Angelina Rogatch
MIT Department: Chemistry
Faculty Mentor: Prof. William Tisdale
Research Supervisor: Eliza K. Price
Undergraduate Institution: Bryn Mawr College
Hometown: Minsk, Belarus
Website: LinkedIn
Biography
Originally from Minsk, Belarus, Angelina Rogatch is a rising senior at Bryn Mawr College, majoring in Chemistry and Physics. In her A.B. thesis, advised by Sharon Burgmayer, Angelina studies the role of pyranopterin ligand in the bioinorganic catalysis of the molybdenum cofactor. As an MSRP 2023 intern, she worked with Timothy M. Swager, investigating the magneto-optical properties of polythiophenes. This summer, Angelina is exploring the surface chemistry of lead sulfide quantum dots under William A. Tisdale. As a former president of the Society of Physics Students, she strives to unite the scientific community by bringing together diverse perspectives to foster compassion, mutual support, and creativity. Angelina intends to pursue a Ph.D. in Chemical Engineering, aiming to work on designing organic electronic materials to meet the needs of emerging novel technologies. Outside of the lab, she can be found in a practice room, arranging music for violin or piano.
Abstract
Elucidating the Surface Chemistry of PbS Quantum Dots: Solution NMR Studies of the Organic Ligand Shell
Angelina Rogatch1, Eliza K. Price2, William A. Tisdale2
1Department of Chemistry and Physics, Bryn Mawr College,
2Department of Chemical Engineering, Massachusetts Institute of Technology
Colloidal quantum dots (QDs) are an emerging class of nanomaterials that exhibit size-
dependent, tunable optoelectronic properties that have been harnessed in display, laser,
bioimaging, and quantum information applications. A product of the Nobel Prize-winning
colloidal synthesis, QDs are composed of an inorganic, semiconducting core functionalized by an organic ligand shell. To expand the engineering control over QD properties, ligand
exchange techniques are actively being developed. However, a limited understanding of QD surface chemistry hinders efficient nanomaterial design and functionalization efforts.
Particular QDs of interest are lead sulfide (PbS), utilized in photovoltaic and sensing
applications due to their efficient infrared emission. To shed light on the surface chemistry of PbS QDs, this study investigates the effect of excess synthetic precursor (PbCl2) and ligand exchange methodology on PbS QD surface properties. We employ 1D proton nuclear magnetic resonance (NMR) and diffusion-ordered spectroscopy to probe ligand interactions in PbS QDs prepared with varying ligand exchange methods. Our results highlight the pivotal role of
excess PbCl2 in promoting efficient ligand exchange, particularly favoring ionic ligand pairs. Our findings advance the understanding of PbS surface chemistry, guiding the development of efficient ligand exchange techniques for tailored QD functionalization and realization of
advanced optoelectronic applications.
