Dynamics of alkane mixtures in silicalite pores

The transport of n-butane – methane mixtures in silicalite has been studied at 200 K using molecular dynamics simulations and quasi-elastic neutron scattering experiments. The dependence on the wave vector of the half-width at half-maximum of the incoherent dynamic structure factor is indicative of a jump diffusion process. Distributions of the jump lengths of methane using a coarse-grained jump model have shown that the jump lengths are widely distributed between 0 and 15 Å, the mean jump length being a decreasing function of the loading. Self-diffusivity values calculated from the dynamics simulations are in excellent agreement with the experimental measurements from quasi-elastic neutron scattering