Solute flux coupling in a homopore membrane

Area of Science:

• Membrane science
• Physical chemistry
• Transport phenomena

Background:

• Previous research investigated solute drag on frog skin and synthetic heteroporous membranes.
• Solute drag involves the interaction between a driver solute and a tracer solute across a membrane.

Purpose of the Study:

• To investigate solute drag on a synthetic homoporous membrane.
• To determine the influence of driver solute concentration and pore size on tracer solute flux asymmetry.

Main Methods:

• Utilized a synthetic homoporous polycarbonate membrane (150-Å radius pores, 6-µm thick, 6 x 10^8 pores cm^-2).
• Employed sucrose as the driver solute, with bulk flow inhibited by hydrostatic pressure.
• Assessed transmembrane asymmetry of tracer solutes (sucrose, maltotriose, inulin, dextran) at varying sucrose concentrations.

Main Results:

• Tracer sucrose exhibited no solute drag.
• Appreciable solute drag was observed for maltotriose at 1.5 M sucrose.
• Solute drag was detectable for inulin and dextran at 0.5 M sucrose.
• Tracer flux asymmetry was dependent on driver solute concentration and pore size.

Conclusions:

• Transmembrane solute drag arises from kinetic and frictional interactions between driver and tracer solutes.
• Findings on homoporous membranes align with previous results on heteroporous membranes.
• Pore size significantly influences the magnitude of tracer flux asymmetry in solute drag phenomena.