Assessment of matrices influence on thermochemical behavior of novel organic hydrated salt

Energy waste is a key problem in the global effort to increase energy efficiency. A promising solution are thermochemical materials which are commonly founded on a reversible chemical reaction with salts hydrate. During the direct endothermic process the salt dehydrates storing the waste heat, while the reverse exothermic reaction allows to release the previously stored energy. Calcium Lactate pentahydrate (CL) due to its low solubility in water represents a valid candidate for overcoming deliquescence issues.1 However, its applicability is limited by the slow hydration kinetics.2 To this aim, different hybrid CL based materials with five different matrices were prepared. The role of matrices is that of separating CL particles thus promoting the hydration process. For the preparation of CL hybrid materials, two host groups have been selected: mineral (such as silica gel and sepiolite) and carbonaceous matrices (such as exfoliated graphite, graphite oxide and functionalized carbon nanotubes). For all the preparations, different loads (50- 90% wt.) of CL was added to the matrix. An impregnation route was used for the materials preparation. Structural and morphological characterizations of the as prepared materials were carried out. Analyses under dynamic and static vapour conditions were used to evaluate the performances of the synthesized materials. The water uptake results greater in both mineral and carbonaceous materials at 90% wt. of CL load. Further analyses are ongoing to determine the quantitative contribution of the hosts in the hydration process. References [1] E. Mastronardo, E. La Mazza, D. Palamara, E. Piperopoulos, D. Iannazzo, E. Proverbio, C. Milone, Energies, 2022, 15, 4339-51. [2] Y. Sakata, S. Shiraishi, M. Otsuka, Colloids Surf B Biointerfaces, 2005, 46, 135-41.