Tuesday, 26 June 2007 - 2:40 PM
Clayton 120
293

Imaging Energy Landscapes with Concentrated Diffusing Colloidal Probes

Pradipkumar Bahukudumbi, Gregory E. Fernandes, and Michael A. Bevan. Texas A&M University, College Station, TX

The ability to locally interrogate interactions between colloidal particles and energetically patterned surfaces provides essential information to design, control, and optimize template directed self-assembly processes. Although numerous techniques are capable of characterizing local physicochemical surface properties, no current method resolves interactions between colloids and patterned surfaces on the order of the thermal energy kT, which is the inherent energy scale of equilibrium self-assembly processes. In this talk, we describe video microscopy measurements and an inverse Monte Carlo analysis of diffusing colloidal probes as a means to image three dimensional free energy and potential energy landscapes due to physically patterned surfaces. In addition, we also develop a consistent analysis of self-diffusion in inhomogeneous fluids of concentrated diffusing colloidal probes on energy landscapes, which is important to the temporal imaging process and to self-assembly kinetics. Results of Monte Carlo and Brownian Dynamics simulations will also be reported to verify the analysis and interpretation of experimental findings. Extension of the concepts developed in this work suggest a general strategy to image multi-dimensional and multi-scale physical, chemical, and biological surfaces using a variety of diffusing probes (i.e. molecules, macromolecules, nanoparticles, colloids).