The photocatalytic CO2 reduction reaction (CRR) represents a promising route for the clean utilization of stranded renewable resources, but poor selectivity resulting from the competing hydrogen evolution reaction (HER) in aqueous solution limits its practical applicability. In the present contribution a photocatalyst with hydrophobic surfaces was fabricated. It facilitates an efficient three‐phase contact of CO2 (gas), H2O (liquid), and catalyst (solid). Thus, concentrated CO2 molecules in the gas phase contact the catalyst surface directly, and can overcome the mass‐transfer limitations of CO2, inhibit the HER because of lowering proton contacts, and overall enhance the CRR. Even when loaded with platinum nanoparticles, one of the most efficient HER promotion cocatalysts, the three‐phase photocatalyst maintains a selectivity of 87.9 %. Overall, three‐phase photocatalysis provides a general and reliable method to enhance the competitiveness of the CRR.
Covalent bridges play a crucial role in the folding process of sequence-defined biopolymers. This feature, however, has not been recreated in synthetic polymers because, apart from some simple regular arrangements (such as block co-polymers), these macromolecules generally do not exhibit a controlled primary structure--that is, it is difficult to predetermine precisely the sequence of their monomers. Herein, we introduce a versatile strategy for preparing foldable linear polymer chains. Well-defined polymers were synthesized by the atom transfer radical polymerization of styrene. The controlled addition of discrete amounts of protected maleimide at precise times during the synthesis enabled the formation of polystyrene chains that contained positionable reactive alkyne functions. Intramolecular reactions between these functions subsequently led to the formation of different types of covalently folded polymer chains. For example, tadpole (P-shaped), pseudocyclic (Q-shaped), bicyclic (8-shaped) and knotted (α-shaped) macromolecular origamis were prepared in a relatively straightforward manner.
Dynamic and adaptive materials are powerful constructs in macromolecular and polymer chemistry with a wide array of applications in drug delivery, bioactive systems, and self‐healing materials. Very often, dynamic materials are based on carefully tailored cyclodextrin host–guest interactions. The precise incorporation of these host and guest moieties into macromolecular building blocks allows the formation of complex macromolecular structures with predefined functions. Thus, dynamic materials with extraordinary adaptive property profiles—responsive to thermal, chemical, and photonic fields—become accessible. This Review explores the hierarchical formation of dynamic materials and complex macromolecular structures from the molecular via the macromolecular to the colloidal and macroscopic level, with a specific emphasis on the functionality and responsiveness of the assemblies, specifically in biological contexts.
A versatile strategy is reported for the multi-gram synthesis of discrete oligomers from commercially available monomer families, e.g., acrylates, styrenics, siloxanes. Central to this strategy is the identification of reproducible procedures for the separation of oligomer mixtures using automated flash chromatography systems with the effectiveness of this approach demonstrated through the multi-gram preparation of discrete oligomer libraries (Đ = 1.0). Synthetic availability, coupled with accurate structural control, allows these functional building blocks to be harnessed for both fundamental studies as well as targeted technological applications.
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