My research projects
Graduate research
Laser cooling
Principal investigator: Professor Lan Cheng
Physicists can use lasers to cool down atoms and molecules to near
absolute zero, which makes them easier to study. Compared to atoms
and diatomic molecules, polyatomic molecules are much more difficult
to cool because of their additional vibrational degrees of freedom.
But polyatomic molecules are a promising option for precision
measurement, and it has been proposed that they could play a vital
role in the search for physics beyond the Standard Model. I am
constructing potential energy surface fits for these polyatomic
molecules, which can then be used to figure out how the laser
cooling can be performed.
Light-induced conical intersections
Principal investigator: Professor David R. Yarkony (deceased)
A conical intersection is a geometric orientation where two
electronic states of a molecule have the same energy. They are
important in photochemistry because they allow molecules to quickly
lose electronic energy, and they play a vital role in human vision,
DNA photoprotection, and photosynthesis. In 1995, it
was said
that "Ever since the development of the laser, the quest to use
light to control the future of matter has been one of the Holy
Grails of chemistry". Light–matter interactions can give rise to
light-induced conical intersections (LICIs) by reshaping the
potential energy surfaces. For this project, I studied how LICIs
affect the photodissociation of ammonia. A Floquet Hamiltonian was
used to implement the light interaction, and quantum chemical data
was provided by diabatic potential energy, nonadiabatic coupling,
dipole, and spin–orbit coupling matrix surfaces fitted using neural
networks.
Presented at the
29th Dynamics of Molecular Collisions Conference
Published in
The Journal of Physical Chemistry Letters
Presented at the
2024 Molecular Interactions and Dynamics Gordon Research
Conference
Photoelectron spectroscopy simulation
Principal investigator: Professor David R. Yarkony (deceased)
Anion ultraviolet photoelectron spectroscopy is a helpful tool that
can provide a great deal of insight into the vibrational behavior of
molecules. Usually, it is relatively easy to simulate a molecule's
spectrum: just calculate the Franck–Condon overlaps. But this all
falls apart for tetrazolyl (and other azolyls) because its lowest
electronic states cross (a conical intersection). More advanced
techniques are needed that treat the interactions between electronic
states, and I used one such approach to study tetrazolyl. This
molecule's complex and difficult-to-calculate electronic structure
necessitated the use of a potential energy matrix model with
fourth-order terms. Other azolyls were previously studied using only
second-order parameters without issue.
Published in
The Journal of Chemical Physics
Presented at the
28th Dynamics of Molecular Collisions Conference
Undergraduate research
Microscopy, elemental mapping, and calorimetry of metal-infused aerogels
Advisor: Professor Mary K. Carroll (2024 ACS president)
Automotive catalytic converters contain platinum-group metals, but
mining them is environmentally destructive. Metal-containing
aerogels are a promising alternative thanks to their unique
properties including high specific surface area and heat resistance.
I synthesized metal-infused aerogels using a hydraulic hot press
with a patented rapid supercritical extraction method. I
characterized nanostructure with scanning electron microscopy (SEM),
energy-dispersive X-ray spectroscopy (EDS), powder X-ray diffraction
(XRD), atomic force microscopy (AFM), and differential scanning
calorimetry (DSC), all of which I operated myself. With conventional
protocols, SEM is nearly impossible on aerogels because they are so
insulating, and AFM is difficult because aerogels are so soft. I
developed and implemented novel sample preparation techniques that
enabled nanometer-resolution microscopy of these tricky materials.
Published in the
Journal of Sol-Gel Science and Technology
Published in the
Journal of Sol-Gel Science and Technology
Presented at the 31st Steinmetz Symposium
▶ Video
Presented at the
ACS Spring 2021 National Meeting
Published in
Emission Control Science and Technology
Presented at the
30th Steinmetz Symposium
Published in the
Journal of Sol-Gel Science and Technology
Presented at the 2019 New York Six Undergraduate Research
Conference
Presented at the 2019 ACS Northeast Regional Meeting
Presented at the
29th Steinmetz Symposium
Acknowledged in a publication in The
Journal of Visualized Experiments
Acknowledged in a publication in
The Journal of Supercritical Fluids
Liquid-liquid interfacial assembly of peptoid nanosheets
Advisor: Professor Ellen Robertson
Gold nanoparticles exhibit localized surface plasmon resonance
(LSPR), which changes their color depending on their environment and
how close they are to each other. This is promising for sensing
applications, including the detection of environmental toxins. I
synthesized peptoid monolayer sheets containing gold nanoparticles
and used UV–Vis spectroscopy to assess LSPR activity.
Presented at the
ACS Spring 2022 National Meeting
Published in
Chemical Communications
Presented at the
30th Steinmetz Symposium
Presented at the
259th ACS National Meeting
Calculating surface tension with capillary waves
Advisor: Professor Jef Wagner
I constructed an experimental apparatus to measure the surface
tension coefficient of liquids. A wave-generating motor produced
capillary waves on the surface of the sample liquid. To make the
measurement, image tracking software was used to examine the
dispersion relationship of the generated waves. Unlike some other
experimental setups, ours can work on any fluid regardless of
polarity.
Presented at the
29th Steinmetz Symposium
Interactive Physical and Cognitive Exercise System
Advisor: Professor Cay Anderson-Hanley
I contributed to a neuropsychological study on the effect of
exercise combined with puzzle games (neuro-exergaming) on cognitive
health and wellness, including for patients coping with Alzheimer's
and other challenges.
Acknowledged in a publication in
Frontiers in Aging Neuroscience
Acknowledged in a publication in
Clinical Interventions in Aging
Quantum chemistry PhD researcher
Johns Hopkins University
Baltimore, MD