Original article A dependence study: Molecular weight of polyethylene glycol (PEG) ON La 0.7 Sr 0.3 Co 0.2 Fe 0.8 O 3d (LSCF 7328) hollow fiber membrane for oxygen permeation Hamzah Fansuri a,⇑ , Alfia Dewi Masyitoh a , Silvana Dwi Nurherdiana a , Wahyu Prasetyo Utomo a , Triyanda Gunawan a , Nurul Widiastuti a , Mohd Hafiz Dzarfan Othman b , Ahmad Fauzi Ismail b , Subaer c a Department of Chemistry, Faculty of Science and Data Analytics, Institut Teknologi Sepuluh Nopember (ITS), Kampus ITS Sukolilo, Surabaya 60111, Indonesia b Advanced Membrane Technology Research Centre (AMTEC), School of Chemical and Energy Engineering, Universiti Teknologi Malaysia (UTM), Johor Bahru 81310, Malaysia c Material Physics Laboratory, Physics Department, Universitas Negeri Makassar, Jalan Mallengkeri, Parang Tambung, Makassar 90224, Indonesia article info Article history: Received 25 March 2020 Accepted 2 May 2021 Available online xxxx Keywords: Hollow fiber membrane Membrane morphology Phase inversion La 0.7 Sr 0.3 Co 0.2 Fe 0.8 O 3d (LSCF 7328) Perovskite oxide Polyethylene glycol Cleaner Fossil Fuel Technology abstract In an effort for further improvement of LSCF hollow fiber membrane properties in oxygen purification application, this work studied the use of polyethylene glycol (PEG) with different molecular weight of 2000, 3400 and 6000 Da as a pore former. A well-prepared hollow fiber membrane was successfully fab- ricated via extrusion followed by a sintering method. The results showed that the addition of PEG increased the viscosity of the dope suspension and formed a constant asymmetric pore configuration of the membrane after sintering at 1250 °C. The increasing molecular weight of PEG also leads to a decrease in the mechanical strength of the membranes, indicating that finger-like pores were sacrificed by forming irregular pores. The gas tightness was also examined under room temperature which showed that membrane with PEG 3400 achieved the best tightness with the nitrogen permeability of 3.55  10 5 molm 2 s 1 Pa 1 . The oxygen permeation of the membranes was also influenced by the addition of PEG, where the highest oxygen permeation flux of 6.07  10 8 molcm 2 s 1 was obtained using a hollow fiber membrane with PEG 3400 due to the existence of the lowest dense layer thickness. Ó 2021 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). 1. Introduction Perovskite oxide-based mixed ionic-electronic conductor (MIEC) such as LSCF in a membrane form has been extensively studied in recent decades (Sajidah et al., 2018). The membranes show their ability to deliver oxygen ions from the air through the perovskite crystal lattice (Wang et al., 2017). Based on this capabil- ity, it shows higher potential to be used in oxygen controlled cat- alytic processes such as partial oxidation of methane reaction and solid oxide fuel cell application (Ettouney et al., 1995). The unique mechanism of oxygen transfer in MIEC membrane also offer alternative ways for oxygen separation and purification from the air. Proven and mature oxygen separation technology, namely cryogenic distillation and pressure swing adsorption. The cryogenic distillation needs very low temperature while pressure swing adsorption has a problem on abrasion of adsorbent (mostly zeolite) due to pressure swing process (Akulinin et al., 2020). In the last decade, researchers develop membrane for oxygen separation by utilizing zeolitic materials and carbon molecular sieves. How- ever, they exhibit an insufficient performance to separate oxygen from the air because the separation depends on the pore size (Murali et al., 2013; Rossetti et al., 2016) while the size of gasses are similar. In addition to its constituent materials, the pore configuration of the membrane also plays an important role in determining the MIEC membrane performance. Flat membranes, in the form of pel- lets (disc), are widely used in various studies. However, the surface area of flat membrane is small that make them less suitable for large scale application. The thickness directly proportional to the oxygen permeation flux value, which leads to the development of an asymmetrical hollow fiber membrane design. As reported by Chi et al. (2017), the asymmetric pore configuration resulted in high surface area, good stability of the oxygen permeance, and https://doi.org/10.1016/j.jksues.2021.05.003 1018-3639/Ó 2021 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). ⇑ Corresponding author. E-mail address: h.fansuri@chem.its.ac.id (H. Fansuri). Peer review under responsibility of King Saud University. Production and hosting by Elsevier Journal of King Saud University – Engineering Sciences xxx (xxxx) xxx Contents lists available at ScienceDirect Journal of King Saud University – Engineering Sciences journal homepage: www.sciencedirect.com