Structural investigation of water-acetonitrile mixtures: Small-angle and wide-angle neutron diffraction study compared to molecular dynamics simulation

In present work we report small-angle and wide-angle neutron diffraction study compared to molecular dynamics simulation on water-acetonitrile system. From small-angle scattering measurements resulted that the correlation length, as well as the density and concentration fluctuation have maximum around xan = 0.38; these findings are in agreement with previous results found, namely, that a strong microheterogeneity exists in acetonitrile-water system in the range of xan = 0.2-0.6 acetonitrile mole fraction. The total g(r) functions of mixtures obtained from wide-angle scattering are compared with molecular dynamics simulation results and they show an overall good agreement.