The present work investigates the physicochemical stability of spray paints when irradiated with artificial solar light (at spectral range 300–800 nm). This research highlights the importance of understanding the materials used in street art and public murals, recognising them as a significant component of contemporary cultural heritage. By examining the stability and degradation of spray paints toward solar light exposure, the study aims to contribute to the preservation of contemporary murals, which reflect current social and cultural narratives. A physicochemical approach was employed for the study of spray paints’ physical and thermal properties, as well as the effect of specific photochemical ageing reactions/processes. The photochemical ageing results were compared with reference (unaged) samples. Specifically, a multi-technique approach was applied using stereo microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measurement, colorimetry, glossimetry, differential scanning calorimetry (DSC), UV-Vis spectroscopy, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and pyrolysis-GC/MS (Py-GC/MS). The photodegradation of the spray paints occurred from the first 144 h of solar light irradiation, resulting in changes in morphology, colour, gloss, roughness, and wettability. Regarding photochemical stability, ageing seems to affect the binders more than the synthetic organic pigments and the inorganic fillers. In particular, acrylic binders showed small chemical changes, whereas the alkyd, nitrocellulose, and styrene binders underwent severe chemical modification. The results suggest that simulated daylight irradiation prompts the migration of additives toward the surface of the spray paint films. In addition, the results of the analyses on the white spray paints in comparison with the coloured paints (from the same manufacturer) showed that there seems to be an active distinct photoageing mechanism involving titanium dioxide, but the whole issue needs further investigation.

Mixed matrix membranes (MMMs) containing UiO‐type metal‐organic frameworks (MOFs) have shown excellent potential for CO₂ separation processes due to their unique permeability and selectivity properties. However, while the performance of MOF‐based MMMs has been widely studied, the effect of structural defects and polymer‐filler compatibility are not yet fully understood. In this work, the CO₂ separation performance of Pebax MH1657‐based MMMs is systematically evaluated incorporating 5–20 wt% of Zr‐based MOF, including UiO‐66, UiO‐67, and two defect‐engineered UiO‐66 analogues, featuring extended linker (UiO‐66_A) or cluster (UiO‐66_F) vacancies. The structural, morphological, and thermal properties of the membranes are thoroughly characterized, with emphasis on correlating these features with gas transport performance. Single‐gas permeation experiments (CO₂, CH₄, H₂) reveal that incorporating UiO nanoparticles within the matrix consistently enhanced CO₂ permeability, reaching 145 Barrer for the 20 wt% UiO‐66_F MMM, a 216.4% increase over the neat membrane. CO₂/CH₄ and CO₂/H₂ selectivities also improve upon increasing MOF loadings, with UiO‐66_F achieving values of 25 and 18, respectively. This study provides insights for designing high‐performance MMMs for CO₂ separation applications, such as biogas upgrading and hydrogen purification.