Probing the Internal Microstructure of Polyamide Thin-Film Composite Membranes Using Resonant Soft X-ray Scattering.
Tyler E CulpDan YeMou PaulAbhishek RoyMichael J BehrSteve JonsSteve RosenbergCheng WangEsther W GomezManish KumarEnrique D GomezPublished in: ACS macro letters (2018)
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.
Keyphrases
- electron microscopy
- atomic force microscopy
- high resolution
- high speed
- white matter
- dual energy
- single molecule
- monte carlo
- magnetic resonance
- molecular dynamics simulations
- density functional theory
- computed tomography
- molecular dynamics
- electronic health record
- multiple sclerosis
- mass spectrometry
- magnetic resonance imaging
- energy transfer
- amino acid
- deep learning