Immobilization of Ionic Liquid [BMIM][PF₆] by Spraying Suspension Dispersion Method

Abstract

A novel method of immobilizing ionic liquid of 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF6] by spraying suspension dispersion was proposed. The oil phase, composed of [BMIM][PF6], polysulfone, and dichloromethane, was sprayed into the 0.2 wt % gelatin aqueous solution using nitrogen gas pressure to form droplets. As dichloromethane evaporated completely, polysulfone microcapsules, containing the [BMIM][PF6], were obtained. In order to select a suitable shell material and dispersant, several parallel experiments were also carried out, which proved that that polysulfone and gelatin are suitable shell material and dispersant, respectively. The polysulfone microcapsules enclosing ionic liquid were examined using a scanning electron microscope and thermogravimetric analyzer. The results showed that the microcapsules have an average diameter of 70 μm with narrow size distribution and smooth surface, and the encapsulation capacity of microcapsules is 29%.