Luminescent Porous Aromatic Frameworks and Metal-Organic Frameworks for photonic and fast scintillation applications

Microporous materials offer synthetic versatility allowing the generation of advanced materials with unique photonic and scintillating properties. Highly luminescent diphenylanthracene (DPA) moieties can be framed into Porous Aromatic Frameworks (PAFs) generating porous nanoparticles with high quantum yield in the solid state[1]. After the diffusion and tethering of sensitizer molecules in the accessible voids inside the materials, each nanoparticle operated as self-standing solid state upconverting materials with potential applications in bio-imaging and photovoltaics. Scintillating materials emit light under excitation with ionizing radiations. They are fundamental for particle physics detectors and for medical imaging. State of the art technologies based on inorganic or polymeric materials produce high light yields or fast time responses, but neither of these standard approaches provide both properties within the same material. An innovative approach based on Metal-Organic Frameworks nanocrystals embedded in polymer matrixes successfully produced composite scintillators with promising light yield and fast rise and scintillation times[2]. High-Z MOFs were generated by coordination of Zirconium-based oxo-hydroxy clusters and highly emissive DPA ligands allowing for the efficient sensitization of the ligand fluorescence. Modulated synthesis produced nanocrystalline MOFs with controlled particle sizes and shapes that can be easily embedded in a continuous polymer matrix to generate self-standing monoliths. The scintillating properties of these composites were characterized showing high light yields and scintillation rise time of ~ 50 ps. These outstanding properties provides fast detection of high-energy radiations and made them suitable for application in detectors for time-of-flight positron emission tomography (TOF-PET). [1] Perego, J.; Pedrini, J.; Bezuidenhout, C. X.; Sozzani, P. E.; Meinardi, F.; Bracco, S.; Comotti, A. and Monguzzi, A. Advanced Materials, 2019, 31 (40), 1903309. [2] Perego, J.; Villa, I.; Pedrini, A.; Padovani, E. C.; Crapanzano, R.; Vedda, A.; Dujardin, C.; Bezuidenhout, C. X.; Bracco, S.; Sozzani, P. E.; Comotti, A.; Gironi, L.; Beretta, M.; Salomoni, M.; Kratochwil, N.; Gundacker, S.; Auffray, E.; Meinardi, F. and Monguzzi, A. Nature Photonics, 2021, https://doi.org/10.1038/s41566-021-00769-z.