New Insights into χ(3) Measurements: Comparing Nonresonant Second Harmonic Generation and Resonant Sum Frequency Generation at the Silica/Aqueous Electrolyte Interface
| dc.contributor.author | Rehl, Benjamin | |
| dc.contributor.author | Rashwan, Mokhtar | |
| dc.contributor.author | DeWalt-Kerian, Emma L. | |
| dc.contributor.author | Jarisz, Tasha A. | |
| dc.contributor.author | Darlington, Akemi M. | |
| dc.contributor.author | Hore, Dennis K. | |
| dc.contributor.author | Gibbs, Julianne M. | |
| dc.date.accessioned | 2019-12-23T23:39:27Z | |
| dc.date.available | 2019-12-23T23:39:27Z | |
| dc.date.copyright | 2019 | en_US |
| dc.date.issued | 2019 | |
| dc.description.abstract | Historically, different pH-dependent behaviors at the mineral oxide/aqueous electrolyte interface have been observed by nonresonant second harmonic generation (SHG) and resonant sum frequency generation (SFG), despite a general understanding that both techniques are dominated by the response of water. Here, we compare the two at the silica/aqueous interface at high salt concentration and as a function of pH to shed light on the origins of both measurements. From this comparison and SHG measurements at the silica/air interface, we conclude that SHG originates from the net order of water and the silica substrate, with the latter dominating the observed intensities below pH 6.5. In contrast, SFG is dominated by the higher SF activity, yet a lower number density, of waters that contribute to the low-wavenumber range, according to molecular dynamic simulations. Furthermore, spectral resolution in SFG of oppositely oriented water populations prevents the cancellation of signal, making it more difficult to relate SF intensity to the net order of water. | en_US |
| dc.description.reviewstatus | Reviewed | en_US |
| dc.description.scholarlevel | Faculty | en_US |
| dc.description.sponsorship | J.M.G. gratefully acknowledges the Natural Sciences and Engineering Research Council of Canada for an Accelerator Award, the Alfred P. Sloan Foundation for a Research Fellowship, and Petro-Canada for a Young Innovator Award. B.R. gratefully acknowledges support from the Alberta/Technical University of Munich International Graduate School for Hybrid Functional Materials (ATUMS-NSERC CREATE) program, the University of Alberta Future Energy Systems, and the Queen Elizabeth II Graduate Scholarship. B.R. and T.A.J. gratefully acknowledge the Natural Sciences and Engineering Research Council of Canada for a Canada Graduate Scholarship. Molecular dynamics simulations were run on WestGrid clusters. Belaid Moa (University of Victoria, WestGrid, Compute Canada) provided valuable assistance with the resource allocation and troubleshooting to run our simulations. | en_US |
| dc.identifier.citation | Rehl, B.; Rashwan, M.; DeWalt-Kerian, E. L.; Jarisz, T. A.; Darlinton, A. M.; Hore, D. K.; & Gibbs, J. M. (2019). New insights into χ(3) measurements: Comparing nonresonant second harmonic generation and resonant sum frequency generation at silica/aqueous electrolyte interface. The Journal of Physical Chemistry C, 123(17), 10991-11000. DOI: 10.1021/acs.jpcc.9b01300 | en_US |
| dc.identifier.uri | https://doi.org/10.1021/acs.jpcc.9b01300 | |
| dc.identifier.uri | http://hdl.handle.net/1828/11416 | |
| dc.language.iso | en | en_US |
| dc.publisher | The Journal of Physical Chemistry C | en_US |
| dc.subject | Interfaces | en_US |
| dc.subject | Nonlinear optics | en_US |
| dc.subject | Silica | en_US |
| dc.subject | Molecules Polarization | en_US |
| dc.title | New Insights into χ(3) Measurements: Comparing Nonresonant Second Harmonic Generation and Resonant Sum Frequency Generation at the Silica/Aqueous Electrolyte Interface | en_US |
| dc.type | Postprint | en_US |