Environmentally-safe anion exchange membranes of PVA/PDDA/SiO2composite for reverse electrodialysis

• Published in: International Journal of Thermofluids 2023-05, Vol.18, p.100350, Article 100350
• Main Authors: Wibisono, Yusuf, Anggraeni, Eka Tiyas, Argo, Bambang Dwi, Nugroho, Wahyunanto Agung, Maharsih, Inggit Kresna, Bilad, Muhammad Roil
• Format: Article
• Language: English
• Subjects: anion exchange membrane; electrodialysis; energy generation; permselectivity; reverse electrodialysis; wastewater treatment
• ISSN: 2666-2027; 2666-2027
• DOI: 10.1016/j.ijft.2023.100350

•Anion Exchange Membranes (AEMs) is successfully syntesized from PVA/PDDA co-polymers by using different solvents.•Colloidal silica (SiO2) is used as inorganic filler to enhance membrane strength and adjust membrane porosity.•DMSO showed the best yields where area resistance (AR), swelling degree (SD), and fixed charged density (FCD).•Utilization of water as solvent in the preparation of AEMs from PVA/PDDA/SiO2 mixture produce equivalent ion exchange properties, yet environmentally-safe. Anion Exchange Membranes (AEMs) are positively charged polymer membrane used in many applications. In RED systems, AEMs could be used to separate ions to produce energy, and on the other hands remove unwanted molecules in wastewater. This study used three masses of colloidal silica (SiO2) as inorganic filler, three mass ratios of polymer mixture (where; PVA as an inert polymer and PDDA as an active polymer) and three different solvents (H2O, DMSO, and DMF), to produce composite AEMs. The properties of fabricated membranes, were measured to be used in the RED systems. RED membranes produced by DMSO showed the best yields where area resistance (AR), swelling degree (SD), and fixed charged density (FCD) were 1.69 k.Ω.cm2, 31.56%, and 0.26 mmol/g H2O, respectively, at the mixed mass ratio φ(PDDA/PVA)/SiO2 of AEM (0.528:0.4; DMSO). SiO2 can create a layer that can strengthen the matrix membrane, formed through -C(=O)-O-C- and -Si-O-Si- bonds. SiO2 can also encourage the formation of quaternary ammonium bonds. The higher the ratio of the mixture used can increase the number of quaternary ammonium bonds to improve AR and permselectivity. The use of water as solvent in the preparation of AEMs from PVA/PDDA/SiO2 mixture is also promising, by produce equivalent ion exchange properties, yet environmentally-safe.