Dynamics of Block Copolymer Micelles Revealed by X-Ray Intensity Fluctuation Spectroscopy

We report x-ray intensity fluctuation spectroscopy measurements of the equilibrium dynamics of polymer micelle liquids, composed of polystyrene-polyisoprene block copolymer micelles within a polystyrene homopolymer matrix. The equilibrium dynamics were investigated for times between one and several hundred seconds, and for wave vectors from 0.003 to $0.015{Å}^{-1\mathrm{}}$, far beyond wave vectors that can be studied with visible light. A wave-vector-dependent diffusion coefficient is found.