Solvent recovery from photolithography wastes using cellulose ultrafiltration membranes


Savaş Alkan A., Çulfaz Emecen P. Z.

Journal of Membrane Science, vol.647, 2022 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 647
  • Publication Date: 2022
  • Doi Number: 10.1016/j.memsci.2022.120261
  • Journal Name: Journal of Membrane Science
  • Journal Indexes: Science Citation Index Expanded, Scopus, Academic Search Premier, PASCAL, Aqualine, Biotechnology Research Abstracts, Chimica, Compendex, EMBASE, Food Science & Technology Abstracts, INSPEC, Metadex, Pollution Abstracts, DIALNET
  • Keywords: Cellulose membrane, Alkaline hydrolysis, Organic solvent ultrafiltration, Photolithography, PGMEA, NANOFILTRATION MEMBRANES, RESISTANT NANOFILTRATION, MOLECULAR SEPARATION, TRANSPORT, ACETATE, SU-8, PERFORMANCE, PERMEATION, CATALYST, FIBERS

Abstract

© 2022 Elsevier B.V.Solvent recycling and reuse are indispensable for ensuring a sustainable chemical industry and circular economy. In this study we report the fabrication of cellulose ultrafiltration membranes and their application in recovery of propylene glycol methyl ether acetate (PGMEA) used as developer solvent in SU-8 photolithography. Cellulose membranes were fabricated via alkaline hydrolysis of cellulose acetate membranes in aqueous NaOH. Membrane permeance and molecular weight cut-off (MWCO) were tuned via changing cellulose acetate concentration in precursor solution and evaporation of volatile co-solvent, acetone. MWCO of the membranes was found to be smallest in DMSO, followed by water and largest in methanol. The difference was attributed to the different hydrodynamic diameters of the probe molecules in these solvents. SU-8 rejection from its representative developer solutions in PGMEA was assessed in dead-end filtration at up to 80% permeate recovery. After the first filtration, the collected permeate was fed to the same membrane to simulate a two-stage filtration scenario. Rejection was in the range of 87%–89% in a first stage filtration and 79%–80% in a second stage, both operated at 80% permeate recovery. Recycled solvent could be used in photolithography although with some loss of pattern fidelity, possibly owing to remaining SU-8 and photoacid generator in PGMEA.