Effect of sulfated seaweed polysaccharide on flat sheet polymer (Polysulfone) membrane properties

• Published in: Chemical engineering journal advances 2022-08, Vol.11, p.100314, Article 100314
• Main Authors: Lakshmi, D. Shanthana, Saxena, Mayank, Radha, K.S., Dass, Lawrence Arockiasamy
• Format: Article
• Language: English
• Subjects: Green algae; Polysulfone; Sulfated polysaccharide; Ulvan
• ISSN: 2666-8211; 2666-8211
• DOI: 10.1016/j.ceja.2022.100314

•Polysulfone / Ulvan / DMF, NMP, THF, flat sheet membranes were successfully fabricated.•Effect of solvents on membrane preparation and characterization was also investigated.•Surface roughness factor was influenced by Ulvan (0.5-2.0 wt. %) concentration.•Contact angle gradually decreases with increase in Ulvan concentration from 0.5-2.0 wt. %. Highly sustainable green seaweed derived hydrophilic sulfated polysaccharide Ulvan was (0.5 -2.0 wt. %) blended with 15wt.% polysulfone (PSf) and used as homogenous dope solution for membrane fabrication. PSf / Ulvan polymer dope solution was prepared with four different hydrocarbon solvents, N, N dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methyl 2-pyrrolidone (NMP) and -dimethyl acetamide (DMAc). Out of these four solvents, DMSO stood out to be an incompatible one for PSf,/ Ulvan composite solution. However, PSf/Ulvan membranes were successfully fabricated with the other three solvents. Flat sheet membranes thus synthesized were characterized using pure water flux, macromolecule rejection, ATR-IR, AFM, contact angle and porosity. AFM analysis confirmed that, Ulvan influenced the surface roughness and morphology of the membranes. An appreciable change in surface roughness was noted with an increase in Ulvan concentration in the dope soultion. Contact angle values were measured and it supported the behavior of Ulvan, especially the hydrophilic surface property. The effect of Ulvan as an additive (porogen) in the PSf membrane had a very high influence in the efficiency and morphological properties. Similarly, promising results were obtained with BSA rejection ranging from 78.53% to 72.36% for a time duration of 12 hours with DMAc solvent and 81.19% to 75.49%. for the time duration of 12 hours with NMP as solvent. With the increase in the concentration of Ulvan from 0%to 2.5%, the flux increased from 581.8 to 991.3 LMH with DMAc as solvent. Similarly, with NMP as a solvent, the flux increased from 571.8 to 974.8 LMH. [Display omitted]