Designing Electric Field Responsive Ultrafiltration Membranes by Controlled Grafting of Poly (Ionic Liquid) Brush

Abstract

Electric responsive membranes have been prepared by controlled surface grafting of poly (ionic liquid) (PIL) on the commercially available regenerated cellulose ultrafiltration membrane. The incorporation of imidazolium ring on membrane surface was evidenced by FTIR (Fourier transformed infra-red) and EDX (energy-dispersive X-ray) spectroscopy. The PIL grafting resultedin a rougher surface, reduction in pore size, and enhancement in hydrophilicity. The interaction of the electric field between the charged PIL brush and the oscillating external electric field leads to micromixing, and hence it is proposed to break the concentration polarization. This micromixing improves the antifouling properties of the responsive membranes. The local perturbation was found to decrease the water flux, while it enhanced protein rejection. At a higher frequency (1kHz) of the applied electric field, the localized heating predominates compared to micromixing. In the case of a lower frequency of the applied electric field, more perturbation can lead to less permeability, whereas it will have a better effect in breaking the concentration polarization. However, during localized heating at a higher frequency, though perturbation is less, a heating induced reduction in permeability was observed. The electric field response of the membrane was found to be reversible in nature, and hence has no memory effect.

Application of Zwitterions in Forward Osmosis: A Short Review

“…The first step is to immobilize the initiator, the site for polymer growth. The second step involves the controlled polymerization of the zwitterionic monomer, mainly utilizing the equilibrium of Cu 2+ /Cu 1+ salt ( Figure 6 ) [ 79 , 80 , 81 ]. The duration of the initiator immobilization step influences the grafting density, while the length of the zwitterionic polymeric chain was influenced by the duration of the 2nd step of ATRP.…”

Recent advances in poly(ionic liquid)s for biomedical application

“…1 The excellent properties and rich chemical structure banks have aroused wide interest among researchers. 2,3 Ionic liquids are ionized reagents with excellent physicochemical characteristics such as good solubility and biocompatibility, 4 low vapor pressure, and non-flammability. 5 PILs share precisely tunable physical and chemical properties with ILs; 6 they also have the intrinsic properties of polymers, such as improved mechanical stability and dimensional control.…”

Utilization of ionic liquids for preferential separation of thorium during the determination of trace metallic constituents in thorium matrix using ICP-OES

“…34–37 By grafting poly(ionic liquid) brushes on the membrane surface, ionic liquid-based membranes have recently been employed for electric field sensing, unconventional pi–pi interaction-based separation and improvement in antimicrobial characteristics. 38–42 In nuclear industries, so far ionic liquids have been used in the back end of the nuclear fuel cycle either in aqueous or in non-aqueous reprocessing. In non-aqueous reprocessing, ionic liquids have been used for spent fuel dissolution directly into them, and subsequent electro-deposition of required metal ions from them to avoid the criticality issue.…”