“…In most of the studies on ILbased microemulsions, the IL, such as 1-butyl-3-methylimidazolium tetrafluoroborate (C 4 mim) (BF 4 ), was used as a replacement for water . Nevertheless, some ILs may serve as an appropriate replacement for oil phase, such as 1-butyl-3-methylimidazolium hexafluorophosphate (C 4 mim) (PF 6 ) Behera, Malek & Pandey 2009). Long alkyl chain ILs can also be used as surfactants, which are named as surface-active ionic liquids (Zech et al 2009;Govind et al 2012).…”