posted on 2024-02-23, 15:07authored byChunyang Liu, Yanrong Cheng, Delan Ge, Ju Xie, Xia Guo
Aqueous two-phase systems (ATPS)
are considered a new
type of green
separation system, but their low selectivity to target molecules limits
their practical application. In this study, we used surfactant@MWCNT
as an adjuvant to improve the selectivity of PEG/(NH4)2SO4 ATPS. The surfactants used include Triton X-100
(TX-100), Tween 80, sodium dodecyl sulfate (SDS), sodium dodecyl benzenesulfonate
(SDBS), and bis(2-ethylhexyl)sulfosuccinate sodium salt (AOT). Nine
aromatic compounds, including syringic acid, vanillin, tryptophan,
phenylalanine, tyrosine, mandelic acid, theophylline, theobromine,
and cephalexin, were selected as model extracts. The results showed
that the use of the surfactant@MWCNT composite as an adjuvant significantly
improved the selectivity of the ATPS toward syringic acid among the
nine extracts. Moreover, the selectivity of the ATPS for syringic
acid with the TX-100/MWCNT composite as the adjuvant is better than
that with the Tween 80/MWCNT composite as the adjuvant, followed by
that with the anionic surfactant/MWCNT composite as the adjuvant.
The enhanced selectivity of ATPS by the surfactant/MWCNT composite
is ascribed to the spatial effect and the electrostatic and hydrophobic
interactions between the extract and the surfactant adsorbed on the
MWCNT.