Title: | Vapochromic Behaviour of Polycarbonate Films Doped with a Luminescent Molecular Rotor |
Author(s): | Minei P; Ahmad M; Barone V; Brancato G; Passaglia E; Bottari G; Pucci A; |
Address: | "Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy. Istituto di Chimica dei Composti Organo Metallici (ICCOM), Consiglio Nazionale delle Ricerche, UOS Pisa, Via G. Moruzzi 1, 56124 Pisa. Departamento de Quimica Organica, Universidad Autonoma de Madrid, 28049, Cantoblanco, Spain. IMDEA-Nanociencia, Campus de Cantoblanco, C/Faraday 9, 28049 Madrid, Spain. Dipartimento di Chimica e Chimica Industriale, Universita di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy. INSTM, UdR Pisa, Via G. Moruzzi 13, 56124 Pisa Italy" |
ISSN/ISBN: | 1042-7147 (Print) 1099-1581 (Electronic) 1042-7147 (Linking) |
Abstract: | "We report on vapochromic films suitable for detecting volatile organic compounds (VOCs), based on polycarbonate (PC) doped with 4-(triphenylamino)phthalonitrile (TPAP), a fluorescent molecular rotor sensitive to solvent polarity and viscosity. PC films of variable thickness (from 20 up to 80 microm) and containing small amounts of TPAP (0.05 wt.%) were prepared and exposed to a saturated atmosphere of different VOCs. TPAP/PC films showed a gradual decrease and red-shift of the emission during the exposure to solvents with high polarity index and favourable interaction with the polymer matrix such as THF, CHCl(3), and acetonitrile. In the case of the most interacting solvents (THF and CHCl(3)), TPAP/PC films also showed a fluorescence increase at longer exposure times, as a consequence of an irreversible, solvent-induced crystallization process of the polymeric matrix. The vapochromism of TPAP/PC films is rationalized on the basis of alterations of the rotor intramolecular motion upon solvent uptake by PC and polarity effects of the microenvironment. Interestingly, the fluorescence response of the TPAP/PC films shows a non-trivial, tuneable dependence on film thickness during the second solvent-exposure stage. The latter effect is attributed to a variable extent of the crystallization process occurring in the PC films. This observation promptly suggests, in turn, an effective procedure to modulate the spectroscopic response in such functionalized polymeric materials through the precise control of the film thickness" |
Keywords: | fluorescent molecular rotors polycarbonate films vapochromism volatile organic compounds; |
Notes: | "PubMed-not-MEDLINEMinei, Pierpaolo Ahmad, Muzaffer Barone, Vincenzo Brancato, Giuseppe Passaglia, Elisa Bottari, Giovanni Pucci, Andrea eng 320951/ERC_/European Research Council/International England 2016/04/01 Polym Adv Technol. 2016 Apr; 27(4):429-435. doi: 10.1002/pat.3688" |