Gas sorption measurements were performed to determine the pore availability of the material, which is an essential property for many MOF applications. This is especially crucial when a dense matrix, such as an inorganic glass, is employed in MOFcomposites. According to N2 sorption measurements, composites containing higher loads of Ti-MOF produce good results with 327, 618 and 821 m 2 /g BET values for [(Ti-MOF)0.50(IG)0.50], [(Ti-MOF)0.75(IG)0.25] and pristine Ti-MOF, respectively (Table , Figure .a). The BET surface area of the pristine Ti-MOF is substantially smaller than the reported one; this might be due to a partial structural collapse during pelletisation. Carbon dioxide isotherms at 273 and 283 K were also collected, showing a higher CO2 uptake for composites containing a larger proportion of Ti-MOF (Table , Figure .b. and S58). The variation of the ratio MOF/IG vs the gas uptake values is not linear, in fact the amount of gas adsorbed for the [(Ti-MOF)0.50(IG)0.50] and [(Ti-MOF)0.75(IG)0.25] composites is presumably higher than expected (Figure ). This might be due to the presence of small cracks in the pellet surface between domains that allows better carbon dioxide diffusion.