光谱（用化学计量分析增强）和低温透射电子显微镜（低温透射电镜）研究了蛋白质对单壁碳纳米管（SWNT）的分散动力学。我们研究了pH值和牛血清白蛋白与SWNT比例对SWNT剥离动力学和回收率的影响。我们发现，实际上，牛血清白蛋白的性质（即电荷和构象）对剥离动力学的影响方式与其对SWNT回收率的影响方式相似：蛋白质构象越庞大→剥离越快→SWNT回收率越高。牛血清白蛋白与SWNT的比例越高，回收率越低，动力学越慢，这表明熵的因素可能参与了SWNT的剥离-稳定过程。
