Variance Spectroscopy Studies of Single-Wall Carbon Nanotube Aggregation
Variance Spectroscopy Studies of Single-Wall Carbon Nanotube Aggregation
复制标题
DOI：
10.1021/acs.jpcc.8b07173
复制
发表时间：
2018-10
期刊：
影响因子：
--
通讯作者：
Stephen R Sanchez;S. Bachilo;R. Weisman
中科院分区：
文献类型：
--
作者：
Stephen R Sanchez;S. Bachilo;R. Weisman
利用结构分辨荧光光谱和方差光谱研究了单壁碳纳米管在表面活性剂水溶液中的早期聚集行为。在加入NaCl使分散的样品不稳定之后，方差数据显示发射颗粒的浓度强烈降低，而荧光光谱仅显示出适度的变化。这表明松散的聚集体的形成，其中单个纳米管之间的电子接触太有限而不能干扰它们的发射。方差数据表明，初始形成率的同质聚集体（集群相同的（n，m）物种）与NaCl浓度超线性增加。协方差分析给出了互补的结构分辨发射杂聚集体的数据。对于这两种类型的集群，它被发现的初始聚集速率与物种粒子浓度，但没有显示出明确的依赖于纳米管结构。方差谱法可以灵敏地检测和分析各种噪声。
Early stages of single-wall carbon nanotube aggregation in aqueous surfactant suspension have been investigated through combined structure-resolved fluorescence and variance spectroscopies. Following the addition of NaCl to destabilize dispersed samples, variance data revealed strong decreases in the concentrations of emitting particles, while fluorescence spectra showed only modest changes. This indicates the formation of loose aggregates in which electronic contact between individual nanotubes is too limited to perturb their emission. Variance data showed that the initial formation rates of homoaggregates (clusters of the same (n,m) species) increase superlinearly with NaCl concentration. Co-variance analysis gave complementary structure-resolved data on emissive heteroaggregates. For both types of clusters, it is found that the initial aggregation rates correlate with species particle concentrations, but show no clear dependence on nanotube structure. Variance spectroscopy can sensitively detect and ch...