Showing papers by "André M. Braun published in 2011"

Glossary of terms used in photocatalysis and radiation catalysis (IUPAC Recommendations 2011)

Abstract: This glossary of terms covers phenomena considered under the very wide terms photocatalysis and radiation catalysis. A clear distinction is made between phenomena related to either photochemistry and photocatalysis or radiation chemistry and radiation catalysis. The term "radiation" is used here as embracing electromagnetic radiation of all wavelengths, but in general excluding fast-moving particles. Consistent definitions are given of terms in the areas mentioned above, as well as definitions of the most important parame- ters used for the quantitative description of the phenomena. Terms related to the up-scaling of photocatalytic processes for industrial applications have been included. This Glossary should be used together with the Glossary of terms used in photochemistry, 3 rd edition, IUPAC Recommendations 2006: (doi:10.1351/pac200779030293) as well as with the IUPAC Compendium of Chemical Terminology, 2 nd ed. (the "Gold Book" 2006-; doi:10.1351/gold- book), because many terms used in photocatalysis are defined in these documents.

Radical Photopolymerization in Miniemulsions. Fundamental Investigations and Technical Development

Abstract: A photochemical means to convert acrylate monomer emulsions into polymer nanolatexes has been explored using radical miniemulsion photopolymerization. Our aim is to offer a complete overview through a stepwise mechanistic investigation, addressing first the key aspect of the electronic excitation of the photoinitiator in monomer miniemulsions and ending with the implementation of a photochemical reactor. In a first step, the photon flux absorbed by different photochemical initiators was investigated as a function of the miniemulsion droplet size. A series of miniemulsion polymerizations were also performed and the effects of the primary experimental parameters on the reactions kinetics, molar masses, and colloidal properties were assessed. As expected, droplet size, incident photon flux, and the nature of the photochemical initiator were found to be the primary reaction parameters. Finally, miniemulsion polymerizations were performed in an annular photochemical reactor in batch and semibatch processes.