The project “Hybrid Fast-Responsive Nanoparticles as Printable Anitcounterfeiting Markers (NANOINKS)” has been awarded with a LLAVOR grant for innovative projects with potential for being incorporated into the production sector, granted by the AGAUR (Agència de Gestió d’Ajuts Universitaris i de Recerca, Generalitat de Catalunya), FEDER (Fons Europeu de Desenvolupament Regional) and Secretaria d’Universitats i Recerca del Departament d’Empresa i Coneixement de la Generalitat de Catalunya.
In the Nanosfun research group, various photoactive switchable materials based on phase-change-materials (PCMs) and colour/fluorescent dyes have been recently designed and developed. These dyes/PCM mixtures modify their colour/fluorescence depending on the state (solid or liquid) of the PCM, which is determined by the temperature of the system. Recently, by adding a third component in the mixture, we demonstrated that the solid-to-liquid transition can also be triggered by light irradiation in the near infrarred region (NIR).
These mixtures have been used to prepare switchable fluorescent/coloured materials with advanced responsive properties: multifunctionality (fluorescent/colour changes) and multiresponsiveness (reversible/irreversible switch activated by both temperature and NIR irradiation). These features, contained in one single material, provide a suitable complexity for the preparation of a new generation of anticounterfeiting markers. However, though the potential application of this multi-responsive photoactive material has been validated (TRL = 2) by depositing the different components onto a piece of papers and applying heat and/or NIR irradiation, the technology still requires a further development for its integration in real products (labels, banknotes, documents).
For this, it is needed that the material is printable onto paper-type substrates through standard printing techniques (e.g. screen/inkjet printing, spray-coating, etc.). It is thus necessary formulating the switchable photoactive material as printable inks. Along with this project, the different key components of the material will be nanostructured through nanoemulsion methods (expertise of Nanosfun) and integrated into the ink suspension. The nanomaterials-based ink will be prepared and adapted (tuning solvent, thickeners, binders and stabilizers) according to the printing technique. Different inks with distinct combinations of the photoactive multi-responsive materials will be fabricated to demonstrate the versatility of the technology.
The ink development will be partially carried out subcontracting external research centres with experience in this field. On the other hand, companies related to the anticounterfeiting market will be contacted to address the printable marker development towards the key technical requirements of the anticounterfeiting industry (e.g. paper type, printing scale and resolution of draws).
The obtained inks will be printed through different techniques onto paper substrates of distinct grammage. The final printed papers will be validated by characterizing the optical behaviour upon temperature and NIR irradiation.
Dr. Àlex Julià (Entrepreneur Scientist)
Jaume Ramón Otaegui Rabanal (PhD Student)
Dr. Claudio Roscini (Principal Investigator)
Dr. Daniel Ruiz-Molina (Group Leader)
This project has been co-financed by the European Union through the European Regional Development Fund (ERDF).
(Grant Number: 2019 LLAV 00073)