Highly transparent photochromic films with a tunable and fast solution-like response
Torres-Pierna, Héctor (Institut Català de Nanociència i Nanotecnologia)
Ruiz-Molina, Daniel (Institut Català de Nanociència i Nanotecnologia)
Roscini, Claudio (Institut Català de Nanociència i Nanotecnologia)

Date:	2020
Abstract:	The increasing interest towards photochromic films and their practical applications is driving researchers in the continuous design and synthesis of novel organic photochromic dyes with optimized performances in polymeric matrices. However, whereas their photochromic properties could be readily rationalized in organic liquid solutions, these could not be directly extrapolated to polymers as their performance changes unpredictably upon integration into a solid matrix. This leads to a time-consuming synthetic re-tuning of the dye chemical structure and/or the polymeric medium. To avoid this, herein we report an efficient, straightforward and universal strategy to embed commercial T-type organic photochromic dyes of different nature in a polymeric material without compromising their optimum solution absorption and isomerization kinetics. Our approach is based on trapping emulsified nanodroplets of a hydrophobic solution enclosing the dye into a hydrophilic polymeric matrix. The material is prepared through one single process using commercially available materials, without further modification of the components (the dye and the polymer matrix) nor requiring previous encapsulation steps. The films, which manifest true solution liquid-like and finely tunable photochromic behavior, are also highly transparent, recyclable, and scalable, and show enhanced fatigue resistance, making them highly suitable for different smart glass applications.
Grants:	Ministerio de Economía y Competitividad SEV-2017-0706 Ministerio de Ciencia e Innovación RTI2018-098027-B-C21
Note:	This work was supported by grants from the Spanish Research Agency funds (AEI, grant no. RTI2018-098027-B-C21) and by the European Regional Development Fund (ERDF). The ICN2 is funded by the CERCA programme/Generalitat de Catalunya. The ICN2 is supported by the Severo Ochoa Centres of Excellence programme, funded by the Spanish Research Agency (AEI, grant no. SEV-2017-0706). H. T. P. thanks the Generalitat de Catalunya (AGAUR) for the fellowship Doctorats Industrials. The authors acknowledge Futurechromes S. L. for the funding.
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Hydrophobic solutions ; Isomerization kinetics ; Optimized performance ; Photochromic behavior ; Photochromic dyes ; Photochromic films ; Photochromic properties ; Polymeric matrices
Published in:	Materials Horizons, Vol. 7, issue 10 (Oct. 2020) , p. 2749-2759, ISSN 2051-6355

DOI: 10.1039/d0mh01073a

Postprint 11 p, 1.3 MB

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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