Interfacially polymerized polyamide thin film composite membranes: Preparation, characterization and performance evaluation Adel Soroush a , Jalal Barzin a, ⁎, Mahdi Barikani a , Mahdi Fathizadeh b a Iran Polymer and Petrochemical Institute, P.O. Box 14965/115, Tehran, Iran b Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran abstract article info Article history: Received 25 May 2011 Received in revised form 5 July 2011 Accepted 20 July 2011 Available online 17 August 2011 Keywords: Thin film composite membrane Interfacial polymerization Membrane characterization Performance evaluation The formation of polyamide thin film composite (TFC) membranes via interfacial polymerization (IP) of m- phenylenediamine (MPD) in water with trimesoyl chloride (TMC) in hexane was studied. Parametric studies were conducted by varying reaction time, curing time and curing temperature. It is evident from the results that increasing the polymerization time results in decreasing the membrane surface roughness and increasing solid–liquid interfacial energy. Also with increasing the polymerization time, surface morphology changes from “nodular” and “leaf like” morphology to “hill and valley”. The other involving parameters were the thin film thickness, which the results indicated that PA thin film thickness increased with polymerization time and moreover the acidic feature of PA film varied during polymerization process. Increasing polymerization time led to decreasing membrane water flux and increasing salt rejection since the PA layer became thicker and the extent of cross-linking increased. Also, it was shown that the curing conditions affect on membrane performance and with increasing curing time and temperature, salt rejection was increased and flux was decreased. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Several methods can be carried out in desalination and industrial water treatment. Reverse osmosis (RO) is one of these methods which are simple to operate in comparison with other separation processes are widely used in chemical, environmental and food industries [1–6]. Most of the commercially successful RO and nanofiltration (NF) membranes are thin film composite (TFC) membranes which consist of a barrier active dense layer and a porous sublayer. This active layer is usually formed via interfacial polymerization (IP) technique which can provide good selectivity and high water permeation rate. One of the successful TFC membranes is polyamide (PA) composite membranes. PA active layer polymerized interfacially on top of polysulfone (PS) and polyethersulfone (PES) porous support membrane [7–11]. Between a wide range of reactive monomers used in IP process to produce PA layer, m-phenylene diamine (MPD) and trimesoyl chloride (TMC) have special importance since they provide aromatic cross-linked PA layer and hence provide high water flux. In this IP process, the immiscible aqueous and organic phases brought together and a thin film immediately formed between two phases at the organic side of the interface due to low solubility of acid chloride in water and fairly good solubility of amines in organic solvents [12,13]. The interfacial polymerization time is very fast and many factors such as reaction time, reaction temperature, curing conditions and monomer concentration can affect PA structure. Also, the produced film is extremely thin so its characterization by common methods used in the bulk polymer characterization is not possible and therefore use of surface analysis methods is necessary. TFC membranes preparation has been studied by different groups of researchers who focused on several fields such as effect of PA molecular structure on membrane properties and performance [14], mechanical properties of thin film layer [15], surface feature [16], transport modeling and mathematical modeling of interfacial polymerization [17,18] and use of nanozeolite particle in thin film nanocomposites [19]. In this study, PA TFC membranes were prepared by interfacial polymerization of MPD and TMC as two important and widely used monomers in IP process on top of the PES porous support membrane which prepared by non-solvent induced phase separation. PES has been studied thoroughly and is well known for its proper properties such as favorable mechanical strength, thermal and chemical stability and excellent biocompatibility [20–24]. Several TFC were prepared under different polymerization conditions such as polymerization time, curing time and curing temperature. The effect of polymerization time as one of the important kinetic parameters on active layer thickness, morphology, structure, hydrophilicity, roughness and thermal properties were investigated by scanning electron microscopy (SEM), attenuated total Desalination 287 (2012) 310–316 ⁎ Corresponding author at: Biomaterials Department, P.O. Box 14965/115, Iran Polymer and Petrochemical Institute, Tehran, Iran. Tel.: + 98 21 44580050; fax: + 98 21 44580161. E-mail address: j.barzin@ippi.ac.ir (J. Barzin). 0011-9164/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.desal.2011.07.048 Contents lists available at ScienceDirect Desalination journal homepage: www.elsevier.com/locate/desal