3D Imaging, Molecular Modeling and Graph Theory of Polyamide Membranes with Interconnected Networked Crumples Reveal Insights on Morphogenesis, Separation Performance and Mechanical Properties
ORAL
Abstract
Polyamide (PA) membranes serve as an active layer in thin-film composite (TFC) membranes used for organic solvent separation. Despite the wide use of TFC membranes, there is little understanding of morphogenesis of the irregular interconnected networked crumple-like 3D nanomorphology of the PA active layer, and its impact on separation and mechanical properties of the membrane. Adopting a multifaceted approach of 3D imaging, morphometry and modeling using low-dose electron tomography, atomic force microscopy (AFM) and coarse-grain (CG) simulations, we present molecular insights into the nanomorphogenesis of networked PA membranes and relate their organic solvent permeabilities and moduli to the 3D nanomorphology. We explore the 3D nanomorphology of three PA membranes with interconnected networked crumples to relate methanol permeance to 3D morphological parameters such as void volume and local membrane thickness. We use CG simulations and 3D thickness mapping to support a coalescence and growth mechanism of membrane morphogenesis. Applying skeletonization to simplify the 3D volume of PA membranes, we quantify the networked PA membranes using graph parameters of network density and efficiency, thereby relating the nanomorphology to the apparent modulus measured by AFM.
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Publication: 1. Submitted papers: An, H.; Smith, J. W.; Ji, B.; Cotty, S.; Zhou, S.; Yao, L.; Kalutantirige, F. C.; Chen, W.; Ou, Z.; Su, X.; Feng, J.; Chen, Q., Mechanism and performance relevance of nanomorphogenesis in polyamide films revealed by quantitative 3D imaging and machine learning. Science Advances 8, eabk1888 (2022).<br>2. Planned papers: Kalutantirige, F. C.; Yao, L.; He, J.; Cotty, S.; Zhou, S.; An, H.; Su, X.; Li, Y.; Chen, Q., 3D Imaging and Graph Theory of Polyamide Membranes with Interconnected Network Crumples Reveal Implications on Separation Performance and Mechanical Properties
