Current Research Topics:
As human population continues to grow, demands for clean water will increase, necessitating further development of water purification technologies. We utilize self-assembly as a route for producing mesoporous polymeric materials that can be used as ultrafiltration and nanofiltration membranes.
Phase Separation in Soft Matter
Phase separation in complex fluids such as polymers, surfactants, colloids, and biological materials plays a prominent role in determining morphology as well as mechanical, electrical, and transport properties due to pattern evolution in multicomponent mixtures of materials. We study phase separation in materials with potential applications in water purification membranes, batteries, and plastic recycling.
Dynamic phase diagram of PS/PVME blends, showing the types of phase separation occurring at each region: (A) normal NG, (B) SD, (C) transient gel induced VPS, (D) coalescence induced VPS, (E) aggregating NG, and (F) normal NG. Typical morphologies with phase separation time are shown next to the phase diagram. Mw,PS = 248 Kg/mol, Mn,PS = 87 Kg/mol, Tg,PS = 94 °C, Mw,PVME = 110 Kg/mol, Mn,PVME= 64 Kg/mol, Tg,PVME = -32 °C.
Self-Assembly of Surfactants and Block Copolymers
Surfactants and block copolymers self-assemble in different liquid crystalline structure in water/oil mixtures. We study such self-assembly through rheology and scattering.
Nanoemulsions have attractive features including long-term stability without going through coalescence, tunable flow behavior (from liquid to solid) and optical properties (from opaque to nearly transparent). One of the applications of nanoemulsions is to use them as templates for making mesoporous polymers. Nanoemulsion size, stability, and droplet-droplet interactions strongly depend on the nature of the surfactant used as a stabilizer. In this project, we want to follow by Small Angle Scattering (SAS) the structural, organizational changes and droplet-droplet interaction in nanoemulsions at the large window of volume fractions of the internal phase, starting below the glass transition to above the hexagonal close packing. After preparation of concentrated nanoemulsions, they will be polymerized by heating in isothermal condition at elevated temperatures. The long-term goal of this project is to construct a phase diagram (potential energy in terms of the volume fraction of the internal phase) to understand the ordering of nanoemulsions droplet for their potential use as templates.
Colloid and Interfacial Science
We perform research on emulsions and suspensions which have applications in food science and polymer synthesis.
Biopolymer Soil Amendments
We are investigating solutions to agricultural issues (e.g. soil erosion and water moisture content) using biodegradable polymers that occur naturally. We are applying current techniques and technologies to make economical and self-sustainable soil amendments.