Surfaces and Complex Fluids

We are broadly interested in the transport of complex fluids (suspensions of polymers, colloids, nanoparticles, bacteria, bacteriophages, and/or proteins) near surfaces that confine, crowd, or support them. This broad class of problems is scientifically fascinating: both the chemical and mechanical properties of surfaces can influence behaviors such as adhesion, diffusion, and motility.

Microbiology Near Surfaces

Pseudomonas
			  aeruginosa bacteria

We use microfabrication and microscopy to investigate how bacteria move on, interact with, and adhere to surfaces prior to formation of bacterial biofilms. We are working with Megan Robertson (UH ChBE) to prepare polymer substrates that modify bacterial motility and adhesion and with Patrick Cirino (UH ChBE) to engineer bacterial motility. We collaborate externally with Arezoo Ardekani (Purdue), Douglas Bartlett (UCSD/Scripps), and Roseanne Ford (Virginia) to understand the role of motility on biodegradation.

Applications of this work include medical diagnostics, antifouling materials, and bioremediation.

Colloids in Confinement and in Flow

Binary colloidal alloy

We use confocal microscopy and bulk rheology to investigate the relationship between structure and mechanical properties for ordered (crystalline) and disordered (gels, glasses) colloidal suspensions during microchannel flow. We are working with Jeremy Palmer (UH ChBE) to develop simulations.

Applications for this work include materials for direct-write assembly and oil extraction and production.

Nanoparticles in Transport

Nanoparticles in solution

We use microfabrication and microscopy to investigate the transport properties of nanoparticles in model porous media and in non-Newtonian fluids (with Ramanan Krishnamoorti, UH ChBE).

Applications for this work include enhanced oil recovery, drug delivery, and nanocomposite processing.

Diagnostics for Public Health

Bacteriophage on a slide

We use microfluidics and particle-tracking to develop assays to detect proteins, viruses, and bacteria (with Richard Willson, UH ChBE).

Applications for this work include ultrasensitive diagnostics for bioterrorism and public health.

Protein Nucleation in Shear Flows

Protein clusters visualized
		     with differential dynamic microscopy

We use microscopy and microfluidics to investigate the role of shear flows on protein nucleation (with Peter Vekilov, UH ChBE).

Applications for this work include pharmaceuticals and drug delivery.

Other problems

Your problem here!

We love to collaborate! We have expertise in particle tracking; brightfield, fluorescence, and confocal microscopy; dynamic and static light scattering; microfabrication and soft lithography; and rheology.

If you're interested in talking, contact us!

Recent Publications

Polydisperse Mie model

Differential dynamic microscopy is sensitive to particle polydispersity. See Safari, Vorontsova, Poling-Skutvik, Vekilov, and Conrad, Phys. Rev. E (2015) for more information.

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