Incoherent quasi-elastic neutron scattering from fructose-water solutions

Quasi-elastic incoherent neutron scattering (QENS) was used to study the dynamics of 4, 29, and 60 wt % solutions of fructose in deionized water at 300 K. Both the jump-diffusion and stretched exponential models were used to analyze the data, enabling the determination of the structural relaxation rate 1/τ and the stretch exponent β as functions of fructose concentration. The analysis of the neutron scattering data based on the jump-diffusion model is consistent with a transition from continuous to "hopping" or jump diffusion at 29 wt % fructose concentration observed in recent simulations of this same system. The analysis based on the stretched exponential model suggests that this change occurs at a higher fructose concentration.