ChBE Seminar Series: Boualem Hammouda
Tuesday, February 12, 2013
11:00 a.m.-11:00 a.m.
Room 2108 Chemical and Nuclear Engineering Bldg.
Professor Jeffery B. Klauda
Probing Nanoscale Structures Using Small-Angle Neutron Scattering
National Institute of Standards and Technology
Center for Neutron Research
Small-angle neutron scattering (SANS) is a popular characterization method for the investigation of nanoscale structures. It has been effective in research areas like polymers, complex fluids and in biology. Recent results will be described. (1) The structure and miscibility thermodynamics of the simplest water-soluble polymer (polyethylene oxide or PEO) in solution will be described. PEO/water solution phase separates upon heating while PEO/ethanol solution phase separates upon cooling. PEO solution in water/ethanol mixtures shows an interesting transition region with no hint of phase separation at all. (2) A water-soluble Pluronic copolymer self assembles into a series of micellar morphologies upon heating. These include spherical, cylindrical, and lamellar morphologies as well as a vesicle formation phase. The effect of hydrostatic pressure on the phase boundaries has also been investigated. (3) The structure of a kinase protein complex and its inhibitor will be described as well.