Technical University of Berlin

About: Technical University of Berlin is a education organization based out in Berlin, Germany. It is known for research contribution in the topics: Laser & Catalysis. The organization has 27292 authors who have published 59342 publications receiving 1414623 citations. The organization is also known as: Technische Universität Berlin & TU Berlin.

Biofilms: an emergent form of bacterial life.

Abstract: Bacterial biofilms are formed by communities that are embedded in a self-produced matrix of extracellular polymeric substances (EPS). Importantly, bacteria in biofilms exhibit a set of 'emergent properties' that differ substantially from free-living bacterial cells. In this Review, we consider the fundamental role of the biofilm matrix in establishing the emergent properties of biofilms, describing how the characteristic features of biofilms - such as social cooperation, resource capture and enhanced survival of exposure to antimicrobials - all rely on the structural and functional properties of the matrix. Finally, we highlight the value of an ecological perspective in the study of the emergent properties of biofilms, which enables an appreciation of the ecological success of biofilms as habitat formers and, more generally, as a bacterial lifestyle.

Biofibres, biodegradable polymers and biocomposites: An overview

Abstract: Recently the critical discussion about the preservation of natural resources and recycling has led to the renewed interest concerning biomaterials with the focus on renewable raw materials. Because of increasing environmental consciousness and demands of legislative authorities, use and removal of traditional composite structures, usually made of glass, carbon or aramid fibers being reinforced with epoxy, unsaturated polyester, or phenolics, are considered critically. Recent advances in natural fiber development, genetic engineering and composite science offer significant opportunities for improved materials from renewable resources with enhanced support for global sustainability. The important feature of composite materials is that they can be designed and tailored to meet different requirements. Since natural fibers are cheap and biodegradable, the biodegradable composites from biofibers and biodegradable polymers will render a contribution in the 21st century due to serious environmental problem. Biodegradable polymers have offered scientists a possible solution to waste-disposal problems associated with traditional petroleum-derived plastics. For scientists the real challenge lies in finding applications which would consume sufficiently large quantities of these materials to lead price reduction, allowing biodegradable polymers to compete economically in the market. Today's much better performance of traditional plastics are the outcome of continued RD however the existing biodegradable polymers came to public only few years back. Prices of biodegradable polymers can be reduced on mass scale production; and such mass scale production will be feasible through constant R&D efforts of scientists to improve the performance of biodegradable plastics. Manufacture of biodegradable composites from such biodegradable plastics will enhance the demand of such materials. The structural aspects and properties of several biofibers and biodegradable polymers, recent developments of different biodegradable polymers and biocomposites are discussed in this review article. Collaborative R&D efforts among material scientists and engineers as well as intensive co-operation and co-ordination among industries, research institutions and government are essential to find various commercial applications of biocomposites even beyond to our imagination.

Lattice-strain control of the activity in dealloyed core–shell fuel cell catalysts

Abstract: Electrocatalysis will play a key role in future energy conversion and storage technologies, such as water electrolysers, fuel cells and metal-air batteries. Molecular interactions between chemical reactants and the catalytic surface control the activity and efficiency, and hence need to be optimized; however, generalized experimental strategies to do so are scarce. Here we show how lattice strain can be used experimentally to tune the catalytic activity of dealloyed bimetallic nanoparticles for the oxygen-reduction reaction, a key barrier to the application of fuel cells and metal-air batteries. We demonstrate the core-shell structure of the catalyst and clarify the mechanistic origin of its activity. The platinum-rich shell exhibits compressive strain, which results in a shift of the electronic band structure of platinum and weakening chemisorption of oxygenated species. We combine synthesis, measurements and an understanding of strain from theory to generate a reactivity-strain relationship that provides guidelines for tuning electrocatalytic activity.