In this talk I will discuss membrane and protein dynamics with respect to their detection by neutron spin echo (NSE).
Membranes: I will first review the so-called "Zilman-Granek theory" for membrane dynamic structure factor for the case of an embedding purely viscous solvent [1,2]. Next, I will discuss more recent generalizations and refinements: (i) A membrane surrounded by two semi-infinite continuous viscoelastic fluids . (ii) A membrane surrounded by two semi-infinite structured viscoelastic fluids, such as semi-dilute polymer solutions . (iii). Fluid-like, short-time, thickness fluctuations  that are based on the Brochard-Lennon "red blood cell" mode. Open questions and controversies will be discussed.
Proteins: A fractal-like approach to proteins, and the associated universal protein dynamics, will be presented [6-8]. I will further discuss the implications on the dynamic structure factor and NSE measurements on proteins in solution [9,10], with emphasis on the current limitations.
Dr. Christian Franz
Dr. Christian Lang