Levich Institute Seminar Announcement, 10/16/2007
Steinman Hall, Room #312
(Chemical Engineering Conference Room)
Professor Kristen Fichthorn
Penn State University
Department of Chemical Engineering
"Atomic Scale Simulation of Colloidal Nanoparticle Forces"
Nanoparticles hold great promise for a diverse array of materials applications, ranging from nanoelectronic circuits and sensors to bulk materials with novel mechanical properties to biological materials. Two critical challenges with using nanocolloids in these and other technologies are stability and bottom-up assembly of the particles. In contrast to larger particles, where stability and assembly are easier to bring about, in part due to a wealth of sound heuristics based on experiments and theory, for nanocolloids far fewer successful reports exist for stability and especially for assembly.
Historically, the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory has been used to describe electrostatic and van der Waals interactions in colloidal systems.
However, the assumptions of DLVO theory do not apply to nanoparticles. Further, recent studies suggest that forces that are not taken into account by DLVO theory, such as solvation and depletion,
could be important in colloidal nanoparticle systems. From a theoretical point of view, it is possible to simulate colloidal nanoparticles using molecular dynamics. These studies can yield
atomic-scale detail that is not currently accessible with experimental methods and they can be used to resolve the origins and magnitudes of forces between colloidal nanoparticles. I will discuss our
recent work, in which we use molecular dynamics simulations to study the interplay between solvation, van der Waals, and electrostatic forces for model colloidal nanoparticles. These studies indicate
that a wealth of phenomena can occur that can affect colloidal stability, alignment, and assembly.
CURRENT RESEARCH INTERESTS:
Simulation of materials interfaces