Enhancing flux rates and energy efficiency in membrane distillation through stearic acid-electrosprayed membranes

• Published in: Applied surface science 2025-02, Vol.682, p.161625, Article 161625
• Main Authors: Silva, Angelo O., Paulazzi, Alessandro R., Machado, Ricardo A.F., Marangoni, Cintia, Hotza, Dachamir
• Format: Article
• Language: English
• Subjects: Electrospray crystallization; Energy characteristics; Heat transfer; Membrane distillation; Membrane surface modification
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2024.161625

[Display omitted] •Stearic acid electrospray crystallization applied to commercial PTFE, PVDF, and PA membranes.•Significant increase in water-permeated flux for PTFE and PVDF membranes.•Enhanced thermal performance for PTFE, moderate improvement for PVDF, reduced efficiency for PA.•Lower energy demand in the rate-limiting step, improving overall energy efficiency. This study investigates the effects of stearic acid-electrosprayed coatings on commercial PTFE, PVDF, and PA membrane substrates for membrane distillation (MD). Drawing inspiration from prior research involving carbon nanotube modifications, stearic acid was selected for its ability to increase hydrophobicity and reduce heat transfer resistance. The stearic acid was electrosprayed from an ethanol solution onto the substrates, which were subsequently characterized by contact angle, liquid entry pressure, and thickness measurements. The results showed a notable flux increase of 131 % for PTFE and 17 % for PVDF, but a decrease of 56 % for PA. A heat transfer model suggests that stearic acid improves flux by lowering heat transfer resistance in PTFE and PVDF substrates. This study highlights the potential of stearic acid coatings to enhance MD performance, providing valuable insights into improving flux and energy efficiency in MD applications.