January 30, 2015 - 3:00pm - 4:00pm
Neutron scattering is a powerful technique that can probe the structure and dynamics of polymer systems. This talk will discuss two examples of using elastic neutron scattering measurements to characterize either the structure of thermodynamics of polymer systems. First, small-angle neutron scattering (SANS) will be used to directly measure the conformations of PMMA that is densely grafted on iron oxide nanoparticles (R = 2.5 nm). These measurements will be compared to predictions using self-consistent field theory (SCFT). In the second example, SANS is used to study the thermodynamics of thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) dissolved in mixtures of deuterated ethanol and water. Interestingly, while both ethanol and water are good solvents for PNIPAM, SANS measurements point to a wide composition region (40-60% water) in which PNIPAM is immiscible at all temperatures.