DSC experiments on the three composites and the pure glass were carried out after TGA experiments (Fig. ). Firstly, one cycle until 420 °C was measured for each sample, to observe the recrystallisation process (Fig. ). The recrystallisation temperature of the ball milled sample of the pure glass was shifted to lower temperatures, due to the higher amount of water and potential defects at the surface of the glass after ball-milling. Surprisingly, both the Tgs and Trs of the physical mixtures and composites did not change appreciably, in contrast to the pure sample. We ascribe this to the ZIF-8 being able to capture water from the surface of the inorganic glass, thus preventing changes in glass structure and thermal behaviour. Alternatively, the ZIF may acts as a third component of the glass mixture, stabilising the glass network, similar to ternary ZnO-Na2O-P2O5 glasses. The PXRD pattern after the recrystallisation process confirmed formation of a mixture of Na3P3O9, and the existing ZIF-8 (Fig. ).