Effect of Poly(ethylene glycol) on Separations by Cellulose Acetate/poly(ether imide) Blend Membranes

Abstract

Ultrafiltration membranes are largely being applied for macromolecular and heavy metal ion separations from aqueous streams. In this study, cellulose acetate (CA) and polyetherimide (PEI) based ultrafiltration blend membranes prepared in the absence and presence of poly(ethylene glycol) 600 (PEG 600) in various compositions were subjected to the separation of macromolecular proteins such as bovine serum albumin (BSA), egg albumin (EA), pepsin and trypsin. Toxic heavy metal ions such as Cu(II), Ni(II), Zn(II) and Cd(II) were subjected to separation by the blend membranes by complexing them with the polymeric ligand polyethyleneimine. The effects of polymer blend compositions and additive concentrations on the rejection and permeate flux of both proteins and metal ions are discussed. In general, it was found that CA=PEI blend membranes displayed higher permeate flux and lower rejection compared to pure cellulose acetate membranes at all additive concentrations. The extent of separation of proteins was found to be directly proportional to the molecular weight of the protein, while the extent of removal of metal ions depends on the affinity of metal ions to polyethyleneimine and the stability of the formed complexes.

Removal of BSA and HA Contaminants from Aqueous Solution Using Amphiphilic Triblock Copolymer Modified Poly(ether imide) UF Membrane and Their Fouling Behaviors

“…The PWF was obtained at trans-membrane pressure (TMP) differences of 69, 138, 207, 276, and 345 kPa, where the resistance of the membrane ( R m , kPa/L m –2 h –1 ) was evaluated from the slope of J w 1 versus TMPs based on the following equation …”

Recent advances in (reactive) melt processing of cellulose acetate and related biodegradable bio-compositions

“…Grafted chains confer high thermoplasticity, elasticity and amorphous nature to the grafted products. 24,37,40 Fig. 3 gives clear evidence for the variation of CA glass transition temperature as determined by dynamic mechanical analysis (DMA).…”

“…20 Transport properties of so-produced membranes showed also improvement in the separation of macromolecular proteins and toxic heavy metal ions. 24 Although poly(3-caprolactone) (PCL), a readily available, reasonably cheap and biodegradable aliphatic polyester displaying good biocompatibility, 16 represents one of the most obvious polymer additives for the modification of CA, its blends are immiscible and generally incompatible. 22,25 Their immiscibility led to an increase in PCL crystallinity and phase separation during melt processing.…”

Influence of the physicochemical environment on membrane-protein binding: investigation using a fabricated PVDF membrane

“…One of the major contributions for accurate and specific membrane-protein binding is made by the intrinsic chemical composition, as well as the optimum membrane morphology [8][9][10][11]. However, in addition to the membrane or sorbent surface, other factors, such as proteins, solvents and other solutes, play a role in the performance of protein binding [12].…”