Non-Equilibrium and Dense Suspensions of Anisotropic Colloids
Fluids containing nano- to micrometer scale “colloidal” particles are found universally in nature and technology. Coatings, consumer products, filters, cosmetics, food, pharmaceuticals, and numerous industrial chemical processes all incorporate colloids. Although these applications are mature, there is a significant number of important questions that remain for these and next generation technologies that utilize colloids.
Our lab is particularly focused on colloids that are anisotropic, away from equilibrium, or in crowded environments, all of which are relevant to coatings, the production of multiphase materials, and the understanding of synthetic and biological active colloids. Our lab develops fundamental understanding for the fabrication, processing, probing, and utilization of these materials for use in applications.
Our tools are primarily in the measurement, prediction, and interpretation of the dynamic behavior of colloidal particles in response to neighbors, nearby surfaces, physiochemical or hydrodynamic cures. Our focus has been on anisotropic (e.g. non-spherical, non-uniform surface chemistry) particles because of the technological relevance of such particles, including clay, yeast, red blood cells, and carbon nanoparticles. We often study these systems away from equilibrium, for instance in response to an external electric field. More recently, we moved towards non-equilibrium active colloidal system where motion is generated by the particle itself. We further extended this focus on non-equilibrium behavior in complex fluids to dynamic systems
Scattering Morphology Resolved Total Internal Reflection Microscopy (SMR-TIRM) of Colloidal Spheres. J Yan, D Efremenko, AA Vasilyeva, A Doicu, T Wriedt, and CL Wirth, accepted in Computational Mathematics and Modeling (2021): 1-8.
DLVO Energy Landscape of a Janus Colloid with a Non-Uniform Cap Thickness, S Rajupet, A Rashidi, and CL Wirth, Physical Review E (2021) 103, 032610
Influence of PEG on the clustering of active Janus colloids. M Kalil, NR Baumgartner, MW Issa, SD Ryan, and CL Wirth, arXiv, 2021, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 627:127191
Developing scattering morphology resolved Total Internal Reflection Microscopy (SMR-TIRM) for orientation detection of colloidal ellipsoids. A Rashidi, S Domínguez-Medina, J Yan, DS Efremenko, AA Vasilyeva, A Doicu, T Wriedt, CL Wirth, Langmuir (2020) 36, 43, 13041–13050
Single and ensemble response of colloidal ellipsoids to a nearby ac electrode. J Yan, A Rashidi, CL Wirth, Colloids and Surfaces A: Physicochemical and Engineering Aspects (2020), 606:125384
Efficient Sizing of Single Layer Graphene Oxide with Optical Microscopy under Ambient Conditions. Q Luo, CL Wirth, and E Pentzer. Carbon (2020) 157, 395-401
Charged Nanoparticles Quench the Propulsion of Active Janus Colloids. MW Issa, NR Baumgartner, MA Kalil, SD Ryan, and CL Wirth. ACS Omega, 2019
Influence of cap weight on the motion of a Janus particle very near a wall. A Rashidi, S Razavi, and CL Wirth, arXiv, 2019, Physical Review E (2020) 101, 042606
Purification and Assembly of DNA-Stabilized Boron Nitride Nanotubes into Aligned Films. VR Kode, ME Thompson, C McDonald, J Weicherding, T Dobrila, PS Fodor, CL Wirth, and G Ao, ACS Applied Nano Materials (2019) 2, 4, 2099–2105
A light scattering model for total internal reflection microscopy of geometrically anisotropic particles. A Doicu, AA Vasilyeva, DS Efremenko, CL Wirth, and T Wriedt, Journal of Modern Optics (2019) 1–13
Local measurement of Janus particle cap thickness. A Rashidi, MW Issa, I Martin, A Avishai, S Razavi, and CL Wirth, ACS Applied Materials and Interfaces (2018) 10, 37, 30925 – 30929