Abstracts Book - IMRC 2018

• SD5-O023
A NEW FRAMEWORK FOR INTERPRETING CHEMICAL KINETICS OF
NANOCRYSTAL FORMATION BASED ON KINETIC DATA DERIVED
FROM LIQUID CELL ELECTRON MICROSCOPY
Taylor Woehl 1
1 University of Maryland, Chemical and Biomolecular Engineering, United States.
Rational purpose-built design of colloidal nanoparticles based on first principles
has remained elusive due to poor quantitative understanding of nanoparticle
formation mechanisms. One reason for this is the lack of suitable experimental
techniques that directly probe nanocrystal formation dynamics to reveal these
mechanisms. While recent liquid cell electron microscopy experiments have
unveiled semi-quantitative nanoparticle formation dynamics, a framework for
quantitatively interpreting these data based on first principles has not been
established. Here we introduce a new framework for quantitatively interpreting
the chemical kinetics of liquid phase nanoparticle formation by utilizing kinetic
data derived from liquid cell electron microscopy experiments. The framework
includes several components: 1) control over and numerical modeling of
radiolysis kinetics to systematically vary reactant concentrations, 2) extraction
of kinetic data from in situ movies using image segmentation and dimensional
reduction, 3) determination of a minimalist reaction kinetic mechanism for
nanoparticle formation, and 4) development of chemical reaction cascades to
interpret and model the time evolution of the particle size distribution. The
outcomes of applying this framework are the chemical kinetics of nanoparticle
formation, including rate laws for nucleation and growth, nucleation rate
constants, and particle-size dependent growth rate constants. In this talk, I will
demonstrate this framework for two model systems: silver nanoparticle growth
and simultaneous growth and assembly of colloidal platinum supraparticles. We
expect our new framework will enable quantitative interpretation and modeling
of the formation mechanisms of diverse types of colloidal nanocrystals,
including but not limited to, metallic, semiconductor, metal chalcogenide, and
hybrid organic/inorganic nanocrystals.
Acknowledgment:
T.J.W. acknowledges funding from University of Maryland start-up funds, the
University of Maryland Energy Research Center, and Oak Ridge Associated
Universities.