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Abstract：
A significant advance in rate and precision of identifying the co-surfactant concentrations leading to differential extraction of specific single-wall carbon nanotube (SWCNT) species in aqueous two-polymer phase extraction experiments is reported. These gains are achieved through continuous titration of co-surfactant and other solution components during automated fluorescence measurements on SWCNT dispersions. The resulting fluorescence versus concentration curves display intensity and wavelength shift transitions traceable to the nature of the adsorbed surfactant layer on specific SWCNT structures at the (n,m) species and enantiomer level at high resolution. The increased precision and speed of the titration method resolve previously invisible complexity in the SWCNT fluorescence during the transition from one surfactant dominating the SWCNT interface to the other, offering insight into the fine details of the competitive exchange process. For the first time, we additionally demonstrate that the competitive process of the surfactant switch is direction independent (reversible) and hysteresis-free; the latter data effectively specifies an upper bound for the time scale of the exchange process. Titration curves are compared to literature results and initial advanced parameter variation is conducted for previously unreasonable to investigate solution conditions.
摘要：
据报道，在鉴定助表面活性剂浓度的速率和精度方面取得了显着进步，导致在水性双聚合物相萃取实验中特定的单壁碳纳米管（SWCNT）物种的差异萃取。这些增益通过在SWCNT分散体的自动荧光测量期间连续滴定助表面活性剂和其他溶液组分来实现。所得的荧光与浓度曲线显示强度和波长偏移跃迁可追踪到特定SWCNT结构上吸附的表面活性剂层的性质（n，m）高分辨率的物种和对映异构体水平。滴定法提高的精度和速度解决了以前不可见的复杂性在SWCNT荧光从一个表面活性剂占主导地位的SWCNT界面过渡到另一个。深入了解竞争性交换过程的细节。第一次,我们还证明了表面活性剂转换的竞争过程是方向独立的（可逆的）和无滞后的；后者的数据有效地指定了交换过程时间尺度的上限。将滴定曲线与文献结果进行比较，并对先前不合理的溶液条件进行初始高级参数变化。
