Our research aims to understand transport properties of nanoparticles within polymer and biopolymer solutions, gels, and melts. Our research has identified the effects of hydrodynamic & excluded volume interactions, depletion of polymer near particle surface, polymer segmental motion, and activated hopping, which are operative for different particle size regimes and polymer concentration. We primarily use two-photon fluctuation correlation spectroscopy and rheology for this research. A current project is to investigate how nanoparticles diffuse though more complex biopolymer network, such as mucus, where many of the above mentioned effects are present simultaneously.

Another ongoing research is to dynamically control assembly of colloidal particles interacting through long range correlation near a continuous phase transition. We can manipulate locally and reversibly both colloidal interaction and their concentration through temperature and temperature gradient. The primary method employed is confocal microscopy. A current project is to understand the packing, crystallography, and defect physics of anisotropic particles, including discoids and ellipsoids onto a curved liquid-liquid interface.