title: CO2 - and O2 -sensitive fluorophenyl end-capped poly(ethylene glycol).
abstract: Pentafluorophenyl end-capped poly(ethylene glycol) (PF-PEG-PF) aqueous solution shows a lower critical solution temperature (LCST), which is sensitive to the type of gases dissolved in the solution. LCST increases from 24.5 to 26 °C when dissolved carbon dioxide is replaced by oxygen. The transparent-to-turbid transition is reversibly observed when the dissolved carbon dioxide in the PF-PEG-PF aqueous solution is exchanged with oxygen, and vice versa, at 24.5 °C. (19) F NMR and (1) H NMR spectra of the PF-PEG-PF in D2 O suggest that 1) dehydration of PEG is the main reason of developing LCST of the PF-PEG-PF aqueous solution, 2) minute differences in the intermolecular interactions, as demonstrated by changes in the chemical shift of the PF-PEG-PF peaks, induce such a difference in LCST. This paper provides a new insight in designing a stimuli-responsive polymer in that fine tuning of a phase transition can be controlled by the type of dissolved gas.
authors.affiliation: Department of Chemistry and Nano Science, Ewha Global Top 5 Research Program, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul, 120-750, Korea.
authors.forename: Jung Yoon
authors.initials: JY
authors.lastname: Choi
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Hyo Jung
authors.initials: HJ
authors.lastname: Moon
authors.forename: Min Hee
authors.initials: MH
authors.lastname: Park
authors.forename: Byeongmoon
authors.initials: B
authors.lastname: Jeong
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010100:Oxygen / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*
chemical_list: D002245:Carbon Dioxide; D011092:Polyethylene Glycols; D010100:Oxygen
keywords: fluoropolymer; oxygen-sensitive; stimuli-sensitive