2011 You Be The Chemist National Challenge in Philadelphia, PA. Louisiana’s champion, Mr. Thuc

1. Silica-Polypeptide Composite Particles Paul S. Russo, Louisiana State University & Agricultural and Mechanical College, DMR 1005707 This award supports the creation of small (1/1000thof a millimeter) particles, each composed of a solid, glass-like core and magnetic “nougat”, all coated by a soft, protein-like shell that can change its shape in response to stimuli, as do some virus particles. This ability in a synthetic particle can lead to new material phases and devices, such as optical switchers or filters. This year we highlight progress in characterizing the particles. The figure shows an asymmetric flow field flow fractionation / light scattering (AF4/LS) measurement of a standard material that is supposed to be highly uniform in size. Although the particles are quite uniform, separation by AF4 can make them even more so. In turn, that can result in better understanding of the internal structure by methods such as small-angle scattering. Asymmetric flow field flow fractionation chromatogram of standard reference particles reveals that even such high-quality particles exhibit significant size variability and can be separated into more uniform samples. In turn, this may permit better characterization of the interior structure.

2. Silica-Polypeptide Composite Particles Paul S. Russo, Louisiana State University & Agricultural and Mechanical College, DMR 1005707 Technical Broader Impact.Not only can we measure reference materials by the AF4/LS method (previous slide) but our own silica core materials have been improved to almost this level of perfection. We believe this will lead to more uniform total particles (including shells) and tighter reproducibility as we move to studies of thermal transitions. The great uniformity of particles also will contribute to their ability to form colloidal crystals, of interest in modern laser design. Phases composed of highly uniform spheres and untethered polypeptides are expected to have greater uniformity and physical extent, too. Non-technical Broader Impact.Work with the Chemical Educational Foundation’ continues. Four Louisiana educators joined Mr. Thuc Truong and his family in Philadelphia for the national competition and subsequent workshop to improve it. Mr. Truong is slated to join the research group of Prof. David Spivak as an after-school/summer research trainee, making him the 4th Challenge participant to join the Macromolecular research effort at LSU. 2011 You Be The Chemist National Challenge in Philadelphia, PA. Louisiana’s champion, Mr. Thuc Truong, is the tallest student in the middle. The PI worked closely with Mr. Truong’s teacher to prepare him for the competition. Also shown are industry leaders the Students and their parents get to meet.