New compact technology for cabin air purification based on photocatalytic optical fiber textile

SSCI-VIDE+CARE+LLM:CGUInternational audienceNon

Innovative photocatalytic optical fiber textile: for water and air treatment

SSCI-VIDE+CARE:ECI2D+LLM:EPU:CGUInternational audienceNon

TiO2 Coated Luminous Textile : Ideal Photocatalytic System For Pollutant Removal From Indoor Air In Vehicule Cabin

SSCI-VIDE+CARE+MHM:PVE:CGUInternational audienceThe photocatalytic process is an efficient method to remove chemical and microbiological pollutants from indoor air in automotive cabin. In the present work, luminous textile was used at first as light source in the photocatalytic degradation of a mixture of pollutants and compared to classical UV lamp. Then, it was used both as light source and a (photo)catalytic support. In this case, the durability and the deposition quality have been optimized in order to preserve good photocatalytic efficiency. This innovative textile combining light source with photocatalyst has advantage of allowing the development of compact reactor with considerable gain of energy

Evaluation of adsorbents for volatile methyl siloxanes sampling based on the determination of their breakthrough volume

AIR:EAU+LLM:CFE:LFI:JMCVolatile methyl siloxanes (VMS) have been detected in many different atmospheres such as biogas, sewage sludge, landfill gas, gasoline and ambient air. In these different atmospheres, their presence can involve several contamination problems and negative effects in industrial processes, their identification and quantification become a real challenge. Up to now there is no standardized procedure for VMS quantification, the sampling step remaining the major obstacle. Sampling gas through sorbent tube followed by analysis on TD-GC-MS is one of the reliable possibilities. It gathers sampling and preconcentration in one step and allows discrimination between all VMS, despite the difficulty to choose the appropriate adsorbent in order to avoid loss of analytes during sampling. In this context, this work deals with the comparison of different types of adsorbents based on the determination of the VMS breakthrough volume (BV). Although Tenax TA is the most widely used adsorbent, experiments show low BV values for the lightest VMS. At 25 degrees C, the BV of TMS and L2 are, respectively, 0.2 and 0.44 L g(-1) which can contribute to an underestimation in concentration during their quantification. Carbosieve SIII usually used for C2-C5, did not adsorb light VMS as it was expected, and breakthrough volume obtained for VMS are more than ten times less than the values obtained for Tenax. On other hand, Chromosorb 106 and Carboxen 1000 in association with Carbotrap C and Carbotrap proved to be appropriated for VMS sampling, due to the high breakthrough volumes obtained for the lightest compounds comparing to the other adsorbents. The BVs of TMS for Carboxen 1000 and Chromosorb 106 are 1.2 x 10(4) and 39 L g(-1), respectively, and 49 x 10(4) and 1142 L g(-1) for L2, respectively. (C) 2013 Elsevier B.V. All rights reserved

TiO2 Coated Luminous Textile : Ideal Photocatalytic System For Pollutant Removal From Indoor Air In Vehicule Cabin

SSCI-VIDE+CARE+MHM:PVE:CGUInternational audienceThe photocatalytic process is an efficient method to remove chemical and microbiological pollutants from indoor air in automotive cabin. In the present work, luminous textile was used at first as light source in the photocatalytic degradation of a mixture of pollutants and compared to classical UV lamp. Then, it was used both as light source and a (photo)catalytic support. In this case, the durability and the deposition quality have been optimized in order to preserve good photocatalytic efficiency. This innovative textile combining light source with photocatalyst has advantage of allowing the development of compact reactor with considerable gain of energy

Towards a better understanding of the impact of VMS on photocatalytic systems

International @ EAU+LLM:JMC:CFE:NSP:LFIInternational audiencePhotocatalytic treatment of air, using TiO2 as the catalyst, is developing more and more because of increasing air pollution which is becoming a serious problem that needs to be addressed immediately. Although deactivation of the photocatalyst is among the most severe practical problems, only few works have been devoted to it, possibly because these catalysts have only recently been commercialized. Usually it is preferred to invest efforts in increasing the efficiency of the treatment rather than fighting against deactivation. In fact, it is much more complicated to carry out treatments under real conditions when compared to the model systems that are traditionally studied. Some of the potentially most important deactivation pollutants are volatile methyl siloxanes (VMS), which are becoming more and more abundant indoors and in ambient air owing to their increased use in personal care products, deodorants, skin care products and as conditioners in hair care products. Octamethylcyclotetrasiloxane (D4) is one such VMS that is highly present in the environment in concentrations ranging from 0.1-10 ľg.m-3 in ambient air and 0.1-100 ľg.m-3 indoors. In this study D4 was chosen as the VMS model, and its photocatalytic oxidation was investigated. Experiments were performed at different D4 concentrations in synthetic air under 40% relative humidity. D4 conversion was measured using TD-GC-MS analysis, while the TiO2 surface was analysed by X-ray photoelectron spectroscopy (XPS). To evaluate the mineralization, a gas chromatograph equipped with a pulsed discharge helium photoionization detector (GC-PDHID) was used. In these conditions at 250 ppbv of D4, the photocatalytic activity was found to decrease with decreasing D4 conversion, from 98% to 30% after 3 days of irradiation, revealing the deactivation of TiO2 accompanied by a yellowish coloration of the media, while total deactivation was observed after three days of irradiation at 500 ppbv of D4. Three photoproducts were identified during D4 degradation: heptamethylhydroxycyclotetrasiloxane, heptamethyl(hydroxymethyl)cyclotetrasiloxane and hexamethylcyclotetrasiloxane. XPS analyses of the media show an increase in Si/Ti ratio and the appearance of an SiOH component, which allows us to better understand the nature of the deposit responsible for the deactivation of TiO2. We also studied the photocatalysis of toluene under the same conditions over three days and a conversion close to 100% was found without any deactivation, hence leading to the confirmation that only D4 contributes to the deactivation of TiO2. Experiments on a binary mixture made up of D4 and toluene are in progress for a better understanding of the impact of VMS impact on photocatalytic systems

