Contemporary Engineering Sciences, Vol. 11, 2018, no. 1, 33 - 41 HIKARI Ltd, www.m-hikari.com https://doi.org/10.12988/ces.2018.712205 Physicochemical Characterization of SEPS Block Copolymer Membranes for CO 2 Separation Acevedo Morantes María, Tapia Alejandra and Realpe Jiménez Álvaro Department of Chemical Engineering, Research Group of Modeling of Particles and Processes, University of Cartagena, Av. Consulado, Cartagena - Colombia Copyright © 2018 Acevedo Morantes María et al. This article is distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract The sulfonation and incorporation of diethanolamine (DEA) in Styrene- ethylene-propylene-styrene (SEPS) block copolymer membranes affected the porosity and water uptake of polymer matrix. Changes in hydrophilicity of polymer were identified through contact angle that is related with the influence on the transportation of gases trough the membrane. The SEPS-membranes were characterized by Fourier Transform Infrared Spectroscopy (FTIR) to elucidate the effects of modifications on the chemical structure. The membranes that were sulfonated for three hours without a carrier (3S 0C) possessed the lower angle contact, higher hydrophilicity, that was related with increase in the permeability and selectivity in other studies. Keyword- CO2 separation membranes, sulfonation, diethanolamine, carrier molecule, contact angle 1 Introduction Although the market of membranes is only 2% of application in new natural gas separation equipment [1], the scientific community has developed appreciable advances on membranes design and development, which shows a substantial potential as an alternative in separation technology due to a simple design, module equipment, small footprint and maintenance [2]. Other gases which could being in the feed, for instance nitrogen (N2), do not interact with diethanolamine (DEA), and their transports through the membrane occurs only by the physical mechanism of diffusion [3]. The permeability of gases,