Desalination 206 (2007) 107–126 Presented at EuroMed 2006 conference on Desalination Strategies in South Mediterranean Countries: Cooperation between Mediterranean Countries of Europe and the Southern Rim of the Mediterranean. Sponsored by the European Desalination Society and the University of Montpellier II, Montpellier, France, 21–25 May 2006. *Corresponding author. A theoretical approach on membrane characterization: the deduction of fine structural details of asymmetric nanofiltration membranes A.R. Hassan a , Nora’aini Ali a *, Norhidayah Abdull a , A.F. Ismail b a Department of Science Engineering, Faculty of Sicence and Technology, University College of Science and Technology (KUSTEM), 21030 Mengabang Telipot, Kuala Terengganu, Terengganu Darul Iman, Malaysia Tel. +60 (9) 668-3254; Fax +60 (9) 669-4660; email: noraaini@kustem.edu.my b Membrane Research Unit, Faculty of Chemical Engineering and Natural Resources Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Darul Ta‘zim, Malaysia Received 1 February 2006; accepted 6 June 2006 Abstract In this study, the effects of polymer concentration on the performances and fine structural details of asymmetric nanofiltration (NF) membranes were investigated. Based on the well known models/equations on pore flow, solution diffusion and extended Nernst–Planck, the experimental data (electrolyte/ions rejection) has been modeled. Spielger– Kedem equations were used to determine the membranes parameters such as reflection coefficient, solute permeability and steric hindrance effects. Employing steric hindrance pore model (SHP) model and Teorell–Meyer Sievers (TMS) model, important membranes structural details in terms of effective pore radius, effective charge density and ratio of effective membrane thickness to membrane porosity have been measured. From the modeling results, it was found that the polymer concentration can influence the membrane performances by varying of structural details. Through the observation using scanning electron microscopy (SEM), it was shown that the produced membranes exhibited a finger-like structure. According to the results obtained from the modeling, these membranes are in range of the commercially available NF membranes. Keywords: Nanofiltration; Theoretical model; Polysulfone; Structural details; SEM 0011-9164/07/$– See front matter © 2007 Published by Elsevier B.V. doi:10.1016/j.desal.2006.06.008 brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by Universiti Teknologi Malaysia Institutional Repository