The common theme of our research group, Complex Fluids Laboratory, is to understand the flow behavior of complex fluids; examples include foams, emulsions and fluids containing nanoparticles of different sizes, shapes, surface chemistry, and flexibility. The ultimate goal is to develop novel, scalable techniques for processing complex fluids into multifunctional, high performance articles (e.g., films, fibers, and polymer composites). We are particularly interested in the following areas:
Inkjet printing has evolved from a graphic printing technology to become a fabrication technology, capable of depositing a wide range of materials onto different substrates to produce flexible electronics and 3-D objects. We aim to improve the reliability and push the resolution limit of inkjet printing to the sub-micron range. The findings may expedite the development of flexible electronics for solar cells, cell phones, cameras, and e-book readers. Another promising application relates to the medical field. Sensors, for example, can be printed on the skin as a “tattoo” to monitor the health of patients. Similarly, skin grafts may also be printed to accelerate healing in the case of burn and extensive wounds.
A key challenge in realizing the full potential of nanoparticles is the control of their spatial distribution during processing and application. To overcome this challenge, we focus on understanding:
Of particular interest are: 1) the effect of confinement on the assembly of nanoparticles, 2) flow through porous media (e.g., nanoparticle distribution during resin infusion), and 3) the creation of multifunctional metamaterials.
In oil recovery, stranded oil is oil that cannot be recovered by primary or secondary means. This type of oil is trapped by viscous, capillary, and interfacial forces within the pores in rock formation and accounts for about two-thirds of the original oil in place (~400 billion barrels in the US alone). Enhanced oil recovery (EOR), also known as tertiary recovery, focuses on modifying fluid flow to improve oil displacement in the reservoir. Our vision is to develop next generation EOR technology using nanoparticle-stabilized foams and emulsions. To this end, we need to understand the microstructure and interfacial rheology of nanoparticle-decorated interfaces.