Cryogenic Transmission Electron Tomography (Cryo-ET): Developed Cryo-ET methods as quantitative thermodynamic tools. Studied interaction potentials and other thermodynamic properties of nanoparticles and proteins. Key publications:
 

Analytical Ultracentrifugation (AUC): Designed and implemented a novel AUC capillary cell tailored for probing solution properties of dispersions (nanoparticles, proteins, polymers) under high concentration regimes (awarded the Svedberg First Poster Prize at the AUC-2024 conference). Combined multiple AUC techniques for analysis of semiconductor nanocrystals so as to improve their synthesis. Established thermodynamic equilibrium methods to study nanoscale particles. Provided service to industrial partners in therapeutic material characterization. Key publications include:
 

Nanoparticle Characterization via STM: Developed high-resolution imaging parameters for scanning tunneling microscopy (STM) of gold nanoparticles, facilitating the high-resolution visualization of organic ligand shells. Designed an STM liquid cell, enabling nanoparticle imaging in high-boiling liquids, significantly improving contrast and stability of nanoparticle STM imaging. Created analytical simulations of STM imaging to distinguish artifacts from genuine image features. key publications  include:

 

Magnetic Nanoparticles: Synthesized and characterized core-shell magnetic nanoparticles. Characterized nanoparticles using high-resolution TEM and electron energy loss spectroscopy (EELS). Studied intra-particle magnetic interactions. Key publications:

o Ong Q. et al. Physical Review B, 2009

o Ong Q. et al. Journal of Physical Chemistry C, 2011

Colloidal Interactions via AFM: Coated atomic force microscopy (AFM) tips with nanoparticles to measure colloidal interaction forces between nanoparticles and surfaces. Key publications:

o Ong Q. et al. Journal of Colloid and Interface Science, 2007

o Sokolov I., Ong Q. et al. Journal of Colloid and Interface Science, 2006