Tom Haxton

Postdoctoral Fellow
Theory of Nanostructured Materials Facility
[email protected]
LinkedIn
GitHub
Google Scholar

Ph. D., Physics, University of Pennsylvania (2010)
S. B., Mathematics and Physics, University of Chicago (2004)


Research Interests

My research focuses on developing design rules for the self-assembly of or directed assembly of molecular building blocks into hierarchically structured materials, using a combination of statistical mechanical theory, coarse-grained and multi-scale modeling, and experimental collaborations.

Inspired by recent and ongoing experiments at the Molecular Foundry, Steve Whitelam and I developed a set of design rules for the efficient self-assembly of a model porous crystal, demonstrating two main results. First, the assembly of anisotropic components into porous structures follows very different design principles than the assembly of isotropic components into close-packed structures. Second, the optimal assembly of hierarchical structures does not necessary follow hierarchical assembly pathways.

In a Molecular Foundry collaboration with Ron Zuckermann and his lab, we have combined physical chemical, scattering, imaging, and computational approaches to understand and control the hierarchical self-assembly of peptoid polymers (synthetic isomers of peptides) into solid, free-floating bilayer nanosheets. We have discovered microscopic mechanisms by which this unique material sequentially assembles through adsorption, compression, and collapse at an air-water interface.

Publications

  • R. V. Mannige, T. K. Haxton, C. Proulx, G. L. Butterfoss, R. N. Zuckermann, and S. Whitelam, “Novel secondary structure of biomimetic polymers enables extended two-dimensional assemblies,” submitted.
  • T. K. Haxton, “High-resolution coarse-grained modeling using oriented coarse-grained sites,” J. Chem. Theory Comput. 11, 1244 (2015).
  • T. K. Haxton, R. V. Mannige, R. N. Zuckermann, and S. Whitelam, “Modeling sequence-specific polymers using anisotropic coarse-grained sites allows quantitative comparison with experiment,” J. Chem. Theory Comput. 11, 303 (2015).
  • B. Rad, T. K. Haxton, A. Shon, S.-H. Shin, S. Whitelam, and C. M. Ajo-Franklin, “Ion-specific control of the self-assembly dynamics of a nanostructured protein lattice,” ACS Nano 9, 180 (2015).
  • B. Sanii, T. K. Haxton, G. K. Olivier, A. Cho, B. Barton, C. Proulx, S. Whitelam, and R. N. Zuckermann, “Structure-determining step in the hierarchical assembly of peptoid nanosheets,” ACS Nano 8, 11674 (2014).
  • S. Whitelam, I. Tamblyn, T. K. Haxton, M. B. Wieland, N. R. Champness, J. P. Garrahan, and P. H. Beton, “Common physical framework explains phase behavior and dynamics of atomic, molecular, and polymeric network-formers,” Phys. Rev. X 4, 011044 (2014).
  • T. K. Haxton, H. Zhou, I. Tamblyn, D. Eom, Z. Hu, J. B. Neaton, T. F. Heinz, and S. Whitelam, “Competing thermodynamic and dynamic factors select molecular assemblies on a gold surface,” Phys. Rev. Lett. 111, 265701 (2013).
  • T. K. Haxton and S. Whitelam, “Do hierarchical structures assemble best via hierarchical pathways?,” Soft Matter 9, 6851 (2013).
  • L. J. Daniels, T. K. Haxton, N. Xu, A. J. Liu, and D. J. Durian, “Temperature-pressure scaling for air-fluidized grains on approaches to Point J,” Phys. Rev. Lett. 108, 138001 (2012).
  • T. K. Haxton and S. Whitelam, “Design rules for the self-assembly of a protein crystal,” Soft Matter 8, 011503 (2012).
  • T. K. Haxton, “Ratio of effective temperature to pressure controls the mobility of sheared hard spheres,” Phys. Rev. E 85, 011503 (2012).
  • M. Schmiedeberg, T. K. Haxton, S. R. Nagel, and A. J. Liu, “Mapping the glassy dynamics of soft spheres onto hard-sphere behavior,” EPL 96, 36010 (2011).
  • T. K. Haxton, M. Schmiedeberg, and A. J. Liu, “Universal jamming phase diagram in the hard-sphere limit,” Phys. Rev. E 83, 031503 (2011).
  • T. K. Haxton and A. J. Liu, “Kinetic heterogeneities at dynamical crossovers,” EPL 90, 6604 (2010).
  • N. Xu, T. K. Haxton, A. J. Liu, and S. R. Nagel, “Equivalence of glass transition and colloidal glass transition in the hard-sphere limit,” Phys. Rev. Lett. 103, 245701 (2009). Editor's suggestion. Physics synopsis
  • T. K. Haxton and A. J. Liu, “Activated dynamics and effective temperature in a steady state sheared glass,” Phys. Rev. Lett. 99, 195701 (2007).