VANAPALLI
LABORATORY
Building blocks such as polymer molecules, surfactants, colloidal particles, droplets and bubbles can be assembled to engineer a rich variety of complex fluids with unique microstructures. Understanding the interplay between fluid forces and microstructure of complex fluids is critical to their stability, processability and rheology. We employ microfluidic devices, imaging methods and computational fluid dynamics modeling to understand the flow dynamics of complex fluids. These fundamental insights are important for a wide range of applications including oil recovery, petrochemical processing, food & consumer products and lab-on-a-chip technologies. Research projects and our publications in this area are:
Droplet hydrodynamics in microfluidic devices
Microfluidic devices for rheological characterization
Elastic instabilities in polymer solutions
Nucleation and crystallization behavior of emulsions
Relevant publications
Gupta, S., Wang, W. S. and Vanapalli, S. A. Microfluidic viscometers for shear rheology of complex fluids and biofluids. Submitted, 2016.
Solomon, D. E., Raziq, A. and Vanapalli, S. A. A stress-controlled microfluidic shear viscometer based on smart-phone imaging. Rheologica Acta. Accepted, 2016.
Bithi, S. S and Vanapalli, S. A. Collective hydrodynamics of coalescing and non-coalescing drops in microfluidic parking networks. Soft Matter, 11, 5122-5132, 2015.
Wang, W. S. and Vanapalli, S.A. Millifluidics as a simple tool to optimize droplet networks: Case study on drop traffic in a bifurcated loop. Biomicrofluidics, 8, 064111, 2014.
Bithi, S. S, Wang, W. S., Blawzdziewicz, J. and Vanapalli, S. A. Coalescing drops in microfluidic parking networks: A multifunctional platform for drop-based microfluidics. Biomicrofluidics. 8, 034118, 2014.
Solomon, D. E. and Vanapalli, S. A. Multiplexed microfluidic viscometry for high throughput complex fluid rheology. Microfluidics and Nanofluidics. 16, 677-690, 2014.
Kim, J. and Vanapalli, S. A. Microfluidic production of spherical and non-spherical fat particles by thermal quenching of crystallizable oils. Langmuir. 29, 12307-12316, 2013.
Sun, M., Bithi, S. S. and Vanapalli, S. A. Microfluidic static droplet arrays with tuneable gradients in material composition. Lab on a Chip, 11, 3949-3952, 2011. (Cover Article)
Bithi, S. S. and Vanapalli, S. A. Behavior of a train of droplets in a fluidic network with hydrodynamic traps. Biomicrofluidics, 4, 044110, 2010. (Research Highlight).
Vanapalli, S. A., Banpurkar, A. G., van den Ende, D., Duits, M. H. G. and Mugele, F. Hydrodynamic resistance of single confined moving droplets in rectangular microchannels. Lab on a Chip, 9, 982-990, 2009.
Vanapalli, S. A., Ceccio, S. L. and Solomon M. J. Universal scaling for polymer chain scission in turbulence. Proceedings of the National Academy of Sciences USA, 103, 16660-16665, 2006 (Editorial Highlight).
Vanapalli, S. A., Islam, M. T. and Solomon M. J. Scission-induced bounds on maximum polymer drag reduction in turbulent flows. Physics of Fluids, 17, 095108, 2005.
Islam, M. T., Vanapalli, S.A. and Solomon M. J. Inertial effects on polymer chain scission in planar elongational cross-slot flow. Macromolecules, 37, 1023-1030, 2004.
Vanapalli, S. A., Palanuwech, J. and Coupland, J. N. Stability of emulsions to dispersed phase crystallization-effect of oil type, dispersed phase volume fraction and cooling rate. Colloids & Surfaces A: Physicochemcial and Engineering Aspects, 204, 227-237, 2002.
Vanapalli, S. A., Palanuwech, J. and Coupland, J. N. Influence of fat crystallization on the stability of flocculated emulsions. Joural of Agriculture and Food Chemistry, 50, 5224-5228, 2002.
Vanapalli, S. A. and Coupland, J. N. Emulsions under shear – formation of partially coalesced lipid structures. Food Hydrocolloids,15, 507-512, 2001.