Microanalysis of Reverse Osmosis and Nanofiltration Membranes

Abstract

AbstractIn reverse osmosis (RO) and nanofiltration (NF) membranes, the active layer constitutes the main barrier to the transport of water and contaminants. In addition, membrane–foulant interactions occur at the active layer surface. Accordingly, the characterization of active layer properties, and interactions with water, contaminants, and foulants, greatly benefits membrane development and optimization cycles. In this article, we provide a brief review of eight characterization techniques that have proved to be useful for the aforementioned characterization objectives. The techniques covered are positron annihilation lifetime spectroscopy (PALS), Rutherford backscattering spectrometry (RBS), X‐ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR) spectroscopy, electrical/electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). For each technique, we first describe basic concepts and then provide an overview of some key applications and findings of the technique in RO/NF membrane characterization.