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Athanassios Panagiotopoulos

Athanassios Z. Panagiotopoulos

Susan Dod Brown Professor of Chemical and Biological Engineering

Dipl. Eng., National Technical University of Athens, 1982
Ph.D., Massachusetts Institute of Technology, 1986
Postdoctoral Scholar, University of Oxford, 1986-87

Room: A317 Engineering Quad
Phone: 609-258-4591
Email: azp@princeton.edu

Webpage: Panagiotopoulos Group

Honors and Awards

  • American Academy of Arts and Sciences, 2012
  • National Academy of Engineering, 2004
  • J.M. Prausnitz Award in Applied Chemical Thermodynamics, 1998
  • Allan P. Colburn Award, American Institute of Chemical Engineers, 1995
  • Teacher-Scholar Award, Camille and Henry Dreyfus Foundation, 1992
  • Presidential Young Investigator, National Science Foundation, 1989

Concurrent University Appointments

  • Affiliated Faculty, Princeton Institute for the Science and Technology of Materials

Publications

Research Areas

Research Interests

Research in our group focuses on development and application of theoretical and computer simulation techniques for the study of properties of fluids and materials. Emphasis is on molecular-based models that explicitly represent the main interactions among microscopic constituents of a system. These models can be used to predict the behavior of materials at conditions inaccessible to experiment and to gain a fundamental understanding of the microscopic basis for the observed macroscopic properties. A significant fraction of this work involves large-scale numerical calculations on parallel supercomputers and clusters of workstations.

Spanning length and time scales. Significant progress has been made in recent years in computational methodologies that can obtain properties of materials from atomistic-scale simulations. An example is the Gibbs ensemble Monte Carlo method, developed in our group in 1987, which provides a direct way to obtain coexistence properties of fluids. However, many phenomena and properties of interest have time and length scales much greater than can be accessed by atomistic simulations. We are working on computational methodologies that bridge the atomistic (tens of Angstroms) to mesoscale (μm) levels. Promising approaches include coarse-grained (lattice) models, static and dynamic mean-field theories and dissipative particle dynamics.

Self-assembly in surfactant systems. Surfactant solutions exhibit a fascinating range of microstructures and phases, including micellar aggregates and liquid crystalline phases. Understanding aggregation in these simple systems may also elucidate principles underlying biological organization. Surfactants are also used as templates for nanostructured materials. In our work to date, we have developed microscopic models that capture many essential features of real nonionic surfactant behavior. We plan to extend these models to include ionic groups and more complex surfactant architectures. Also of significant interest are surfactant/polymer interactions.


Micelles forming in the system H(30)T(10), where H represents hydrophilic groups (blue) and T hydrophobic (red).

Ionic criticality and phase transitions. We work on understanding phase transitions and the structure of ionic, highly polar and associating fluids. For this purpose, we employ a number of specialized sampling techniques, such as configurational-bias and thermodynamic-scaling Monte Carlo methods. The primary goal of our research in this area is the development of methodologies to allow precise determination of properties for systems with strong interaction forces between constituent particles.