Hallie Chelmo

Microscopic droplets are ubiquitous in the air, both indoors and outdoors. They are composed of chemically complex mixtures including water and co-dissolved salts, surfactants, and biological material. When we inhale these droplets, they grow in our lungs and may become vectors for communicable diseases, including viruses. As droplets persist in the air, they can act as seeds to grow cloud droplets, or nucleation points for ice crystallization of cloud particles. Their impacts on air quality in turn affect human and ecosystem health, climate, and weather. Although these impacts are large, there is a lack of rigorous treatment and quantification of their properties, which in turn leads to high uncertainty in global models. In addition to these environmentally relevant research areas, there are also numerous desirable applications harnessing the advantages of aerosols in additive manufacturing, sprays, drug-delivery, and nanoparticle synthesis.

Dr. Chelmo’s research aims to transform our fundamental understanding of aerosol surfaces and develop novel theoretical characterization methods and instrumentation. She previously developed aerosol surface tension models and measurements (PhD; University of Minnesota) and new measurements of individual levitated micro-droplets (Postdoc; Carnegie Mellon University). Here at UND, she leads the Aerosol Engineering Laboratory, where the Chelmo group uses laboratory experimental techniques and thermodynamic models to explore fascinating physicochemical processes of droplets in real-time.

Professor Chelmo started the Aerosol Engineering Laboratory in Fall 2019 after joining the mechanical engineering department at the University of North Dakota.

Boyer, H. C.; Gorkowski, K.; Sullivan, R. C., pH measurements of individual levitated microdroplets
using aerosol optical tweezers, Analytical Chemistry, 2020 92, 1089-1096

Boyer, H. C.; Dutcher, C.S., Atmospheric aqueous aerosol surface tension: isotherm-based modeling
and biphasic bicro uidic measurements, Journal of Physical Chemistry A, 121(25), 4733-4742, Feature
Article, 2017, doi: 10.1021/acs.jpca.7b03189

Boyer, H. C.;Bzdek, B.; Reid, J. P.; Dutcher, C. S., Statistical thermodynamic model for surface
tension of organic and inorganic aqueous mixtures, Journal of Physical Chemistry A, 2017, 121(1),
198-205. doi: 10.1021/acs.jpca.6b10057

Boyer, H. C.; Dutcher, C. S., Statistical thermodynamic model for surface tension of aqueous organic
acids with consideration of partial dissociation, Journal of Physical Chemistry A, 2016, 120(25), 4368-
4375. doi: 10.1021/acs.jpca.6b10057

Boyer, H. C.;Wexler, A.; Dutcher, C. S., Parameter interpretation and reduction for a unied statis-
tical mechanical surface tension model, Journal of Physical Chemistry Letters, 6(17), 3384-3389. doi:
10.1021/acs.jpclett.5b01346

CEM Dean's Research Award, 2019-2021

Invitee to Atmospheric Chemistry Colloquium for Emerging Senior Scientists (ACCESS XIV), 2017

NSF Graduate Research Fellowship, 2014-2017

Dreyfus Postdoctoral Fellow, Center for Atmospheric Particle Studies, Carnegie Mellon University, 2017-2019

Ph.D., Mechanical Engineering, University of Minnesota, 2012-2017

B.A. Physics, Honors, Macalester College, 2004-2008