Start
Apr 23, 2009 - 16:00
End
Apr 23, 2009 - 17:00
Venue
Room 240 (Computer Lab)
Event Type
Speaker
Abhijit Chatterjee Los Alamos New Mexico USA
Title
Bottom-up Multiscale Modeling based Rational design for chemical engineering applications.
Abstract First-principles models at electronic and atomic scales offer exciting opportunities for rationally designing novel chemical engineering technologies with a broad range of applications. They can accurately capture the underlying transport chemistry and thermodynamics of many complex physical systems. However the use of first-principles methods for design is limited by two challenges which renders these methods computationally intractable - a theme that is found to recur in several systems. The first challenge is overcoming the large separation of length and time scales to reach experimentally meaningful scales typically ranging from nanometers to centimeters and picoseconds to minutes. The second challenge is the combinatorial complexity associated with generating structure-property-fabrication phase diagrams for use in rational design of materials. In this talk I will be presenting a bottom-up multiscale modeling framework which we have developed recently to overcome these underlying challenges by deriving a hierarchy of atomistic mesoscopic and continuum models directly from first-principle methods while retaining the accuracy.Bottom-up multiscale models are extremely useful for chemical engineering design as they can i) provide fundamental insights into key mechanisms at different scales that cannot be modelled with classical continuum equations ii) help discover new materials for improving the performance and/or reducing cost and iii) enable the prediction of device performance under different operating conditions and/or at long time scales. The strength of these methods will be highlighted through a specific example of design of self-assembled high-density nanoparticle arrays for catalytic or electronic applications. Current approaches for fabricating high-density nanoparticle arrays rely on trial-and-error. I will present a systematic rational design strategy that employs bottom-up multiscale models in conjunction with optimal control theory to identify the fabrication conditions that lead to the desired nanoparticle array. Atomistic coarse-grained and continuum bottom-up multiscale models will be employed to model the self-assembly of the nanoparticles and to generate a structure-fabrication phase diagram for the nanoparticles array. Use of these methods for rationally designing energy conversion and storage technologies will also be discussed.