Penetration behavior of an ionic liquid in thin-layer silica coating: Ionic liquid deuteration and neutron reflectivity analysis

Abstract A quantitative analysis method for monitoring liquid penetration into nanosize thin layer samples was developed using neutron reflectivity (NR). In this study, we synthesized a partly deuterated ionic liquid (IL) and studied its penetration behavior in perhydropolysilazane-derived silica (PDS) thin layers using NR. The penetration depth of the deuterated IL was estimated to be 184 A for the 24 h IL-submerged sample and 410 A for the 72 h IL-submerged sample. In addition, using the obtained penetration depth, an apparent penetration rate constant ( k app ) of 0.024 h −1 was evaluated. Thus liquid penetration behavior in PDS thin layer samples can be quantitatively discussed by evaluation of k app using NR analysis.