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Licensed Unlicensed Requires Authentication Published by De Gruyter September 15, 2015

Effect of Alcohols on Phase Stability of Ionic Liquid Microemulsions

Einfluss von Alkoholen auf die Phasenstabilität von Mikroemulsionen mit ionischen Flüssigkeiten
Yongjun Zheng and Yong Zheng


Pseudo-ternary phase diagrams of 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF6) /Tween 80 (polyoxyethylene sorbitan monooleate)/alcohol/toluene systems were constructed with different linear-chain alcohols. The phase diagrams demonstrate that an increase in the surfactant/alcohol weight ratio yields a larger microemulsion domain. The different chain lengths of the alcohols affected the extent of the microemulsion region. Alcohols having short-chain lengths were optimum cosurfactants in bmimPF6-based microemulsion. Moreover, the influence on the microstructure of the single-phase area as a function of the alcohol chain was investigated using electrical conductivity. Preliminary investigations suggested that the bmimPF6-in-toluene region of systems which contain ethanol was notably magnified, and increasing in alcohol chain length (n = 4 – 10) led to a shrinkage for alcohols with longer chain length.


Es wurden pseudo-ternäre Phasendiagramme von Systemen aus 1-Butyl-3-methyl-imidazoliumhexafluorophosphat (bmimPF6) /Tween 80 (Polyoxyethylensorbitanmonooleate)/Alkohol/Toluen erstellt. Es wurden lineare Alkohole mit unterschiedlichen Alkylkettenlängen verwendet. Die Phasendiagramme zeigen, dass der Anstieg des Tensid-Alkohol-Verhältnisses zu einem größeren Mikroemulsionsbereich führt. Die unterschiedlichen Kettenlängen der Alkohole beeinflussen die Größe der Mikroemulsionsregion und Alkohole mit kurzen Ketten waren optimale Co-Tenside in der Mikroemulsion auf bmimPF6-Basis. Außerdem wurde der Einfluss auf die Mikrostruktur des Einphasenbereiches als Funktion der Alkoholkette mittels der elektrischen Leitfähigkeit untersucht. Vorhergehende Untersuchungen deuten darauf hin, dass die bmimPF6-in-Toluen-Region der Systeme, die Ethanol enthalten, deutlich vergrößert war und dass ein Anstieg der Alkoholkettenlänge (n = 4 – 10) zu einer Verkleinerung bei Alkoholen mit längerer Kettenlänge führte.

*Correspondence address, Dr. Yongjun Zheng, Department of Chemical & Environmental Engineering, Anyang Institute of Technology, Anyang, 455000, China, Tel.: +8 60 37 22 90 98 41, E-Mail:

Yongjun Zheng received his Ph. D. from the Graduate University of Chinese Academy of Sciences in 2009. He is now a teacher in the Anyang Institute of Techno-logy. His research interest focuses on the area of ionic liquid microemulsion.

Yong Zheng received his Ph. D. from the University of Chinese Academy of Sciences in 2013, He is now a teacher in the Anyang Institute of Technology. His research interest focuses on the area of ionic liquid.


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Received: 2015-01-12
Accepted: 2015-02-10
Published Online: 2015-09-15
Published in Print: 2015-09-15

© 2015, Carl Hanser Publisher, Munich

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