Permeability and Separation Characteristics of Polypeptide-Functionalized Polycarbonate Track-Etched Membranes

Abstract

The use of polypeptide-functionalized membranes with known porosity and uniform pore sizes allows a better understanding of the separation characteristics in nanodomains. A stimuli-responsive polypeptide, poly-L-glutamic acid (PLGA), was immobilized on a polycarbonate track-etched (PCTE) membrane. First, PCTE membrane was gold-coated under convective conditions, and a thiol, 3-mercapto 1,2-propanediol (MPD), was chemisorbed on the modified surface. Second, the MPD molecule was oxidized with sodium periodate to obtain an aldehyde functionality, which was further reacted with the amino group on the PLGA molecule, making possible a single point polypeptide attachment. The morphology of the modified membrane was analyzed by electron microscopy (SEM, TEM) imaging, confirming uniform structure. Modified membrane performances, with starting diameters of 30 and 100 nm, were evaluated in terms of solute (ionic and neutral) rejections and water permeability. Both solute and water transport through membrane were reversibly regulated by pH. The effective membrane charge was calculated using the extended Nernst-Plank equation coupled with Donnan equilibrium and electroneutrality conditions.

pH‐Responsive Nanoporous Silica Colloidal Membranes

“…Alternatively, steric selectivity has been achieved by modifying the nanopore surfaces with polymer molecules that respond to environmental stimuli. [8] For instance, the water permeation rate through track-etched nanopores produced in polymeric films has been controlled by grafted macromolecules that respond to changes in environmental conditions, including pH, [9,10] light, [11] and ion concentration. [12] A number of polymer-based stimuli-responsive membranes have been recently developed.…”

A new hybrid ion exchange-nanofiltration (HIX-NF) separation process for energy-efficient desalination: Process concept and laboratory evaluation

“…Of the two, the membrane-based reverse osmosis (RO) processes have made significant strides during the last three decades and are being widely used around the world [3][4][5][6][7][8][9][10]. However, the cost-effectiveness of RO processes is adversely affected by Understandably, current research emphasis is directed toward improving the membrane material for robustness and higher permeate flux [8,10,[11][12][13][14][15][16]. Concurrently, significant progresses have been made toward the development of forward osmosis (FO) and membrane distillation processes [17][18][19][20][21].…”

Nanoporous polymeric materials: A new class of materials with enhanced properties

“…Smuleac and coworkers [195] demonstrated that the MWCO of Na 2 SO 4 salt was higher in the membranes with lower pore sizes (a difference up to 800% for a feed concentration of 2 mM).…”

“…Other nanoporous polymeric systems such as polyimide [193], polyethylene [194], or polycarbonate (PC) [195] have also been investigated. Smuleac and coworkers [195] demonstrated that the MWCO of Na 2 SO 4 salt was higher in the membranes with lower pore sizes (a difference up to 800% for a feed concentration of 2 mM).…”

“…However, more work is needed to obtain finer porous structures and to carry out experimental measurements to confirm their applicability. [171,186,187,195]. Right: Normalized separation factor for different polymeric and non-polymeric nanoporous membranes [151,159,186].…”