The aim of this proposal is to study the effect of adding different Ionic Liquids (ILs) to a POPC phospholipid membrane. Recent experiments (fluorescence spectroscopy and AFM) and MD simulations have shown that ILs can be incorporated into POPC bilayers, modifying their properties and undermining their stability. Those results have important implications concerning the toxicity of ILs and merit further experimental verification. We propose to investigate the structural and the dynamical properties of the system POPC+water(+IL) for three prototypical ILs ([bmim][Cl], [bmim][PF6], [bmim][Tf2N]). Neutron diffraction and reflectivity will allow determining the changes occurring in the membrane structure when different ILs are added, while the dynamical properties will be determined by QENS using a combination of a TOF and a backscattering spectrometers; using lipids with deuterated chains and deuterated water we will focus on the determination of the head group motion. The results will serve to validate the force fields employed in the simulations, as well as to identify the role of the solvent (water) in the evolution of the bilayer structure and stability upon the addition of ILs.