Leveraging Liquid-Liquid Interfaces in a 3D-Printable Reactor to Form Sub-Micron Freestanding Membrane Selective...

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Fabricating ultrathin, defect-free polymer nanofilms for thin-film composite (TFC) membranes is challenging due to substrate interference and limited reproducibility.
• Existing methods often struggle with solution intrusion and film transfer, hindering consistent performance.

Purpose of the Study:

• To introduce a modular, cost-effective, 3D-printed reactor, FIPzR, for fabricating defect-free polymer films at liquid-liquid interfaces.
• To demonstrate substrate-independent fabrication of high-quality polymer nanofilms with controlled morphologies.
• To enable direct transfer of fabricated films onto diverse substrates.

Main Methods:

• Utilized Computer-Aided Design (CAD) and additive manufacturing (AM) to engineer the FIPzR device.
• Employed interfacial polymerization for polyamide (PA) membranes, drop casting for polysulfone (PSU), and reactive curing for polydimethylsiloxane (PDMS).
• Evaluated desalination performance of PA membranes and gas separation of PSU and PDMS membranes.

Main Results:

• Achieved reproducible fabrication of polymer nanofilms with thicknesses from <20 nm to submicron scales.
• Demonstrated high water permeance and salt rejection for PA membranes in reverse osmosis (RO) conditions.
• Confirmed structural integrity and defect-free quality of PSU and PDMS membranes with CO2/N2 selectivity matching literature benchmarks.

Conclusions:

• The FIPzR reactor provides a reproducible and substrate-independent method for polymer nanofilm fabrication.
• This technology has significant potential for applications in membrane separations, coatings, flexible electronics, and sensing.