Quantitative probe of the dynamics of mass transfer of water in organic porous materials by means of neutron spectroscopy: The case of covalent triazine-based frameworks.

We study the mass transfer and interaction of water through/with two porous covalent triazine-based frameworks (CTFs), by neutron spectroscopy. Inelastic neutron scattering evidences an interaction between CTF-CN and water, not observed for CTF-2, and that is correlated with the large amount of bound water or very slow diffusing water observed for CTF-CN, using quasi-elastic neutron scattering (QENS). The water dynamics is also impacted by CTF-2 but to a lesser extent. The translational diffusion of constrained water in CTF-2 is well quantified by fitting the QENS spectra.