Towards the development of safer by design TiO 2 -based photocatalytic paint: impacts and performances

International audienceAddition of titanium dioxide (TiO 2) (nano)particles into photocatalytic paints represents a promising alternative aiming to mineralize gaseous pollutants, such as volatile organic compounds (VOCs) into innocuous species (H 2 O and CO 2). Despite important industrial and economic benefits, some concerns were raised regarding the risks associated with nano-objects and their human and environmental impacts. To mitigate potential risks associated with the use of these nano-objects, we report a safer by design strategy to develop a photocatalytic paint containing TiO 2 nanoparticles (NPs) taking into consideration the safety aspects over its life cycle. Specific innovative types of TiO 2 NPs were synthesized. These nanoparticles were then incorporated into an organic matrix-based paint. These paints were applied on standard substrates and underwent artificial weathering in an accelerated weathering chamber with controlled parameters. Photocatalytic efficiency towards airborne VOCs was measured for all the paints. Mechanical solicitation through abrasion and incineration tests were performed to assess the potential emission of airborne particles that could lead to human or environmental exposure. In parallel, toxicology studies were conducted to assess the hazards associated with the pristine particles and paint residues. Using this safer by design strategy, we succeeded in decreasing the negative impact of TiO 2 on the paint matrix while keeping a good photocatalytic efficiency and reducing the NP release. Taken together, these results show that we succeeded in generating safer by design paints, thanks to the use of these specifically developed TiO 2 NPs, which exhibit similar photocatalytic properties and enhanced physical properties as compared to paints containing the reference TiO 2 NPs, while reducing their potential hazards

O 18 Brumário, política e pós-modernismo The Eighteenth Brumaire, politics and postmodernism

A maioria das interpretações contemporâneas das análises de Karl Marx sobre a política européia da segunda metade do século XIX têm, em comum, a supressão de toda menção à "economia" e sua substituição, ou pela autonomia da política, nas versões heterodoxas, ou pelo caráter performativo da linguagem, nas versões pós-modernas. Neste artigo, sustenta-se que há n'O 18 Brumário de Luís Bonaparte uma interpretação da política que pode ser reduzida, do ponto de vista teórico, a dois princípios explicativos da concepção materialista da história: a primazia do econômico e a oposição entre essência e aparência. O artigo se propõe a verificar a incidência desses postulados naquele texto.<br>Most contemporary interpretations of Karl Marx's analyses of European politics of the second half of the nineteenth century share both the suppression of all references to the "economy" and its substitution either for the idea of the autonomy of the political (in heterodox views), or for the idea of the performative aspect of language (in post-modern views). This article argues that Marx's Eighteenth Brumaire of Louis Bonapart contains an interpretation of politics that can be reduced, from the theoretical point of view, to two explanatory principles of the materialist conception of history: the primacy of economics, and the opposition between essence and appearance. The article seeks to verify the incidence of these two fundamental propositions within that text

"A Democracy without a People? The Rights of Man in French Contemporary Political Thought"

At the end of the 1970s, philosopher Claude Lefort emphasised - against the excessively restrictive Marxist vision - the political dynamics attached to the affirmation of human rights. This theme has remained predominant in theoretical debate about democracy in France until the present day. A first strand of thought considers the primacy of human rights as a driver of depoliticisation. Authors such as Marcel Gauchet and Pierre Manent have argued that the vitality of the plural society described by Lefort could ultimately backfire on democracy itself. This article argues that this school of thought rests on a narrow conception of rights and an insufficiently dialectical conception of the relationship between rights and practice. Consequently, it defends Lefort's position by relying heavily on a second strand of thought that conceives human rights as the way forward for a radicalisation of democratic ambitions. © 2012 Political Studies Association.SCOPUS: ar.jinfo:eu-repo/semantics/publishe