Tailored SAPO-34/Graphite Adsorbent Composite Coatings on Aluminum Substrate for Energy Sustainable Sorption Technologies

This paper explores a novel composite adsorbent coating applied to an aluminum support. This coating incorporates SAPO-34 and exfoliated graphite fillers within a sulfonate polyether ether ketone (S-PEEK) matrix, offering a promising avenue for energy-efficient adsorption technologies. Composite coatings, containing SAPO-34 zeolite as the primary adsorbent (80–95 wt.%) and exfoliated graphite as a conductive additive (5 wt.%) were produced. A drop-casting technique was employed to deposit the composite mixtures onto aluminum substrates. The coatings exhibited excellent adhesion to the metal substrate, as proved by a pull-off strength higher than 1.0 MPa. The morphological characterization revealed a uniform dispersion of both additives within the host material. To evaluate their adsorption/desorption behavior, equilibrium water vapor adsorption isobars were determined at a constant pressure of 11 mbar across a 30–120 °C temperature range. The adsorption/desorption tests showed the composite coatings reached 26–30% water uptake, indicating that the matrix did not obstruct the water vapor mass transfer, and the zeolite exhibited active participation in the adsorption/desorption process. These results suggest that this material may be a promising candidate for energy saving systems.