Novel fluorescent security marker. Part II: application of novel 6-alkoxy-2-amino-3,5-pyridinedicarbonitrile nanoparticles in safety paper
Application of newly investigated fluorescent nanoparticles of 6-alkoxy-2-amino-3,5-pyridinedicarbonitriles as security markers for enhancing the safety property of bagasse-based paper sheets (as valuable documents) was studied. The role of sonication conditions and the type of molecule (morpholinyl or piperidinyl) contained in the heterocyclic compound on production of nanoparticles and their fluorescent behavior were evaluated. The quality of the obtained treated paper was evaluated from examining the fluorescence behavior of the particles-treated paper sheets, in comparison with their fluorescence behavior in water suspension. The success of these investigated fluorescent particles as a security marker was recommended from examining the strength properties of the treated paper and the interaction between the fluorescent particles and the cellulose fibers, via FT-IR-spectra and thermal stability tests, and moreover, from the unfalsifiable safety of the treated documents by erasure technique (chemical and mechanical).