"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."
Static and dynamic light scattering provide real-time, noninvasive characterization of molecular masses and/or particle sizes. They are powerful techniques for characterizing materials such as polymer dispersion, pigments, colloids, etc. This proposal is for the acquisition of a suite of light scattering instruments to be used by researchers in the departments of Chemistry and Physics at Georgetown University. A large amount of the research activities in these two departments involves macromolecular and nanoparticles systems, including studies of macromolecular gels, polymer colloids and molecular aggregation and self-assembly. The main components of this instrument suite will be a multi-angle static light scattering apparatus, a dynamic light scattering attachment, and a differential refractometer, all from Wyatt Technology Corporation (Santa Barbara, CA). With these, we will be able to measure particle sizes in the range of several nanometers to several microns and more importantly, look at the time dependence of the assembly of molecules to form gels, crystals or nanoparticles. The instruments will be used primarily by five faculty members in the Physics and Chemistry departments, as well as their students and other collaborators, on projects ranging from studies of the crystallization of malaria pigment to the formation of gels to crystallization related to kidney and bile stone formation. The acquisition of these instruments will also have a significant effect on the already considerable amount of interdisciplinary activities among the science departments at Georgetown and provide an opportunity for undergraduate and graduate students to develop expertise in this important analytical method.
Layman Summary: When light strikes small particles, part of it is scattered in other directions; this has many effects experienced in daily life, from the ability to see dust particles in a beam of sunlight to the color of the sky. How light is scattered can be used as a powerful measurement technique for learning about the objects from which it scatters. In particular, light scattering methods are useful for measuring sizes and shapes of objects too small to observe with optical microscopes, such as nanoparticles. A number of scientists at Georgetown University are involved in studying how nanoparticles form and are developing new types of nanomaterials. This proposal is for acquiring a set of state of the art light scattering instruments that will enable these materials to be measured in real time and without disturbing their syntheses. One instrument will be for static light scattering: measuring the angular spread of light as it passes through a suspension of particles. The other will be for dynamic light scattering, which uses the rapid fluctuations in the intensity of the scattered light to determine particle sizes. The instruments will be used primarily by five faculty members in the Physics and Chemistry departments, as well as their students and other collaborators, on projects ranging from studies of the crystallization of malaria pigment to the formation of gels to crystallization related to kidney and bile stone formation. The acquisition of these instruments will also have a significant effect on the already considerable amount of interdisciplinary activities among the science departments at Georgetown and provide an opportunity for undergraduate and graduate students to develop expertise in this important analytical method.
