Parameter Screening of PVDF/PVP Multi-Channel Capillary Membranes

Area of Science:

• Materials Science
• Chemical Engineering
• Membrane Technology

Background:

• Polymeric multi-channel membranes offer enhanced mechanical stability for diverse applications.
• Optimizing fabrication parameters for multi-channel membranes is complex compared to single-channel designs.
• Design of Experiments (DoE) is a valuable tool for investigating complex parameter interplays in membrane fabrication.

Purpose of the Study:

• To investigate the fabrication of seven-channel capillary membranes using polyvinylidene fluoride (PVDF) and polyvinylpyrrolidone (PVP).
• To optimize fabrication conditions using a three-level fractional factorial linear screening design.
• To establish structure-property relationships for PVDF/PVP multi-channel membranes.

Main Methods:

• Fabrication of seven-channel capillary membranes via steam-dry-wet spinning.
• Systematic variation of polymer solution composition (PVDF, PVP) and process temperatures.
• Characterization of membrane morphology using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM).

Main Results:

• Successfully fabricated PVDF/PVP multi-channel membranes with a wide range of flux and retention.
• Achieved high flux (P = 321.4 L/m²/h/bar, R = 18.3% for 500 kDa dextran) and high retention (P = 66.8 L/m²/h/bar, R = 80.0%).
• Identified linear relationships between PVDF concentration, PVP molecular weight, permeability (P), and retention (R).

Conclusions:

• Established fabrication conditions for PVDF/PVP multi-channel membranes with tunable performance.
• Demonstrated the utility of DoE for screening multi-channel membrane fabrication parameters.
• The developed membranes show potential for micro- and ultra-filtration applications.