Surfactant Chemistry and Polymer Choice Affect Single-Wall Carbon Nanotube Extraction Conditions in Aqueous Two-Polymer Phase Extraction
Christopher Sims, Jeffrey Fagan
Quantitative determination of the effects of surfactant chemistry and polymer molecular mass choices on the concentration conditions necessary to yield extraction of specific single-wall carbon nanotube (SWNCT) species in an aqueous two-polymer phase extraction (ATPE) separation are reported. In particular, the effects of polyethylene glycol (PEG) molecular mass, surfactant ratios, and systematic structural variations of alkyl surfactants and bile salt were investigated using a recently reported fluorescence emission monitoring method. Alkyl surfactant tail length was observed to strongly affect the amount of surfactant necessary to cause PEG-phase extraction of nanotube species in ATPE extraction, while variation in the anionic sulfate/sulfonate head group chemistry has a much lower impact on the concentration of alkyl surfactant necessary for extraction. Substitution of different bile salts results in different surfactant packing structures around the SWCNTs, with the substitution also greatly affecting the alkyl surfactant concentrations required for (n,m) extraction. Finally, distinct SDS:DOC surfactant ratios were found to extract specific (n,m) SWCNTs, supporting the hypothesized competitive adsorption mechanism model of SWCNT sorting. Altogether, these results provide valuable insights into the underlying mechanisms behind ATPE-based SWCNT separations, towards further development and optimization of the ATPE method for SWCNT chirality and handedness sorting.
and Fagan, J.
Surfactant Chemistry and Polymer Choice Affect Single-Wall Carbon Nanotube Extraction Conditions in Aqueous Two-Polymer Phase Extraction, Carbon, [online], https://doi.org/10.1016/j.carbon.2022.01.062, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933343
(Accessed October 3, 2023)