Ketocyanine-Based Materials for Near Infrared-to-Visible Thermochromism
López, Alex Julià (Institut Català de Nanociència i Nanotecnologia)
Muñoz Pérez, Noel (Institut Català de Nanociència i Nanotecnologia)
Magerramov, Ruslan (Institut Català de Nanociència i Nanotecnologia)
Puyol Bosch, M. del Mar (Universitat Autònoma de Barcelona. Departament de Química)
Crugeira, Ferran (Institut Català de Nanociència i Nanotecnologia)
Miltsov, Sergey (Russian Academy of Sciences)
Ruiz-Molina, Daniel (Institut Català de Nanociència i Nanotecnologia)
Roscini, Claudio (Institut Català de Nanociència i Nanotecnologia)

Date:	2025
Abstract:	Thermochromic materials with tunable optical absorption over the NIR and visible spectral regions, and exhibiting colorless-to-colored transitions, are of interest in relevant applications such as invisible security inks or solar light-energy management. Despite so, the most common commercial thermochromic materials, based on phase-change-material mixtures of spirocompounds (leuco-dyes), allow narrow spectral modulation within the UV/vis regions and mostly produce colored-to-colorless transition, hampering their applicability beyond novelty products. In contrast, materials intrinsically thermochromic in the NIR, require time-consuming syntheses for their spectral and transition temperature tunability. Herein these challenges are overcome by replacing conventional leuco-dyes with Ketocyanines that exhibit strong color sensitivity on external multifactor, i. e. polarity, aggregation state, and pH, through different intermolecular interaction mechanisms, allowing fine and straightforward spectral tunability. Their absorption can be further shifted to the NIR region (λmax = 870 nm) by increasing the number of methine units, giving access to the desired colorless-to-colored transition (Δλ = 280 nm), via negative thermochromism. The preserved transitions of the microstructured mixtures are of interest for future thermochromic inks. Finally, their acid/base vapors response makes these multistimuli responsive materials highly attractive for applications such as anti-counterfeiting, bioimaging, and optical information storage for food packaging.
Grants:	Agencia Estatal de Investigación PID2021-127983OB-C21 Agencia Estatal de Investigación PID2020-117216RB-I00 Agencia Estatal de Investigación TED2021-131709B-I00 Agencia Estatal de Investigación CEX2021-001214-S Agència de Gestió d'Ajuts Universitaris i de Recerca 2020-DI-2
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Anti-counterfeiting ; Energy storage ; Near-infrared optical modulation ; Negative thermochromism ; Phase-change-materials
Published in:	Advanced optical materials, Vol. 13, issue 9 (March 2025) , art. 2401411, ISSN 2195-1071

DOI: 10.1002/adom.202401411

16 p, 3.7 MB

The record appears in these collections:
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles