Abstract:

The necessity of understanding many biological materials in molecular scales and the rational development of advanced nano-scale materials require a fundamental knowledge of the relationship between structure and physical properties at multiple length scales.  Scattering methods are uniquely suited to obtain the necessary information through carefully designed experiments. Among them, small angle neutron scattering has proven to be a powerful probe to study structural properties with length scale from about 1 nm to 500 nm noninvasively. In this talk, I will demonstrate how small angle neutron scattering can be used to provide key information on the physics of different materials. My attention will primarily focus on determining the effective interaction potential between nano-sized particles in solutions, such as proteins and drug delivery vehicles. I will show that by combining statistical mechanics theories and small angle neutron scattering, we can unambiguously understand how nano-particles interact in solution, through which the rich information of the individual particle, such as morphology of particles, particle clustering effect, effective charge and softness of a particle, can be uniquely obtained. In addition, I will also present our understanding of nano-precipitates in a superalloy studied with small angle neutron scattering.