Nucleation and growth: models for faceted and layered materials

This dissertation presents the development of mechanistic models to describe the nucleation and growth kinetics of various nanoparticle systems. Nucleation and the subsequent growth processes govern the outcomes of nanoparticle formation; however, the kinetics are complicated because numerous processes, pathways, and components are involved. To address this, we integrate classical and nonclassical nucleation theories (CNT and NCNT) with thermodynamic and kinetic modeling tools to predict particle size distributions, nucleation rates, and yield. A phenomenological free energy model incorporating atomistic interactions and Becker–Döring theory is developed to describe the layer-by-layer growth of tetrahedral magic-sized clusters (MSCs), a class of semiconductor nanocrystals, which is poorly captured by traditional CNT model due to their non-spherical geometry and discrete growth. We also present population balance models for covalent organic frameworks (COFs), accounting for multilayer growth via a two-step nucleation process involving crystallization and polymerization. These models include analytical and numerical solutions that track monomer concentration, induction time, and yield as functions of time. The population balance approach incorporates templated nucleation and lateral growth for multilayer COF formation. Altogether, these models link molecular-scale interactions and thermodynamic driving forces with macroscopic synthesis outcomes, offering a quantitative framework for predicting and controlling nanoparticle properties such as size and aspect ratio. This work bridges experimental observations with predictive modeling, enabling the optimization of nanoparticle and COF synthesis for applications ranging from optoelectronics to membrane separations.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemical Engineering

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Weatherspoon, Howard Bernard

Contributors dc:contributor

• Peters, Baron
• Kenis, Paul
• Yang, Hong
• Statt, Antonia

• Nucleation and growth
• magic-sized clusters, covalent organic frameworks
• population balance equations

Statement dc:rights

• Copyright 2025 Howard Weatherspoon

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/129435

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F129435