A novel membrane fabrication strategy was investigated utilizing a 3D printing technique known as direct-ink writing (DIW), where a viscous polymer dope solution was digitally deposited via robotic control. This technique was used to fabricate polysulfone (PSF) membranes for water treatment, through a non-solvent induced phase inversion method. This talk will focus on the fundamental understanding of the effects of various DIW parameters on membrane separation properties and will compare them against membranes prepared using conventional methods as well as with commercially available polysulfone membranes. This method of fabrication inherently has two distinct advantages over the conventional doctor blade technique <i>viz</i>., – (i) significant reduction in the amount of material (solvents/co-solvents and polymer) needed to manufacture similar-sized membranes and (ii) precise control of the membrane morphological properties (e.g. porosity, pore size distribution). The separation properties are evaluated using long-term solution fluxes as well as via determination of the molecular-weight cut-offs, while the corresponding morphological properties are evaluated using state-of-the-art microscopy and surface characterization techniques. An interesting strategy of utilizing low surface-tension organic solvents, as has been traditionally used for hollow fiber spinning, to improve the long-term stability of these membranes will be discussed in this talk. The DIW-enabled precise control over the membrane properties is expected to enable a wide range of applications for these membranes, especially for emerging water-borne micropollutants, while simultaneously facilitating eco-friendly manufacturing strategies. Such potential applications as well as some strategies for membrane manufacturing scalability will also be covered.

Developing porous polymer membranes via direct ink-writing: A polysulfone-based case study

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.