Polyelectrolyte multilayer modified nanofiltration membranes for the recovery of ionic liquid from dilute aqueous solutions

Abstract

The feasibility of nanofiltration membranes fabricated by static polyelectrolyte layer-by-layer deposition of poly(styrene sulfonate) and poly(allylamine hydrochloride) on poly(ether sulfone) ultrafiltration and alumina microfiltration membranes for the recovery of ionic liquid from low molecular weight sugar was investigated. The surface properties of these modified membranes were correlated with their performances. The selectivity for 1-butyl-3-methylimidazolium chloride over cellobiose and glucose was found to be as high as 50.5/2.3 for modified alumina and 32.3/3.5 for modified poly(ether sulfone) membranes with optimized number of bilayers. The values for membrane permeance were 4.8 and 2.5 L m 21 h 2 bar 21 , respectively. For low depositions, the separation mechanism was predominantly governed by size-exclusion. For higher depositions, the enhanced negative zeta potential of the modified membranes suggested preferred dominating electrostatic interactions, resulting in high selectivity of ionic liquids over low molecular weight sugars. At very high depositions, the molecular weight cut-off of the membrane becomes constricting for size-exclusion effect.

High‐performance composite nanofiltration membranes fabricated via ternary mixture: Complementary preponderance of the fluorine‐containing monomer 2,2′‐bis(1‐hydroxyl‐1‐trifluoromethyl‐2,2,2‐triflutoethyl)‐4,4′‐methylene dianiline and the rigid monomer bisphenol F

“…BHTTM (98.5 wt %) was synthesized in our laboratory (Figure ). Detailed information on BHTTM is shown elsewhere . TMC (98.0 wt %) was obtained from Qingdao Benzo Chemical Co. (Qingdao, China).…”

“…In the past few decades, nanofiltration (NF) has experienced rapid development because of its distinguished advantages, including its high selectivity to divalent ions and monovalent ions, high flux, and low cost. As versatile separation tools, NF membranes have been widely applied in many domains . Interfacial polymerization (IP) is the most common method for the fabrication of polyamide NF membranes .…”

Preparation and characterization of PVDF‐based blend membranes as polymer electrolyte membranes in fuel cells: Study of factor affecting the proton conductivity behavior

“…There has been considerable interest, driven by the long lifetime and increasing ionic conductivity of energy storage devices, to develop a new generation of electrolyte materials as advanced electrolytes and replace the conventional electrolyte used in many applications . Solid polymer electrolytes are increasingly gaining interest in order to use as advanced electrolyte materials for a wide range of applications such as fuel cells, batteries, sensors, and other energy supply systems . In this case, the performances of solid polymer electrolytes as electrolyte materials is affected by their ionic conductivity, electrical insulating, mechanical, and electrochemical properties.…”

Improvement in antifouling and separation performance of PVDF hybrid membrane by incorporation of room‐temperature ionic liquids grafted halloysite nanotubes for oil–water separation

“…A highly energy‐efficient and broadly applicable approach for effective separation of oil–water mixtures, especially surfactant‐stabilized emulsions, remains highly desired . To date, modified membrane technology has been witnessing a booming era through continuous development both in academic and industrial fields, which has been generally acknowledged as an effective method for the separation of oil–water emulsions owing to their remarkable advantages such as high oil‐removal efficiency, low energy consumption, and relatively simple process …”

“…However, as typical inorganic additives, HNTs are prone to aggregate in membrane matrix or leach out to the coagulation bath during the phase inversion process. Therefore, it is difficult for HNTs to disperse uniformly in membrane matrix, which needs to be overcome urgently . One of the effective methods is to graft chemicals which have good compatibility with organic materials onto the hydrophilic additives, thus enhancing the dispersibility of the hydrophilic additives and developing specific interactions between additives and polymer matrix .…”