Directing Colloidal Systems with DNA and Magnetic Fields

Lisa Biswal
Rice University
Thursday, March 5, 2015
North Carolina State University Campus | 4:30pm

One of the most exciting areas in colloid research is the control of interparticle interactions to generate new structures.   The ease of tuning interactions, size, shape and composition has made these nano- and micrometer sized particles appealing probes for a number of fundamental studies. I will describe how my group has developed synthetic materials consisting of chains of patterned magnetic colloids that have rigidity and length specificity. These chains have demonstrated capability for folding, self-assembly, and specific chemical recognition. A key obstacle to assembling these and other materials is understanding the fundamental chemistry and physics of the assembly processes. Our chains are comprised of paramagnetic particles that have been linked together with DNA. This is classic bead-spring-bead model that is often used to describe polymer chains. I will describe the formation mechanism and stability of these DNA-linked magnetic particle chains. I will also describe a model that describes the total energy landscape that describes the inter-particle interactions and provides a workable theory toward the optimization of experimental parameters in synthesizing more stable and reliable colloidal assemblies.