Development of graphene oxide incorporated polysulfone/pebax thin-film composite membranes for isopropanol dehydration

• Main Author: Mohamad Syafiq, Abdul Wahab
• Format: Thesis
• Language: English
• Published: 2022
• Subjects: TA Engineering (General). Civil engineering (General); TP Chemical technology
• Online Access: http://umpir.ump.edu.my/id/eprint/35713/1/Development%20of%20graphene%20oxide%20incorporated%20polysulfone%20pebax%20thin-film%20composite%20membranes.ir.pdf; http://umpir.ump.edu.my/id/eprint/35713/

Polymeric membranes separation among the new and reliable separation and purification techniques in term of energy consumption, ease of process, and high selectivity due to polymer properties which can be tailored to specific needs. Recent works on thin film nanocomposite (TFNC) showed that there is still a gap on factors or parameters involved in TFNC synthesis, which the same old weakness of membrane swelling, flux loss and selectivity deficit seem left to be discovered. In this work, graphene oxide (GO) was embedded to both selective hydrophilic layer and porous Polysulfone (PSF) hydrophobic substrate creating a mutual bridge between the two surfaces. Pristine 1-3 µm microporous PSF prepared via dry/wet phase inversion techniques with contact angle of 74.12° has been further studied with GO embedded Pebax dense selective layer. This dual nature thin film nano composite TFNC membranes managed to reduce the water contact angle down to 37.18°. As for the IPA dehydration study, the total flux up to 1.19 kgm–2h–1 and 0 wt% IPA detected in permeate was achieved with 20 wt% water feed at 30 °C. A two-level full factorial design (FFD) was used to analyze several factors involved in PSF–GO–Pebax TFNC membranes development. Permeate flux was chosen as a single response for four possible factors: Pebax selective layer concentration, amount of GO loads to Pebax selective layer, Pebax–GO selective layer thickness, and amount of GO load to PSF substrate. R2 obtained from the analysis of variance (ANOVA) is 0.9937 with Pebax concentration as the highest contributing factor. Pebax concentration–amount of GO load to PSF substrate is the only interaction contributing to the highest flux. A regression analysis concluded the study with model development and an optimized condition for the membrane design. There are two operating conditions for the pervaporation (PV) studied within this system – the amount of water contents in binary feed mixture and operating temperature. The highest possible flux obtained from this study is at 12 wt% –14 wt% of water in IPA and 61 ℃ – 65 ℃ operating temperature with permeate of 1.514 kgm–2h–1 – 1.562 kgm–2h–1. A permeate flux model for this system also been generated and validated with error margin less than 1 % proving the genuine of the developed model and the ability of data prediction.