Soft materials research
Soft materials such as polymers, colloids, surfactants, liquid crystals, and their composites comprise almost all materials of our everyday life. The examples include many consumer products, such as toothpaste, shaving cream, shampoo, lotion, etc. Life itself is an example of soft matter, as one famous scientist said "biology is just soft matter and ATP". Structurally, they have properties intermediate between simple liquids and crystalline solids - more ordered than liquids but more random than crystals. They are "delicate" in the sense that dramatic change of properties can result with the input of a very small energy. This is because the bonds, which hold them together, are weak and comparable to thermal energy. Therefore, we can assemble or disassemble many soft materials easily, resulting in many of their fascinating and useful properties.
In the recent years, research on these materials has become an exciting example of an emerging, interdisciplinary field of science drawing upon physicists, chemists, biologists, chemical engineers, and materials scientists. The goal of our laboratory is to conduct fundamental research in the field of soft matter. The current research projects include:
- Active and passive transport in complex crowded environments. We are interested in synthetic polymer systems as well as biological fluids, including mucus, serum, etc. These are characterized by multiple length-scales and time-scales and possess significant heterogeneities. The research has importance in understanding of intracellular transport, navigation of viruses and bacteria through the respiratory tract, and development of self-healing materials.
- Reconfigurable colloidal assembly at curved liquid-liquid interfaces. We investigate packing of particles onto a curved surface, evolution of topological defects during freezing and melting, and the effect of curvature on two-dimensional phase transition. These studies have applications in developing a new class of Pickering emulsions, curved photonic crystals, and novel anisotropic soft materials.
The students graduating from this group develop many sophisticated skills of interdisciplinary relevance, such as two-photon spectroscopy, microscopy, ellipsometry, Langmuir-Blodgett technique, particle tracking, image analysis, rheology, scattering techniques, ellipsometry, purification and characterization of samples, nanoparticle synthesis, functionalization, and their characterization, etc. It helps them to prepare well to explore a wide range of job opportunities in academia, industries, medical fields, and national laboratories.