Peinture (matière) | EPFL Graph Search

La peinture désigne à la fois une composition généralement liquide employée pour protéger ou décorer la surface d'un objet en le couvrant d'une pellicule opaque ou colorée , et la couche mince résultant de cette application . Une peinture se compose essentiellement d'un liant, liquide avant l'application, solide après, et d'un ou plusieurs pigments pulvérulents qui lui confèrent sa couleur et son opacité. Le solvant ou le diluant qui règle la fluidité du mélange s'évapore au séchage. Des adjuvants permettent de faciliter la mise en œuvre, d'améliorer la conservation, d'ajuster l'aspect brillant ou mat de la peinture sèche. La distinction entre peintures et encres est principalement d'usage, certaines encres ayant la même composition que des peintures . Utilisation Fonctions La peinture a le plus souvent une fonction de protection des matériaux. Elle protège les métaux contre la corrosion, les bois contre les atteintes biologiques (). Elle forme une couche min

Biocides in paints in urban areas: Modelling an underestimated source of environmental contamination

David Andrew Barry, Sylvain Coutu, Luca Rossi, Chiara Rota

Biocide contamination of receiving waters is generally linked with agriculture. However, recent studies have shown that urban contributions should be also considered. One of the suspected biocide sources in the urban environment is building paint. Biocides like diuron, irgarol, terbutryn, carbendazim, etc., are conventionally used in paint to control fungi, algae, bacteria and other microorganisms that can colonize building façades. The problem of biocides in urban areas is closely linked to meteorological conditions and in particular to rain events. As a consequence, it is important to understand how rainwater collects and transports biocides from façades and how these biocides are transported in sewer systems to receiving waters. In this study, we present a conceptual model describing façade leaching and couple it with a Wind Driven Rain model and a classical hydrological model to compute the contribution of a city to the biocide load from building paint. For the entire city of Lausanne (Switzerland, 200’000 inhabitants), a global production of 2200 kg/year of terbutryn leached by rain was estimated considering local building characteristics and meteorological information. The leaching model fitted well the peak in concentration measured at the bottom of the wall at the initial stage of the rain event. However, concentrations measured in an urban river in the watershed leads to the conclusion that most of this leachate does not reach directly receiving waters, but is infiltrated into soil or reaches the sewers after some delays in drainage pipes. Release of biocides from façade leaching in the environment is systematic during rain event. It is of greater importance to estimate the dynamic of biocides during rain events and to compare these values with dedicated time varying environmental quality criteria.

2011

Modelling city-scale facade leaching of biocide by rainfall

David Andrew Barry, Sylvain Coutu, Luca Rossi, Chiara Rota

A methodology is presented for estimating, at the city scale, the amount of biocide released from facades during rain events. The methodology consists of two elements. First, leaching of a single facade is simulated using a two-region model, one region for the biocide in the facade and the other for that in the flow over the facade surface. In the latter region, water advection moves the biocide to the base of the facade, and so into the environment. Rates of detachment and deposition define the exchange process between the two regions. The two-region model was calibrated on laboratory data, and afterward applied at city scale to Lausanne, Switzerland (200,000 inhabitants). The city-scale application uses the second element of the methodology, which consists of an estimate of the exposure of the city’s facades to rainfall, and relating that rainfall to the overfacade flow in the calibrated single-facade model. This results in a straightforward translation of over-facade flow volume to facade paint age, a necessary connection since facade leaching is dependent on paint age. For Lausanne, it was estimated that approximately 30% of the mass of biocides applied annually is released into the environment

Elsevier2012

Waveguide-PAINT offers an open platform for large field-of-view super-resolution imaging

Anna Archetti, Evgenii Glushkov, Suliana Manley, Aleksandra Radenovic, Anton Stroganov

Super-resolution microscopies based on the localization of single molecules have been widely adopted due to their demonstrated performance and their accessibility resulting from open software and simple hardware. The PAINT method for localization microscopy offers improved resolution over photoswitching methods, since it is less prone to sparse sampling of structures and provides higher localization precision. Here, we show that waveguides enable increased throughput and data quality for PAINT, by generating a highly uniform similar to 100 x 2000 mu m(2) area evanescent field for TIRF illumination. To achieve this, we designed and fabricated waveguides optimized for efficient light coupling and propagation, incorporating a carefully engineered input facet and taper. We also developed a stable, low-cost microscope and 3D-printable waveguide chip holder for easy alignment and imaging. We demonstrate the capabilities of our open platform by using DNA-PAINT to image multiple whole cells or hundreds of origami structures in a single field of view.

2019

Biocides in paints in urban areas: Modelling an underestimated source of environmental contamination

David Andrew Barry, Sylvain Coutu, Luca Rossi, Chiara Rota

2011