Luijten: Self-assembly driven by electrostatic...
Jan
28
Mon 4:00 PM
When Monday, January 28, 2008
Time
4:00 PM - 5:00 PM
Where LR5
Contact Danielle Jackson
847-491-5586
Group McCormick-Colloquia Engineering Sciences and Applied Mathematics
Joint Applied Math / Materials Science Colloquium
Title: Self-assembly driven by electrostatic interactions: Understanding experiments through new algorithms
Speaker: Eric Luijten, University of Illinois aat Urbana-Champaign
Abstract: Electrostatic interactions play a crucial role in many self-assembly phenomena observed in soft materials and biological systems. The resulting presence of multiple relevant length scales leads to interesting and sometimes counter-intuitive behavior, but often also greatly complicates accurate analytical calculations and computer simulations that could explain the observations. In this seminar, I will present two case studies where recent experimental results have prompted the development of new simulation algorithms. I will demonstrate how these algorithms not only permit new insights in the underlying physical mechanisms, but also have an impact far beyond their original application area. The first case is based upon the geometric cluster algorithm, a rejection-free Monte Carlo method developed by us that accelerates simulations of large classes of size-asymmetric fluids by many orders of magnitude. Very recently, we have been able to incorporate the Ewald summation in this method, which has made it possible to address the self-assembly of synthetic colloids, viruses and proteins while fully accounting for the role of counterions and added salt. The second case focuses on bundles of filamentous actin, an important biopolymer. By means of simulations in the appropriate thermodynamic ensemble, we have uncovered the essential role of salt partitioning in the stability of these bundles. An immediate consequence of these calculations is the possibility to manipulate actin-lysozyme complexes. As has been confirmed in close collaboration with experimentalists, this in turn may open an important new avenue for controlling the activity of antimicrobials in cystic fibrosis patients.
Title: Self-assembly driven by electrostatic interactions: Understanding experiments through new algorithms
Speaker: Eric Luijten, University of Illinois aat Urbana-Champaign
Abstract: Electrostatic interactions play a crucial role in many self-assembly phenomena observed in soft materials and biological systems. The resulting presence of multiple relevant length scales leads to interesting and sometimes counter-intuitive behavior, but often also greatly complicates accurate analytical calculations and computer simulations that could explain the observations. In this seminar, I will present two case studies where recent experimental results have prompted the development of new simulation algorithms. I will demonstrate how these algorithms not only permit new insights in the underlying physical mechanisms, but also have an impact far beyond their original application area. The first case is based upon the geometric cluster algorithm, a rejection-free Monte Carlo method developed by us that accelerates simulations of large classes of size-asymmetric fluids by many orders of magnitude. Very recently, we have been able to incorporate the Ewald summation in this method, which has made it possible to address the self-assembly of synthetic colloids, viruses and proteins while fully accounting for the role of counterions and added salt. The second case focuses on bundles of filamentous actin, an important biopolymer. By means of simulations in the appropriate thermodynamic ensemble, we have uncovered the essential role of salt partitioning in the stability of these bundles. An immediate consequence of these calculations is the possibility to manipulate actin-lysozyme complexes. As has been confirmed in close collaboration with experimentalists, this in turn may open an important new avenue for controlling the activity of antimicrobials in cystic fibrosis patients.
