Photoactive perfluorinated ionomeric transparent coatings in the oxidative abatement of hydrosoluble pollutants in turbid suspensions Walter Navarrini*(1,2), Federico Persico(1,2), Maurizio Sansotera(1,2) (1) Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, 20131, Milano, Italy. (2) Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Via G. Giusti 9, 50121 Firenze, Italy. *Walter Navarrini: Tel: +39.02.2399.3035; email address: walter.navarrini@polimi.it; The abatement of organic pollutants in water phase promoted by photoactive titanium dioxide has been widely studied in the last decade [1]. Despite the high photodegradative rates guaranteed by slurry TiO2, its industrial use is strongly limited by the catalyst recovery cost. To overcome this obstacle powder TiO2 was immobilized into a multilayer ionomeric-perfluorinated matrix and the activity of this Photoactive Coating (PAC) was studied. In order to obtain the correct interaction between the activated TiO2 and the polluted aqueous solutions the polymeric matrix must be characterized by high chemical resistance, high transparency towards UV light, good wettability and good permeability to oxygen and water vapor [2,3]. The multilayer coating photocatalytic activity towards hydrosoluble organic pollutants was evaluated in clear as well as in highly turbid conditions obtained by dispersing barium sulphate microparticles in the polluted solution. The perfluorinated multilayer photoactive coating was applied directly on the UV source and employed as substrate for immobilization of the photocatalyst. A TFE/perfluorodioxole copolymer double-layer acted as primer; a dispersion of TiO2 in the perfluorinated ionomeric solution of a copolymer between TFE/perfluorosulphonylvinylether acted as photoactive layer. The strong acidity of the ionomeric side chains conferred hydrophilicity to the coating , allowing a good interaction with the polluted aqueous solutions. Rhodamine B-base (RhB) and Crystal Violet (CV) were used as organic hydrosoluble pollutants and their concentration in solution was monitored by UV-Vis spectroscopy and HPLC-MS technique. In both clear and turbid conditions, TiO2-embedded transparent fluorinated coating revealed higher photocatalytic activity than merely dispersed TiO2 (Image1). This behavior was particularly evident at low pollutant concentrations. In addition, catalyst immobilization prevented TiO2 separation and catalyst losses, allowing the development of a simple and efficient continuous apparatus. I Image 1. Degradative efficiency of PAC compared to the performances obtained with slurry TiO2 References [1] M. Sansotera, et al., Appl. Catal., B, 148 (2014) 29. [2], F. Persico, et al., Thin Solid Films, 545 (2013) 210. [3] W. Navarrini, et al., Prog. Org. Coat., 74 (2012) 794.

Photoactive Perfluorinated Ionomeric Transparent Coatings in the Oxidative Abatement of Hydrosoluble Pollutants in Turbid Suspensions

NAVARRINI, WALTER MAURIZIO;PERSICO, FEDERICO;SANSOTERA, MAURIZIO
2014-01-01

Abstract

Photoactive perfluorinated ionomeric transparent coatings in the oxidative abatement of hydrosoluble pollutants in turbid suspensions Walter Navarrini*(1,2), Federico Persico(1,2), Maurizio Sansotera(1,2) (1) Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, 20131, Milano, Italy. (2) Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Via G. Giusti 9, 50121 Firenze, Italy. *Walter Navarrini: Tel: +39.02.2399.3035; email address: walter.navarrini@polimi.it; The abatement of organic pollutants in water phase promoted by photoactive titanium dioxide has been widely studied in the last decade [1]. Despite the high photodegradative rates guaranteed by slurry TiO2, its industrial use is strongly limited by the catalyst recovery cost. To overcome this obstacle powder TiO2 was immobilized into a multilayer ionomeric-perfluorinated matrix and the activity of this Photoactive Coating (PAC) was studied. In order to obtain the correct interaction between the activated TiO2 and the polluted aqueous solutions the polymeric matrix must be characterized by high chemical resistance, high transparency towards UV light, good wettability and good permeability to oxygen and water vapor [2,3]. The multilayer coating photocatalytic activity towards hydrosoluble organic pollutants was evaluated in clear as well as in highly turbid conditions obtained by dispersing barium sulphate microparticles in the polluted solution. The perfluorinated multilayer photoactive coating was applied directly on the UV source and employed as substrate for immobilization of the photocatalyst. A TFE/perfluorodioxole copolymer double-layer acted as primer; a dispersion of TiO2 in the perfluorinated ionomeric solution of a copolymer between TFE/perfluorosulphonylvinylether acted as photoactive layer. The strong acidity of the ionomeric side chains conferred hydrophilicity to the coating , allowing a good interaction with the polluted aqueous solutions. Rhodamine B-base (RhB) and Crystal Violet (CV) were used as organic hydrosoluble pollutants and their concentration in solution was monitored by UV-Vis spectroscopy and HPLC-MS technique. In both clear and turbid conditions, TiO2-embedded transparent fluorinated coating revealed higher photocatalytic activity than merely dispersed TiO2 (Image1). This behavior was particularly evident at low pollutant concentrations. In addition, catalyst immobilization prevented TiO2 separation and catalyst losses, allowing the development of a simple and efficient continuous apparatus. I Image 1. Degradative efficiency of PAC compared to the performances obtained with slurry TiO2 References [1] M. Sansotera, et al., Appl. Catal., B, 148 (2014) 29. [2], F. Persico, et al., Thin Solid Films, 545 (2013) 210. [3] W. Navarrini, et al., Prog. Org. Coat., 74 (2012) 794.
2014
Fluoro Polymer 2014
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/901157
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