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671.
Dr. Bernhard von Vacano Dr. Hannah Mangold Dr. Guido W. M. Vandermeulen Dr. Glauco Battagliarin Dr. Maximilian Hofmann Dr. Jessica Bean Dr. Andreas Künkel 《Angewandte Chemie (International ed. in English)》2023,62(12):e202210823
To achieve a sustainable circular economy, polymer production must start transitioning to recycled and biobased feedstock and accomplish CO2 emission neutrality. This is not only true for structural polymers, such as in packaging or engineering applications, but also for functional polymers in liquid formulations, such as adhesives, lubricants, thickeners or dispersants. At their end of life, polymers must be either collected and recycled via a technical pathway, or be biodegradable if they are not collectable. Advances in polymer chemistry and applications, aided by computational material science, open the way to addressing these issues comprehensively by designing for recyclability and biodegradability. This Review explores how scientific progress, together with emerging regulatory frameworks, societal expectations and economic boundary conditions, paint pathways for the transformation towards a circular economy of polymers. 相似文献
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Dr. Eduardo Anaya-Plaza Jan Joseph Stefan Bauroth Maximilian Wagner Dr. Christian Dolle Dr. Michael Sekita Prof. Franziska Gröhn Prof. Erdmann Spiecker Prof. Timothy Clark Dr. Andrés de la Escosura Prof. Dirk M. Guldi Prof. Tomás Torres 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(42):18946-18955
675.
Christian Heckl Maximilian Aumiller Adrian Rühm Ronald Sroka Herbert Stepp 《Photochemistry and photobiology》2020,96(2):388-396
In interstitial photodynamic therapy, light is distributed to the tumor via light diffusers. The light dose and the related phototoxic effect achieved throughout the target volume critically depend on absorption, scattering and diffuser positioning. Using liquid tissue phantoms, we investigated the dependencies of treatment light transmission and protoporphyrin IX (PpIX) fluorescence on these parameters. This enabled monitoring hemoglobin oxygenation and methemoglobin formation during irradiation (635 nm, 200 mW cm−1 diffuser length). Starting with two parallel cylindrical diffusers at 10 mm radial separation, the light transmitted between the fibers was largely determined by the minimal distance between the diffusers, but rather insensitive to an additional axial displacement or tilting of one fiber with respect to the other. For fixed distance between the diffusor centers, however, tilting up to direct contact resulted in a 10-fold signal increase. For hemoglobin within erythrocytes, irradiation leads to photobleaching of PpIX without marked change in hemoglobin oxygenation until hemolysis occurs. Afterward, hemoglobin is rapidly deoxygenized and methemoglobin is formed, leading to a dramatic increase in absorption. For lysed blood, these effects start immediately. A comparison of intraoperative monitoring of the signals with the experimental results might help prevent insufficient treatment by reconsidering treatment planning or prolonging irradiation. 相似文献
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Marcel Krug Maximilian Wagner Dr. Tobias A. Schaub Dr. Wen-Shan Zhang Christoph M. Schüßlbauer Johannes D. R. Ascherl Dr. Peter W. Münich Prof. Dr. Rasmus R. Schröder Prof. Dr. Franziska Gröhn Prof. Dr. Pavlo O. Dral Prof. Dr. Mario Barbatti Prof. Dr. Dirk M. Guldi Prof. Dr. Milan Kivala 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):16368-16376
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Torsten Thiess Guillaume Blanger‐Chabot Felipe Fantuzzi Maximilian Michel Moritz Ernst Bernd Engels Holger Braunschweig 《Angewandte Chemie (International ed. in English)》2020,59(36):15480-15486
Herein we describe the first examples of isolable electron‐precise diboranes(4) that bear azide moieties: the acyclic 1,2‐diazido‐1,2‐bis(dimethylamino)diborane(4) and the cyclic 1,4‐diaryl‐2,3‐diazido‐1,4‐diaza‐2,3‐diborinines (aryl=mesityl, 2,6‐xylyl, 4‐tolyl). The reported examples are not only stable enough to be observed and isolated (putative transient diborane(4) azides previously reported by our group spontaneously decompose even below room temperature), but some of them are even robust enough to undergo controlled pyrolysis without explosive decomposition at temperatures well above 100 °C. In two cases, the controlled pyrolysis allows the isolation of complex diazaboretidines, which are the apparent dimerization products of endocyclic boryl‐iminoboranes. 相似文献
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Malina Bilo Maximilian Münzner Christian Küster Prof. Dirk Enke Dr. Young Joo Lee Prof. Michael Fröba 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(49):11220-11230
Herein, it is reported how pseudomorphic transformation of divinylbenzene (DVB)-bridged organosilica@controlled pore glasses (CPG) offers the possibility to generate hierarchically porous organosilica/silica hybrid materials. CPG is utilized to provide granular shape/size and macroporosity and the macropores of the CPG is impregnated with organosilica phase, forming hybrid system. By subsequent pseudomorphic transformation, an ordered mesopore phase is generated while maintaining the granular shape and macroporosity of the CPG. Surface areas and mesopore sizes in the hierarchical structure are tunable by the choice of the surfactant and transformation time. Two-dimensional magic angle spinning (MAS) NMR spectroscopy demonstrated that micellar-templating affects both organosilica and silica phases and pseudomorphic transformation induces phase transition. A double-layer structure of separate organosilica and silica layers is established for the impregnated material, while a single monophase consisting of randomly distributed T and Q silicon species at the molecular level is identified for the pseudomorphic transformed materials. 相似文献