High-Flux pH-Responsive Ultrafiltration Membrane for Efficient Nanoparticle Fractionation

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Efficient nanoparticle fractionation requires membranes with tunable pore sizes.
• Conventional membranes often lack the selectivity and flux needed for precise separation.
• Developing cost-effective and high-performance membranes is crucial for nanoparticle processing.

Purpose of the Study:

• To synthesize amphiphilic pH-responsive copolymers.
• To fabricate isoporous pH-responsive membranes (PPMs) with tunable pore sizes.
• To evaluate the performance of PPMs for nanoparticle fractionation.

Main Methods:

• Grafting polymethacrylic acid (PMAA) onto a P(VDF-CTFE) backbone to create functional copolymers.
• Fabricating isoporous membranes from these copolymers.
• Characterizing membrane pore size, distribution, and flux.
• Testing nanoparticle fractionation using polystyrene nanoparticles of different sizes.

Main Results:

• PPMs exhibited reversible pore size changes with pH variation, ranging from 10.2 to 34.5 nm.
• The membranes demonstrated narrow pore size distribution, leading to higher pure water flux than conventional UF membranes.
• Successful fractionation of 20 nm and 30 nm polystyrene nanoparticles was achieved at specific pH values.

Conclusions:

• The developed pH-responsive PPMs show significant potential for nanoparticle fractionation.
• Tunable pore sizes and uniform pore distribution enhance membrane permeability and selectivity.
• This technology offers a promising approach for cost-effective and efficient nanoparticle separation.