Mason, Thomas G.

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Joint Appointment in UCLA Physics Department. California NanoSystems Institute

Contact Information

Young Hall 3040
(310) 206-0828
Young Hall 2107
(310) 206-0292

Short Biography

Prof.  Mason received B.S. dual degrees in physics with high honors and electrical engineering summa cum laude from the University of Maryland- College Park in 1989. Supported by an NSF graduate fellowship, he studied soft condensed matter physics at Princeton University and earned his Ph.D. in physics in 1995. His dissertation work explained the onset of elasticity as dispersions of solid spheres and liquid droplets are concentrated to form colloidal glasses, and he also created a technique, thermal "passive" microrheology, that is now widely used.

His first postdoctoral position was at the Centre de Recherche Paul Pascal (CNRS) in Bordeaux, France, where he explored the complex structure-flow-composition interplay in emulsification, and he spent an additional postdoctoral year doing research in chemical and bio-engineering on biopolymer microrheology, including on DNA and F-actin, at Johns Hopkins University. As a staff scientist and PI at ExxonMobil Research and Engineering, starting in 1997, he led research in light and small angle neutron scattering from asphaltenes in hydrocarbon systems involving heavy oils, resulting in two US patents and an internal commercialization that improved refinery productivity.

Joining UCLA in 2003 as an assistant professor of chemistry and of physics, he advanced to full professor in both departments in 2009. Prof. Mason's interdisciplinary research group of chemists and physicists is now working on directing assembly of custom-shaped lithographic particles as molecular mimics, fabricating complex nanoemulsions via non-equilibrium routes, modeling microrheology and aggregation, and exploring biopolymer-colloid interactions in electrophoresis. Prof. Mason has over 100 publications in peer-reviewed journals, including Nature, Science, PNAS, PRL, and JACS, and 10 issued US patents, 8 of which are based on research at UCLA. He is a fellow and life member of the American Physical Society, and he is a recipient of an NSF Career Award.

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Research Interest

Microrheology is the study of the deformation and flow of complex fluids at the microscale. As a graduate student, T.G. Mason invented an approach in 1993 for deducing local and macroscopic viscoelastic shear moduli of complex fluids by measuring the thermal fluctuations of colloidal particles introduced as probes. This approach, later published in Physical Review Letters in 1995 with his advisor D.A. Weitz (PRL 74 1250), sparked the modern field of microrheology. We continue research on glasses using thermal microrheology; our group also uses laser tweezers to manipulate dielectric probe microparticles such as polystyrene spheres and wax disks in order to investigate non-linear rheological properties.

  • Microrheology: measuring the dynamic mechanical shear properties of viscoelastic soft materials over an extraordinarily large range of time scales by optically observing the diffusive motion of micron-sized probe particles embedded in these materials
  • Shear-induced structures in complex fluids: emulsification, shear-banding, shear-ordering
  • Neutron and light scattering from nanomaterials: asphaltenes, clays, droplets, polymers
  • Directed assembly of nanoparticles in solution using shape-dependent attractive interactions
  • Free boundary flows in microfluidic devices
  • Structure and dynamics of soft colloidal glasses


Honors & Awards

  • Fellow of the American Physical Society
  • NSF CAREER Award
  • Herbert Newby McCoy Award for Research Excellence
  • American Physical Society DFD Gallery of Fluid Motion Award
  • Princeton Joseph Henry Prize in Physics
  • Glenn T. Seaborg Award
  • Intel New Faculty Award
  • Exxon Graduate Research Fellow
  • NSF Graduate Research Fellow


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Other Selected Publications

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