Organic Ligands and Colloidal Nanocrystal Surface Thermodynamics
As materials approach the nanoscale, they begin to exhibit size dependent properties. In particular, a larger fraction of atoms that make up the whole of the material are located on the material’s surface. Colloidal nanocrystals are commonly synthesized where their surfaces are terminated by organic molecules, often referred to as ligands. In this talk, I will present the work that I have done during my graduate studies on understanding the thermodynamics of the surfaces of colloidal nanocrystals and reactions that occur on their surfaces. In particular, collective effects originating from long aliphatic carbon chains that make up an organic ligand shell will be discussed and their effect on reaction thermodynamics and the structure of the organic ligand shell. Additionally, tight binding groups at the organic/inorganic interface affect the surface energy of these nanocrystals. Using calorimetry, we have measured a negative surface in many semiconductor nanocrystals, and implications of these measurements will be discussed.
Jason Calvin is a graduate student at the University of California, Berkeley in the Department of Chemistry where he works in Dr. Paul Alivisatos lab studying nanocrystal thermodynamics.
He received his B.S. degree from Brigham Young University in Chemistry in 2018 where he worked with Dr. Brian Woodfield studying low temperature heat capacities of materials.
Jason’s current research utilizes traditional calorimetry techniques to study the thermodynamics of small systems and to probe how the surface chemistry of nanocrystals can inform their properties and stability.
Jason will be graduating this semester and has accepted a position to work in Dr. Jarad Mason’s lab at Harvard University as a postdoctoral researcher this fall.