Theoretical Physical Chemistry

Theoretical physical chemistry fundamentally probes the structure and dynamics of matter on length scales ranging from the atomic to the macroscopic world of everyday experience. The intellectual breadth of this field is reflected in the diversity of the research efforts in theoretical physical chemistry at UCLA to be described in more detail below.

The research of this department also has a strong interdisciplinary component. Pursuing our research into the complex organization and properties of matter on these length scales has lead to important and fruitful collaborations with researchers in a number of related scientific and engineering fields including biology, physics, and material science/engineering, the UCLA medical school, as well as the emerging field of nanotechnology.

Professor Gelbart is fascinated by the structural and mechanical properties of viruses. Understanding the complex structure and self-assembly of these nanoscale devices in detail provides a problem that is simultaneously at the forefront of statistical mechanics and the life sciences.

Professor Raphael Levine is currently pursuing research into electronic transport in two-dimensional quantum dot arrays systems that both hold promise for new electronic devices at the nanoscale and allow researchers to probe fundamental questions regarding electron transport in ordered and disordered lattices. In addition to this work and numerous other interests, he investigates chemical reaction dynamics including molecular dynamics extreme conditions such as the hypersonic impact of molecular clusters on solid surfaces.

Professor Alex Levine studies the mechanical properties of a number of biomaterials using polymer physics and statistical mechanics. For example he is exploring stress propagation through polymer networks that are stiff on the length scale of the distance between cross-links. Such polymer gels are not the typical products of synthetic chemistry where the polymer chains are quite flexible. This system, however, is a good starting point to study the mechanical properties of cells that are filled with such a stiff filament network called the cytoskeleton. Professor Levine also explores the hydrodynamics of two-dimensional fluids like lipid bilayers or a surfactant-coated (soapy) air/water interface. Extending hydrodynamics in these areas will inform dynamics of the motions and interactions of transmembrane proteins in cells.

Professor Lin also explores dynamics under extreme conditions in his research on spin turbulence in ultra-high magnetic fields. Understanding this frontier problem in spatiotemporal chaos in a many-body system leads to the development of new NMR imaging techniques that employ the subtle control of chaos to enhance imaging resolution in high-field NMR.

Professor Neuhauser works to develop a more complete theoretical understanding of chemistry on the single molecule scale. This work may also lead toward the development of a new field of molecular electronics in which currents are manipulated in single-molecule devices. Not only are such devices the physical limit of current trends toward the miniaturization of electronic devices, they also open up the possibility of using intramolecular quantum interference effects as a new method of control on the nanoscale. Professor Neuhausers group also investigation networks of such molecular device as well as the more abstract notion of genetic network of genes and their regulatory proteins. Understanding the operation of such complex biomolecular circuits that encode our developmental biology may suggest new therapeutic methods based on the direct manipulation of these genetic networks.

Professor Reiss explores basic issues in statistical mechanics including the physical chemistry of conducting polymers. It is remarkable that hydrocarbon-based materials like these polymers can, in fact, conduct electricity like a metal or like a semiconductor. Due primarily to their interaction with light, they hold the promise of significant technological application in such devices as solar cells and laptop displays. They also provide a testing ground for the study of electronic states in these rare one-dimensional conductors. Professor Reiss studies the nature of collective nuclear/electron motion and associated with the charge carriers in these materials. He also explores the statistical mechanics of a number of other strongly interacting systems including liquids composed of hard spheres and the study of nucleation of liquid droplets from the vapor phase.

Professor Schwartz also explores the dynamics of charge transport in conducting polymers focusing on the intermolecular transport of charge that occurs in conducting polymer thin films. To do so he must explore the dynamics and interactions of charges in the complex environment composed of many polymer chains as perhaps smaller solvent molecules. By understanding the relationship between the charge transport in and structure of these polymeric films, one can develop new fabrication techniques to optimize the electro-optical properties of the materials and bring the technological promise of these polymers closer to fruition. Exploring charge motion in a complex environment also underlies the other, related focus of the research of Professor Schwartz's group the elucidation of chemical reactivity in complex molecular environments. For example, how does the presence of the solvent molecules affect the reactivity of a solute in solution? The complex environment of the reactants must affect the charge distribution and the breaking and forming of bonds between the reactants. In order to investigate chemistry in this ubiquitous but highly complex environment, Professor Schwartz uses sophisticated computational tools to investigate both electronic and nuclear dynamics in such reactions.