Comparison of the photocatalytic efficiency of device based on luminous textile with commercials devices.

SSCI-VIDE+ATARI:CARE+CGU:CML:FDA:CFEInternational audienceNowadays, the indoor air quality has become a major challenge for human health. Actually, a human stay around 90% of a day in closed areas. The vehicle cabin air is concerned by this problem, as people spent the most party of their time in their vehicle (Müller, 2011). Most of the commercial depollution systems are based on adsorption of these compounds to store them. On the opposite, photocatalytic processes, is now recognized as an efficient method to remove organic pollutants present in gaseous phase such as volatile organic compounds (VOCs). However, the development of a compact photocatalytic process is not easy due to the size of the lamp. The aim of the present work is to assess a new concept of automobile cabin air treatment and compare it with commercial device.. This concept is based on the use of luminous textile as support of photocatalyst and as luminous source thank to only one LED to homogeneously irradiate a few hundred square centimeter. . The device was tested in pilot scale using a chamber of 1 m3 with conditions close to reality. The influence of VOC concentrations, and fan velocity on efficiency for two compounds (toluene and formaldehyde) was studied. Finally, the efficiency of this device was compared to the efficiency of commercial devices based on photocatalytic or adsorption process. This work demonstrates the effectiveness of this innovative photocatalytic textile to degrade COVs notably formaldehyde and toluene with regard to existing commercials devices. [1] D. Müller, D. Klingelhöfer, S. Uibel, D. A. Groneberg, (2011) J. Occup. Med. Toxicol, 6, 1701-170

Photocatalytic oxidation of octamethylcyclotetrasiloxane (D4): Towards a better understanding of the impact of volatile methyl siloxanes on photocatalytic systems

AIR:EAU:SURFACES+LLM:CFE:NSP:LFI:JMCPhotocatalytic treatment of air, using TiO2 as the catalyst, is developing more and more because of increasing air pollution which is becoming a serious problem that needs to be addressed immediately. Furthermore Volatile Methyl Siloxanes (VMS) are becoming more and more abundant indoors and in ambient air owing to their increased use in different domain such as cosmetic and personnel care products. Once VMS are present in air, rapid catalyst deactivation can be observed and this reduces the efficiency of the photocatalytic system. In this study octamethylcyclotetrasiloxane D4 was chosen as the VMS model, and its photocatalytic oxidation was investigated. Experiments were performed at various D4 concentrations in synthetic air under 40% relative humidity and D4 conversion was measured using TD-GC-MS analysis, while the TiO2 surface was analyzed by X-ray photoelectron spectroscopy (XPS). Under these conditions at 250 ppbv of D4, the photocatalytic activity as measured by D4 conversion decreased from 98% to 30% after 3 days of irradiation, thus revealing the deactivation of TiO2, and total deactivation was observed after three days of irradiation at 500 ppbv of 04. The photocatalysis of toluene was studied under the same conditions over a period of three days and a conversion close to 100% was found without any deactivation, hence leading to the confirmation that only D4 contributes to the deactivation of TiO2. Additional experiments on a binary mixture of D4 and toluene allowed us to gain a better understanding of the impact of VMS on photocatalytic systems. For the photocatalytic oxidation of D4, three photoproducts were identified, viz. heptamethylhydroxycyclotetrasiloxane, heptamethyl(hydroxymethyl)cyclotetrasiloxane and hexamethylcyclotrisiloxane. XPS analyses of the media show an increase in Si/Ti ratio and the appearance of a SiOH component, which allows us to better understand the nature of the deposit responsible for the deactivation of TiO2. (C) 2014 Elsevier B.V. All rights reserved

Kinetics and mechanism of photocatalytic reforming of glycerol over Pt/TiO2 and Ni/TiO2 photocatalysts

RMN+ECI2D+DLR:CGE:CLO:EPUInternational audienceH2 production from renewable sources is a potential key solution to energetic transition. Glycerol is interesting due to the high H-content. In the present study Pt and Ni supported TiO2 photocatalysts where tested during reforming of alcohol solutions. Combined GC analysis helps to identify intermediates and understand the reaction kinetics

Fibres creuses auto-nettoyantes en PVP-PVDF-TiO2 : évolution des propriétés sous irradiation UV

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