Impact of Water Extraction on Malonamide Aggregation: A Molecular Dynamics and Graph Theoretic Approach
| Autor: | L. Soderholm, Marek Piechowicz, Michael J. Servis |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
010304 chemical physics
Chemistry Intermolecular force Aggregate (data warehouse) Water Water extraction Molecular Dynamics Simulation 010402 general chemistry 01 natural sciences Malonates 0104 chemical sciences Surfaces Coatings and Films Characterization (materials science) Solutions Molecular dynamics Chemical physics 0103 physical sciences Amphiphile Materials Chemistry Molecule Physical and Theoretical Chemistry Topology (chemistry) |
| Zdroj: | The Journal of Physical Chemistry B. 125:6629-6638 |
| ISSN: | 1520-5207 1520-6106 |
| Popis: | Solution structure in liquid-liquid extraction affects the efficacy of separation; however, even for simplified organic phases, structural characterization and attribution of aggregation to intermolecular interactions are fundamental challenges. We investigate water uptake into organic phases for two malonamides commonly applied to actinide and lanthanide separations. Extracted water induces reorganization of the amphiphilic extractant molecules, although we find this rearrangement is not strongly manifested in small-angle X-ray scattering making it challenging to probe without methods such as atomistic simulation. Using a graph theoretic approach to define hydrogen bonded water/malonamide aggregates from molecular dynamics simulations, we find evidence of a characteristic aggregate size by water number that results from geometric accommodation of the surrounding malonamide molecules. This implies a degree of size selectivity inherent to these water-in-oil aggregates. Conversely, we find no evidence of a characteristic size of the aggregates with respect to their malonamide number. By defining a separate graphical representation of self-association of the amphiphilic malonamides, we quantify how water affects the local and nonlocal topology of the malonamide network, providing a basis for characterization of the structure and impact of polar solutes in increasingly complex organic phases. |
| Databáze: | OpenAIRE |
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