Synthesis of the novel symmetric buckypaper supported ionic liquid membrane for the dehydration of ethylene glycol by pervaporation

• Published in: Separation and purification technology Vol. 143; pp. 135 - 145
• Main Authors: Ong, Yit Thai, Tan, Soon Huat
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.03.2015
• Subjects: Buckypapers; Carbon nanotubes; Dehydration; Ethylene glycol; Ionic liquids; Membranes; Pervaporation; Polyvinyl alcohols; Separation; Supported ionic liquid membrane; Symmetry; Carbon nanotubes; Buckypapers; Supported ionic liquid membrane; Pervaporation
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2015.01.021

•Synthesis of SILM by using BP as porous support to form a so-called BP-SILM.•The use of BP increase the amount of the immobilized [Bmim][BF4]–PVA.•The [Bmim][BF4] significantly improve BP-SILM pervaporation performance. In this study, a novel symmetric supported ionic liquid membrane (SILM) was prepared by infiltrating 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF4] into a buckypaper (BP) to form a so-called buckypaper supported ionic liquid membrane (BP-SILM). The [Bmim][BF4] was blended with polyvinyl alcohol (PVA) prior to the infiltration. The role of BP as a support can effectively entrap the infiltrated [Bmim][BF4]–PVA in the interstitial pores and supply the necessary mechanical stability for the resulting BP-SILM. The BP-SILM structure, in which the membrane and support phases were merged into a single layer, was found to be different from that of conventional asymmetric membranes. The BP-SILM structure allows the formation of a thinner symmetric membrane without compromising its mechanical properties. During the application of the BP-SILM in the pervaporation process to dehydrate ethylene glycol aqueous solution, the presence of BP and [Bmim][BF4] was observed to significantly enhance the separation performance and enhance the intrinsic membrane permeability. The BP-SILM exhibited high pervaporation performance with a permeation flux of 102gm−2h−1, a separation factor as high as 1014, and a water permeance of 9046gpu. The BP-SILM also demonstrated a robust pervaporation performance over an operation of 120h.