| AVS 64th International Symposium & Exhibition | |
| Applied Surface Science Division | Tuesday Sessions |
| Session AS+TF-TuA |
| Session: | Problem Solving Using Surface Analysis in the Industrial Laboratory |
| Presenter: | Juan Yao, Pacific Northwest National Laboratory |
| Authors: | J. Yao, Pacific Northwest National Laboratory D. Lao, Pacific Northwest National Laboratory X.F. Yu, Pacific Northwest National Laboratory S. Nune, Pacific Northwest National Laboratory D. Heldebrant, Pacific Northwest National Laboratory Z.H. Zhu, Pacific Northwest National Laboratory X.Y. Yu, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
Switchable ionic liquids (SWILs) are emerging green solvents in industry for cleaner separation and efficient biomass production, for instance. However, the liquid structure and composition of SWILs are not fully understood. Besides some off-line analyses using NMR and IR, our knowledge of the SWIL is quite limited. We used in situ liquid time-of-flight secondary ion mass spectrometry (ToF-SIMS) to study SWILs in this work. SWILs are introduced into a vacuum compatible microfluidic channel for analysis by liquid SIMS. Two model systems have been investigated. The first consists of 1, 8-diazabicycloundec-7-ene (DBU) and 1-hexanol with different CO2 loadings. The second is primarily made of koechanol with various CO2 loadings. Koechanol acts as both acid and base in the latter. Our results show two coexisting liquid phases in the two SWIL systems. This phenomenon was only hypothesized in previous theory prediction. We are able to provide the first physical evidence of the complex liquid-liquid interface using three-dimensional chemical mapping with submicrometer resolution. In addition, more complex stoichiometry is discovered as a result of SWIL formation. More importantly, we provide the first chemical spatial mapping elucidating the evolved liquid-liquid interface as a result of SWIL formation. We anticipate the more detailed molecular level understanding of the liquid structure and composition are instrumental to build the foundation for predicative material synthesis and more versatile industrial applications.