Ryan D. Davis

Biography

Dr. Ryan D. Davis is an analytical/physical chemist at Sandia National Laboratories. His career has broadly focused on characterizing micro-materials and the processes occurring in confined micro-environments. As an undergraduate student at Colorado State University, he researched water confined in reverse micelles. At the University of California-San Diego, he performed research on gas-phase isotopic fractionation processes. For doctoral studies at the University of Colorado-Boulder, his research focused on salt crystal nucleation initiated at aerosol interfaces by particle collisions. As a postdoctoral fellow at Lawrence Berkeley National Lab, he studied accelerated chemical reactions in microdroplets.

His independent research career has spanned research topics such as aerosol supramolecular assembly, gas-surface interactions, and viral viability. Throughout his career he has developed and used a wide range of instrumental and analytical methods, including various single-particle levitation techniques, ambient-pressure mass spectrometry, micro-Raman spectroscopy, and many others. He has also taught introductory and advanced analytical chemistry courses at the university level. As part of the Analytical Research Lab at Sandia, he supports Sandia’s mission space through fundamental and applied long-term research projects as well as short-term measurements such as quantitative chemical analysis or identification of contaminants.

Research Interests

• Analytical & physical chemistry
• Mass spectrometry
• Gas-surface interactions
• Aerosol science
• Atmospheric chemistry
• Bioaerosols

Publications

• Schiffmann ZR, Fernanders MS, Davis RD, Tolbert MA (2023) Metal Oxide Particles as Atmospheric Nuclei: Exploring the Role of Metal Speciation in Heterogeneous Efflorescence and Ice Nucleation. ACS Earth Space Chem., DOI: 10.1021/acsearthspacechem.2c00370
• Humphrey B, Lobitz M, Hendricks A, Sanchez A, Storch S, Tezak M, Zenker J, Davis RD, Ricken B, Cahill J (2023) Viral Preservation with Protein-Supplemented Nebulizing Media in Aerosols. Applied Environ. Microbio. DOI: 10.1128/aem.01545-22
• Sheldon C, Choczynski J, Morton K, Palacios Diaz T, Davis RD, Davies JF (2023) Exploring the Hygroscopicity, Water Diffusivity, and Viscosity of Organic-Inorganic Aerosol – A Case Study on Internally-Mixed Citric Acid and Ammonium Sulfate Particles. Environ. Sci. Atmos., DOI: 10.1039/d2ea00116k
• Nieto-Caballero M, Davis RD, Villalba EF, Gomez OM, Huynh E, Handorean A, Ushijima S, Tolbert MA, Hernandez M (2022) Carbohydrate vitrification in microaerosolized saliva is associated with the humidity-dependent infectious potential of airborne coronavirus. PNAS Nexus, pgac301, DOI: 10.1093/pnasnexus/pgac301
• Huynh E, Olinger A, Woolley D, Kohli RK, Choczynski JM, Davies JF, Lin K, Marr LC, Davis RD* (2022) Evidence for a semisolid phase state of aerosols and droplets relevant to the airborne and surface survival of pathogens. Proc. Natl. Acad. Sci. USA, 119, e2109750119. DOI: 10.1073/pnas.2109750119
• Ushijima SB, Huynh E, Davis RD†, Tolbert MA (2021) Seeded Crystal Growth of Internally Mixed Organic−Inorganic Aerosols: Impact of Organic Phase State. J. Phys. Chem. A, 125, 8668-8679. DOI: 10.1021/acs.jpca.1c04471
• Richards DS, Trobaugh KL, Hajek-Herrera J, Price CL, Sheldon CS, Davies JF, Davis RD* (2020) Ion-Molecule Interactions Enable Unexpected Phase Transitions in Organic-Inorganic Aerosol. Science Advances, 6, eabb5643, DOI: 10.1126/sciadv.abb5643
• Richards DS, Trobaugh KL, Hajek-Herrera J, Davis RD* (2020) Dual-Balance Electrodynamic Trap as a Micro-Analytical Tool for Identifying Gel Transitions and Viscous Properties of Levitated Aerosol Particles. Analytical Chemistry. 92(4), 3086-3094. DOI: 10.1021/acs.analchem.9b04487
• Jacobs MI, Davis RD, Rapf RJ, Wilson KR (2019) Studying Chemistry in Micro-Compartments by Separating Droplet Generation from Ionization. Journal of the American Society of Mass Spectrometry, 30, 339-343. DOI: 10.1007/s13361-018-2091-y
• Ushijima SB, Davis RD, Tolbert MA (2018) Immersion and Contact Efflorescence Induced by Mineral Dust Particles. The Journal of Physical Chemistry A, 122, 1303-1311. DOI: 10.1021/ acs.jpca.7b12075
• Davis RD, Jacobs MI, Houle FA, Wilson KR (2017) Colliding-droplet microreactor: rapid on-demand inertial mixing and metal-catalyzed aqueous-phase oxidation processes. Analytical Chemistry 89(22): 12494-12501. DOI: 10.1021/acs.analchem.7b03601
• Jacobs MI, Davies JF, Lee L, Davis RD, Houle FA, Wilson KR (2017) Exploring chemistry in microcompartments using guided droplet collisions in a branched quadrupole trap coupled to a single droplet, paper spray mass spectrometer.  Analytical Chemistry 89(22): 12511-12519. DOI: 10.1021/ acs.analchem.7b03704
• Davis RD, Tolbert MA (2017) Crystal nucleation initiated by transient ion-surface interactions at aerosol interfaces. Science Advances 3(7):e1700425, DOI: 10.1126/sciadv. 1700425, advances.sciencemag.org/ content/3/7/e1700425
• Davis RD, Lance S, Gordon JA, Ushijima SB, Tolbert MA (2015) Contact efflorescence as a pathway for crystallization of atmospherically relevant particles.  Proceedings of the National Academy of Science 112(52):15815-15820, DOI: 10.1073/pnas.1522860113
• Davis RD, Lance S, Gordon JA, Tolbert MA (2015) Long working-distance optical trap for in situ analysis of contact-induced phase transformations. Analytical Chemistry 87:6186-6194, DOI: 10.1021/acs.anal chem.5b00809
• Nuding DL, Davis RD, Gough RV, Tolbert MA (2015) The aqueous stability of a Mars salt analog: Instant Mars. Journal of Geophysical Research – Planets 120:588-598, DOI: 10.1002/2014JE004722
• Nuding DL, Rivera-Valentin EG, Davis RD, Gough RV, Chevrier VF, Tolbert MA (2014) Deliquescence and efflorescence of Ca(ClO4)2: An investigation of stable aqueous solutions relevant to Mars. Icarus 243:420-428, DOI: 10.1016/j.icarus.2014.08.036
• Chakraborty S, Davis RD, Ahmed M, Jackson TL, Thiemens MH (2012) Oxygen isotope fractionation in the vacuum ultraviolet photodissociation of carbon monoxide: Wavelength, pressure and temperature dependency. The Journal of Chemical Physics 137:024309, DOI: 10.1063/1.4730911