Assessment of VOCs Material/Air Exchanges of Building Products Using the DOSEC®-SPME Method

ACTInternational audienceUsing low emissive materials in building is an effective way to reduce indoor concentrations of pollutants such as VOCs. Material emissions are assessed by the ISO 16000-9 standard. This procedure is time-consuming and is not suitable for on-site measurements. This work aimed in assessing an alternative method, DOSEC\textregistered-SPME, for simple measurements. To validate it, emissions of 30 materials were characterized by both ISO 16000-9 and DOSEC\textregistered-SPME. A first correlation was found between the two methods for formaldehyde emissions of raw materials. This encouraging result allows considering the development of new decision making tools for the selection of healthy building materials

Nanoporous sponges and proven chemical reactions for the trapping and sensing of halogenetated gaseous compounds

International audienceThe literature is well illustrated with examples of porous materials elaborated via the sol-gel process, which display high adsorption surface area suitable for the trapping of volatile organic compounds (VOC). Very often, the porous network of these materials is randomly distributed in terms of pore size. However, some materials can display very ordered nanostructures with uniform pore sizes or hierarchical structures with microscopic (< 2 nm) and mesoscopic (2-60 nm) domains. The utility of such organized media and the possibility of reproducing liquid phase chemical reactions in these confined environments are here discussed with regards to their potentiality as sensitive layers of chemical sensors for the detection of gaseous pollutants. To illustrate the potentiality of the porous materials and the importance of the chemical reactivity at gas-solid interfaces, an example of a chemical sensor which detects chlorine, a toxic industrial gas encountered in microelectronics and semiconductor industries, will be given

N-doped TiO 2 by low temperature synthesis: Stability, photo-reactivity and singlet oxygen formation in the visible range

International audienceN-doped TiO 2 (NDTs) were prepared by sol-gel synthesis at low temperature starting from nanocolloidal TiO 2 and triethylamine according to well-known procedures. Diffuse reflectance UV (DRUV) spectroscopy showed a shift of the absorption to the visible range, while diffuse reflectance IRFT (DRIFT) evidenced the presence of a chemisorbed complex involving triethylamine. Powder XRD showed the sole formation of anatase polymorph of TiO 2 while XPS indicated successful incorporation of nitrogen. Our data are globally consistent with previous literature results, but emphasize the low thermal and photochemical stability of the nitrogen complex under air. Di-n-butylsulfide photo-oxidation in acetonitrile solution was successfully carried out under irradiation at 420 and 350 nm. The reaction rates were slower under visible light and the product distribution was very dependent upon the wavelength. Our results are discussed in parallel with the literature data assuming the favoured formation of singlet oxygen under visible light. © 2010 Elsevier B.V. All rights reserved

Assessment of volatile organic compounds and aldehydes exchanges at the air/material interface of building products and their assemblies: towards improving selection criteria of building materials

International audienc

Assessment of volatile organic compounds and aldehydes exchanges at the air/material interface of building products and their assemblies: towards improving selection criteria of building materials

International audienc

Singlet oxygen in microporous silica xerogel: Quantum yield and oxidation at the gas-solid interface

International audienceThe quantum yields of singlet oxygen (1O2) production (ΦΔ) and 1O2 lifetimes (τΔ) at the gas-solid interface in silica gel material are determined. Different photosensitizers (PS) are encapsulated in parallelepipedic xerogel monoliths (PS-SG). PS were chosen according to their known photooxidation properties: 9,10-dicyanoanthracene (DCA), 9,10-anthraquinone (ANT), and a benzophenone derivative, 4-benzoyl benzoic acid (4BB). These experiments are mainly based on time-resolved 1O2 phosphorescence detection, and the obtained ΦΔ and τΔ values are compared with those of a reference sensitizer for 1O2 production, 1H-phenalen-1-one (PN), included in the same xerogel. The trend between their ability to oxidize organic pollutants in the gas phase and their efficiency for 1O2 production is investigated through photooxidation experiments of a test pollutant dimethylsulfide (DMS). The ΦΔ value is high for DCA-SG relative to the PN reference, whereas it is slightly lower for 4BB-SG and for ANT-SG. ΦΔ is related to the production of sulfoxide and sulfone as the main oxidation products for DMS photosensitized oxidation. Additional mechanisms, leading to C-S bond cleaveage, appear to mainly occur for the less efficient singlet oxygen sensitizers 4BB-SG and ANT-SG. © 2007 Wiley-VCH Verlag GmbH &amp; Co. KGaA

Photocatalytic air-purifyers for VOC degradation in indoor air : european standard and pilot room experiments

International audienc

DOSEC-SPME : a new technique to assess the VOC emission of material

International audienc