Optical Fingerprinting of Dynamic Interfacial Reaction Pathways Using Liquid Crystals
Reactions at interfaces between fluid phases are widely used to synthesize small molecules, polymers, and nanoparticles. In situ monitoring of the underlying dynamic reaction pathways remains challenging. Liquid crystals (LCs) have been used to detect simple chemical transformations at interfaces in...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 39(2023), 5 vom: 07. Feb., Seite 1793-1803 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2023
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article |
| Zusammenfassung: | Reactions at interfaces between fluid phases are widely used to synthesize small molecules, polymers, and nanoparticles. In situ monitoring of the underlying dynamic reaction pathways remains challenging. Liquid crystals (LCs) have been used to detect simple chemical transformations at interfaces in situations where interface-bound reactants and products trigger distinct equilibrium orientations of LCs. However, whether or not LCs can be used to report complex reaction pathways via nonequilibrium states generated by reactions has not been explored. Here we explore this question using SN2' nucleophilic substitution reactions that involve a synthetic amphiphile and a series of amine-based nucleophiles with one to four reaction sites. Although all reactants and products generate the same equilibrium LC orientation, we find that each nucleophile defines a distinct set of possible reaction pathways with a characteristic spatial and temporal LC optical response unique to the nucleophile. Additional experiments reveal that the nonequilibrium orientational states of the LCs arise from a combination of dynamic interfacial processes that include adsorption/desorption of reactants, the presence of reaction intermediates on the LC interface, and the generation of interfacial tension gradients (Marangoni stresses). Overall, our results reveal that the spatiotemporal optical outputs of LCs ("optical fingerprints") can be a rich source of information regarding interfacial reactions |
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| Beschreibung: | Date Completed 07.02.2023 Date Revised 07.02.2023 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/acs.langmuir.2c02622 |