MANUAL METHOD FOR THE DEPOSITION OF PHOTOLUMINESCENT INKS BASED ON MIXED LOFs APPLIED TO DOCUMENT ENCONDING

In this work, the process of synthesis of Metal-Organic Frameworks containing lanthanide ions (LOFs), accelerated via a precipitating agent, capable of accelerating the process of nucleation of MOF crystals, in order to explore the optical properties of this precursor solution (SP_Gd/EU-MOF), as a quick-response photoluminescent material in the coding of official documents. The SP_Gd/Eu-MOF was deposited on the paper substrates manually, using pilot board master liquid ink pens with medium tip. The SP_Gd/Eu-MOF, was characterized by photoluminescence spectroscopy after crystallization on a vial and at surface of the papers, and the spectra showed identical spectral profiles, showing that the interaction with the substrate surface did not promote significant changes in the site symmetry of Eu3+ ions. After being deposited, the material was excited by UV radiation (λ = 254 nm), and emitted the red color characteristic of the Eu3+ ion. The SP_Gd/Eu-MOF, showed good mechanical stability in the abrasiveness test carried out with a rubber remaining deposited on the substrate, demonstrating it is potential to act as proof of authenticity in the encoding of documents, revealing itself as another low cost alternative for the deposition of photoluminescent inks.