Culp Tyler E, Ye Dan, Paul Mou, Roy Abhishek, Behr Michael J, Jons Steve, Rosenberg Steve, Wang Cheng, Gomez Esther W, Kumar Manish, Gomez Enrique D
Dow Water and Process Solutions, Edina, Minnesota 55439, United States.
Analytical Sciences, The Dow Chemical Company, Midland, Michigan 48667, United States.
ACS Macro Lett. 2018 Aug 21;7(8):927-932. doi: 10.1021/acsmacrolett.8b00301. Epub 2018 Jul 17.
Characterization of the internal morphology of thin film composite membranes used in reverse osmosis (RO) is a prerequisite for understanding the connection between microstructure and water transport properties and is necessary for the design of membranes with improved performance. Here, we examine a series of fully aromatic polyamide active layers of RO membranes that vary in crosslinking using a combination of resonant soft X-ray scattering (RSoXS), transmission electron microscopy (TEM), and atomic force microscopy (AFM). Analysis of RSoXS profiles reveals a correlation between membrane structure and crosslinking density. Through a combination of scattering contrast calculations, TEM, and AFM micrographs, we assign the dominant contribution to RSoXS data as either surface roughness or chemical heterogeneity, depending on the X-ray energy used. Altogether, our results demonstrate the utility of soft X-ray scattering to examine the microstructure of water filtration membranes.
表征用于反渗透（RO）的薄膜复合膜的内部形态是理解微观结构与水传输特性之间联系的先决条件，也是设计性能更优的膜所必需的。在此，我们使用共振软X射线散射（RSoXS）、透射电子显微镜（TEM）和原子力显微镜（AFM）相结合的方法，研究了一系列交联程度不同的全芳香族聚酰胺RO膜活性层。对RSoXS图谱的分析揭示了膜结构与交联密度之间的相关性。通过散射对比度计算、TEM和AFM显微照片相结合，我们根据所使用的X射线能量，将RSoXS数据的主要贡献归因于表面粗糙度或化学不均匀性。总之，我们的结果证明了软X射线散射在研究水过滤膜微观结构方面的实用性。
