Journal of Materials & Environmental Sustainability Research (2022), 2(2): 1-10 p-ISSN: 2811-1338; e-ISSN: 2811-132X DOI: https://doi.org/10.55455/jmesr.2022.004 Published by Centre for Energy and Environmental Sustainability Research (CEESR), University of Uyo, Uyo, Nigeria | 1 Original Research Paper Effect of polymer concentrations on pores mechanism in electrospun fibre Samson O. Alayande 1 *, Oluseyi A. Adeyemi 2 , Oyesolape B. Akinsipo 3 , Joshua N. Edokpayi 4 , Gabriel O. Oladipo 5 , Titus A.M. Msagati 6 1 Department of Physical Sciences, First Technical University, Oyo State, Nigeria 2 Department of Mechanical and Mechatronic Engineering, First Technical University, Oyo State, Nigeria 3 Department of Chemical Sciences, Tai Solarin University of Education, Ogun State, Nigeria 4 Department of Hydrology and Water Resources, University of Venda, Thohoyandou 0950, South Africa 5 Department of Science Laboratory Technology, D.S. Adegbenro ICT Polytechnic, Ogun State, Nigeria 6 Nanotechnology and Water Sustainability, University of South Africa, Florida, South Africa *Corresponding author: Samson O. Alayande (samson.alayande@tech-u.edu.ng) Received: January 11, 2022; Revised: April 16, 2022; Accepted: April 25, 2022; Published: May 11, 2022 © 2022 Centre for Energy and Environmental Sustainability Research, University of Uyo, Uyo, Nigeria Handling Editor: Ubong J. Etim Abstract: Advanced material science has resulted in materials with atomic-scale dimensions whose tremendous application includes filtration, drug delivery, membrane, sensor, and encapsulation. Nanoporous fibre has been formed using temperature-induced phase separation (TIPS) and vapour-induced phase separation (VIPS) mechanism, but polymer concentration has been underestimated in the electrospinning parameter. This work aims at showcasing the effect of electrospinning parameters including polymer concentration and resultant phases on pore formation on fibre. Pore formation in electrospun fibre was carried out by electrospinning expanded polystyrene (EPS). The surface morphology of the resulting nanoporous fibre was characterized with Scanning Electron Microscope (SEM) while the pore distribution was analyzed with a BET (Brunauer, Emmet, Teller) micromeritics analyzer. From the result, an increased concentration of polymer from 10 % decreased bead population to zero, meanwhile, bombardment with high electrostatic power resulted in beaded fibres at 10% and 15% w/v. Further increase in EPS concentration resulted in beadless fibres and electrospun 20% EPS fibre at 8.5 kV resulted in porous fibre with meso, micro and macropores. At 11.5 kV, pore dimension in fibre reduced with predominant pore width less than 100 nm. An increased voltage to 13.5 kV resulted in morphologies showing brittled fibre probably due to excess pores formed. Conclusively, polymer concentration moderates variables interaction that resulted in phase separation which controls fibre orientation. Therefore, pore formation does not solely depend on TIPS, VIPS, and breath figures but also polymer concentration. Keywords: nanofibre; electrolysis; pore orientation; concentration; mechanism DOI: 10.55455/jmesr.2022.004 1. Introduction In the last two decades, the multifaceted application of expanded polystyrene (EPS) in roofs and walls of buildings, containers, packaging materials etc. has propelled its massive production. Meanwhile, the lack of suitable disposal facilities and reuse of EPS remains a consequential global issue, instead, its environmental pile- up is increasingly unsettling (Uttaravalli et al. 2020). Annually, polystyrene (PS) occupies 10 wt. % of the total plastic waste produced in the last ten years, while its monomer, styrene is as a toxin capable of causing cancer. Styrene has also been suspected to be toxic to the gastrointestinal tract (GIT) including the respiratory and renal systems. Efforts made to solve its environmental implication returned with deleterious effects such as global warming and the persistence of plastic waste (Hidalgo-Crespo et al. 2022). Therefore, sustainable management and effective utilization of EPS for advanced applications need to be considered as a solution. Different