Photocatalytic activity for NO degradation by construction materials: Parametric study and multivariable correlation

Various standards have been published in an effort to rationalize and unify the evaluation and quantification of photocatalytic activity. The experimental conditions stated in the published standards and test methods differ in many aspects that make it very difficult to compare different results. This paper focuses on the influence of the different parameters involved in the photocatalytic process. The photocatalytic active material consists of white mortar, surface coated by TiO2. The activity has been determined by quantifying the photocatalytic oxidation of NO. In the studied concentration interval the kinetics was estimated by a first order reaction. The influence on the activity by the relative humidity, temperature, irradiance, contaminant concentration and catalyst load has been studied. Most influent parameters are the catalyst load and light intensity until reaching plateau values at higher amount and intensity. Humidity influence the activity above 40% RH and an increased temperature lowers the activity. A global empirical correlation, including the mentioned variables, has been developed, allowing the determination of the photocatalytic activity at different environmental conditions (within the constraints of this research) and, when necessary, for comparison with reference conditions

Heavy ion beam measurement of the hydration of cementitious materials

The setting and development of strength of Portland cement concrete depends upon the reaction of water with various phases in the Portland cement. Nuclear resonance reaction analysis (NRRA) involving the 1H(15N,α,γ)12C reaction has been applied to measure the hydrogen depth profile in the few 100 nm thick surface layer that controls the early stage of the reaction. Specific topics that have been investigated include the reactivity of individual cementitious phases and the effects of accelerators and retarders

La nanotecnología en la arquitectura: el grafeno = Nanotechnology in architecture: graphene

La nanotecnología ha favorecido el conocimiento de los materiales a escala nanométrica, tanto en su comportamiento como en su estructura atómica, lo que ha supuesto mejorar numerosos productos y la creación de otros nuevos en casi todas las áreas de la ciencia. Además, su carácter multidisciplinario va a permitir que se aplique en el mundo de la construcción. En este artículo se exponen algunos de los avances nanotecnológicos desarrollados en los materiales de la construcción, dedicando una especial atención a las mejoras que el grafeno ofrece en este campo, gracias a sus magníficas propiedades eléctricas, mecánicas, ópticas, de barrera, etc

Properties of photocatalytic render cement based in globalization age

Today´s cities and the process of urbanization have been associated with significant, economic and social environmental transformations. So, rapid, unplanned or inadequately managed urban expansion leads to rapid sprawl, pollution, and environmental degradation, together with unsustainable production, consumption, and growth patterns. Currently, over half of the world’s population (54%) live in urban ecosystems. Around 90% of the urban population in the EU is exposed to concentrations of air pollutants that WHO considers harmful to health. This asseveration is demonstrated by the latest study on air quality in Europe that has published the EEA. In the other hand, the primary energy use in the built environment accounts for about 40% of total EU energy consumption. Therefore there is a high energy saving potential by minimizing the energy demand for space heating and cooling. In this context, the photocatalysis is also seen as effective as a passive and permanent tool against atmospheric pollution. The use of a photocatalytic render cement based has a high interest in the design of the envelope, due to its contribution to decreasing energy demand by improving comfort in open spaces due to its reflectance. In addition, photocatalysis collaborates to reduce the heat island effect by its self-cleaning and depolluting properties, even in the control of air pollution by high levels of pollens, as shown by the results obtained by Sapiña et al. This paper presents results in an analysis of reflectance, depolluting and self-cleaning properties of photocatalytic cement based render as architectural solution adopted

Properties of photocatalytic render cement based in globalization age

Today´s cities and the process of urbanization have been associated with significant, economic and social environmental transformations. So, rapid, unplanned or inadequately managed urban expansion leads to rapid sprawl, pollution, and environmental degradation, together with unsustainable production, consumption, and growth patterns. Currently, over half of the world’s population (54%) live in urban ecosystems. Around 90% of the urban population in the EU is exposed to concentrations of air pollutants that WHO considers harmful to health. This asseveration is demonstrated by the latest study on air quality in Europe that has published the EEA. In the other hand, the primary energy use in the built environment accounts for about 40% of total EU energy consumption. Therefore there is a high energy saving potential by minimizing the energy demand for space heating and cooling. In this context, the photocatalysis is also seen as effective as a passive and permanent tool against atmospheric pollution. The use of a photocatalytic render cement based has a high interest in the design of the envelope, due to its contribution to decreasing energy demand by improving comfort in open spaces due to its reflectance. In addition, photocatalysis collaborates to reduce the heat island effect by its self-cleaning and depolluting properties, even in the control of air pollution by high levels of pollens, as shown by the results obtained by Sapiña et al. This paper presents results in an analysis of reflectance, depolluting and self-cleaning properties of photocatalytic cement based render as architectural solution adopted