Surface-Induced Crystallization of Sodium Dodecyl Sulfate (SDS) Micellar Solutions in Confinement
| Autor: | João T. Cabral, Sepideh Khodaparast, Gunjan Tyagi, William N. Sharratt, Julius Marcos |
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| Rok vydání: | 2020 |
| Předmět: |
Technology
Materials science Chemistry Multidisciplinary Materials Science Nucleation Analytical chemistry Materials Science Multidisciplinary Surface finish law.invention Dynamic light scattering law HETEROGENEOUS NUCLEATION Electrochemistry Surface roughness NANOPARTICLES WATER-SYSTEM General Materials Science CRYSTAL-STRUCTURE Crystallization TEMPERATURE Spectroscopy Science & Technology Chemical Physics Chemistry Physical PHASE-DIAGRAM Surfaces and Interfaces FREE-ENERGY Condensed Matter Physics Small-angle neutron scattering Surface energy Chemistry Micellar solutions Physical Sciences GROWTH SHAPE |
| Zdroj: | Langmuir : the ACS journal of surfaces and colloids. 37(1) |
| ISSN: | 1520-5827 0743-7463 |
| Popis: | We investigate the role of confinement on the onset of crystallization in subcooled micellar solutions of sodium dodecyl sulfate (SDS), examining the impact of sample volume, substrate surface energy, and surface roughness. Using small angle neutron scattering (SANS) and dynamic light scattering (DLS), we measure the crystallization temperature upon cooling and the metastable zone width (MSZW) for bulk 10–30 wt% SDS solutions. We then introduce a microdroplet approach to quantify the impact of surface free energy (18–65 mN/m) and substrate roughness (Rα ≃ 0–60 μm) on the kinetics of surface-induced crystallization through measurements of induction time (ti) under isothermal conditions. While ti is found to decrease exponentially with decreasing temperature (increasing subcooling) for all tested surfaces, increasing the surface energy could cause a significant further reduction of up to ∼40 fold. For substrates with the lowest surface energy and longest ti, microscale surface roughness is found to enhance crystal nucleation, in particular for Rα ≥ 10 μm. Finally, we demonstrate that tuning the surface energy and microscopic roughness can be effective routes to promote or delay nucleation in bulk-like volumes, thus greatly impacting the stability of surfactant solutions at lower temperatures. |
| Databáze: | OpenAIRE |
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