All events are in Central time unless specified.

CHME/NCMN Seminar w/ Isabel Escobar

Sustainability & scale-up: an evolution in polymeric membrane manufacturing using green solvents and slot die coating for water treatment

2:00 pm – 3:00 pm
Othmer Hall Room: B201
820 N 16th St
Lincoln NE 68508
Additional Info: OTHM
Target Audiences:
Shudipto Dishari,

In light of increasing clean water insecurity, polymeric membranes are playing a major role as more efficient and scalable filters. A variety of techniques for polymeric membrane fabrication have been studied and implemented, with nonsolvent-induced phase separation (NIPS) being one of the most prevalent methods. However, the frequent use of hazardous solvents that are derived from nonrenewable resources hinders the safety and sustainability of NIPS; moreover, increasing regulations on traditional solvents have motivated commercial manufacturers to identify alternative solvents with green properties. While bench-scale studies on green solvent-based polymeric membranes have emerged, the next step of manufacturing scale-up to meet the needs of the commercial sector remains largely unstudied.

This study addresses the next step by developing a novel scaled-up manufacturing NIPS method for green solvent-based polysulfone (PSf) membranes via slot die coating (SDC). The SDC setup was configured for continuous processing by using a roll-to-roll system. PSf dope solutions included Rhodiasolv® PolarClean and gamma-valerolactone (GVL), two nontoxic and biodegradable solvents that have been relatively understudied in membrane synthesis. Dope solution properties, including viscosity and surface tension, were analyzed to determine the optimal parameters for fabricating ultrafiltration (UF) membranes via SDC. A comparison study of filtration characteristics was conducted between PSf-PolarClean-GVL UF membranes fabricated via bench-scale blade-casting and SDC. Membrane morphology, surface composition, and hydrophilicity were characterized. Profiles of both membrane types were compared with those exhibited by PSf UF membranes derived from the traditional solvent N-methyl-2-pyrrolidone (NMP).

Under dead-end filtration conditions, PSf-PolarClean-GVL membranes fabricated via SDC exhibited a high average deionized water permeability of 152.5 ± 27.3 LMH/bar and a maximum bovine serum album (BSA) rejection of 98.2 ± 1.4%, which indicated close agreement with a blade-casted counterpart. The complete results highlight the value of green solvents and SDC in bringing sustainable and scaled-up polymeric membranes closer to implementation.

Download this event to my calendar