Gelation mechanism of tetra-armed poly(ethylene glycol) in aprotic ionic liquid containing nonvolatile proton source, protic ionic liquid

The Journal of Physical Chemistry. B
Kei HashimotoMitsuhiro Shibayama

Abstract

We report the gelation mechanism of tetra-armed prepolymer chains in typical aprotic ionic liquid (aIL), i.e., A-B type cross-end coupling reaction of tetra-armed poly(ethylene glycol)s with amine and activated ester terminals (TetraPEG-NH2 and TetraPEG-NHS, respectively) in 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([C2mIm][TFSA]). In the ion gel system, we focused on the pH (or H(+) concentration) dependence of the gelation reaction. We thus applied the protic ionic liquid (pIL), 1-ethylimidazolium TFSA ([C2ImH][TFSA]), as a nonvolatile H(+) source, and added it into the solvent aIL. It was found that the gelation time of TetraPEG ion gel can be successfully controlled from 1 min to 3 h depending on the concentration of pIL (cpIL = 0-3 mM). This suggests that the acid-base properties of TetraPEG-NH2 showing acid-base equilibrium (-NH2 + H(+) ⇆ -NH3(+)) in the solutions play a key role in the gelation process. The acid dissociation constants, pKa's of TetraPEG-NH3(+) and C2ImH(+) (cation of pIL) in aIL were directly determined by potentiometric titration to be 16.4 and 13.7, respectively. This indicates that most of the H(+) ions bind to TetraPEG-NH2 and then C2ImH(+) exists as neutral C2Im. The reaction e...Continue Reading

References

Nov 25, 2000·Angewandte Chemie·P Wasserscheid, W Keim
Sep 21, 2002·Chemical Communications : Chem Comm·R Sheldon
Mar 12, 2005·Angewandte Chemie·Takanori FukushimaTakuzo Aida
Jan 24, 2007·Langmuir : the ACS Journal of Surfaces and Colloids·Takeshi Ueki, Masayoshi Watanabe
Oct 11, 2008·Analytical Sciences : the International Journal of the Japan Society for Analytical Chemistry·Ryo KanzakiShin-ichi Ishiguro
Jul 25, 2009·Nature Materials·Michel ArmandBruno Scrosati
Oct 3, 2009·Accounts of Chemical Research·Jason E BaraRichard D Noble
Nov 5, 2011·The Journal of Physical Chemistry. B·Rachid BarhdadiAndrew Doherty
Jan 24, 2012·Chemical Society Reviews·Hui WangRobin D Rogers
Mar 1, 2012·Chemical Communications : Chem Comm·Shohei KasaharaHideto Matsuyama
Nov 9, 2012·The Journal of Physical Chemistry. B·Ryo KanzakiYasuhiro Umebayashi
Dec 20, 2012·The Journal of Chemical Physics·Kengo NishiMitsuhiro Shibayama
Jun 20, 2013·Journal of the American Chemical Society·Yuanyan GuTimothy P Lodge
Dec 21, 2013·Chemical Communications : Chem Comm·S KasaharaH Matsuyama

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Citations

Sep 18, 2018·The Journal of Physical Chemistry. B·Kei HashimotoMitsuhiro Shibayama

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