Self‐assembly Mechanism and Chiral Transfer in CuO Superstructures

Chiral inorganic superstructures have received considerable interest due to the chiral communication between inorganic compounds and chiral organic additives. However, the demanding fabrication and complex multilevel structure seriously hinder the understanding of chiral transfer and self‐assembly mechanisms. Herein, we use chiral CuO superstructures as a model system to study the formation process of hierarchical chiral structures. Based on a simple and mild synthesis route, the time‐resolved morphology and the in situ chirality evolution could be easily followed. The morphology evolution of the chiral superstructure involves hierarchical assembly, including primary nanoparticles, intermediate bundles, and superstructure at different growth stages. Successive redshifts and enhancements of the CD signal support chiral transfer from the surface penicillamine to the inorganic superstructure. Full‐field electro‐dynamical simulations reproduced the structural chirality and allowed us to predict its modulation. This work opens the door to a large family of chiral inorganic materials where chiral molecule‐guided self‐assembly can be specifically designed to follow a bottom‐up chiral transfer pathway.National Natural Science Foundation of China http://dx.doi.org/10.13039/501100001809Helmholtz-OCPC Postdoc ProgramPeer Reviewe

Thermosensitive Cu2O-PNIPAM core-shell nanoreactors with tunable photocatalytic activity

We report a facile and novel method for the fabrication of Cu2O@PNIPAM core-shell nanoreactors using Cu2O nanocubes as the core. The PNIPAM shell not only effectively protects the Cu2O nanocubes from oxidation, but also improves the colloidal stability of the system. The Cu2O@PNIPAM core-shell microgels can work efficiently as photocatalyst for the decomposition of methyl orange under visible light. A significant enhancement in the catalytic activity has been observed for the core-shell microgels compared with the pure Cu2O nanocubes. Most importantly, the photocatalytic activity of the Cu2O nanocubes can be further tuned by the thermosensitive PNIPAM shell, as rationalized by our recent theory.Comment: 8 pages, 6 figures (Supporting Information included: 11 pages, 10 figures

Poly(ethylene glycol) brush-b-poly(N-vinylpyrrolidone)-based double hydrophilic block copolymer particles crosslinked via crystalline α-cyclodextrin domains

Self-assembly of block copolymers is a significant area of polymer science. The self-assembly of completely water-soluble block copolymers is of particular interest, albeit a challenging task. In the present work the self-assembly of a linear-brush architecture block copolymer, namely poly(N-vinylpyrrolidone)-b-poly(oligoethylene glycol methacrylate) (PVP-b-POEGMA), in water is studied. Moreover, the assembled structures are crosslinked via α-CD host/guest complexation in a supramolecular way. The crosslinking shifts the equilibrium toward aggregate formation without switching off the dynamic equilibrium of double hydrophilic block copolymer (DHBC). As a consequence, the self-assembly efficiency is improved without extinguishing the unique DHBC self-assembly behavior. In addition, decrosslinking could be induced without a change in concentration by adding a competing complexation agent for α-CD. The self-assembly behavior was followed by DLS measurement, while the presence of the particles could be observed via cryo-TEM before and after crosslinking

A General Synthetic Route Towards Highly Dispersed Metal Clusters Enabled by Poly ionic liquid s

The ability to synthesize a broad spectrum of metal clusters MCs with their size controllable on a subnanometer scale presents an enticing prospect for exploring nanosize dependent properties. Here we report an innovative design of a capping agent from a polytriazolium poly ionic liquid PIL in a vesicular form in solution that allows for crafting a variety of MCs including transition metals, noble metals, and their bimetallic alloy with precisely controlled sizes amp; 8764;1 nm and record high catalytic performance. The ultrastrong stabilization power is a result of an unusual synergy between the conventional binding sites in the heterocyclic cations in PIL and an in situ generated polycarbene structure induced simultaneously to the reduction reactio

Quality of Service-aware matchmaking for adaptive microservice-based applications

Applications that make use of Internet of Things (IoT) can capture an enormous amount of raw data from sensors and actuators, which is frequently transmitted to cloud data centers for processing and analysis. However, due to varying and unpredictable data generation rates and network latency, this can lead to a performance bottleneck for data processing. With the emergence of fog and edge computing hosted microservices, data processing could be moved towards the network edge. We propose a new method for continuous deployment and adaptation of multi-tier applications along edge, fog, and cloud tiers by considering resource properties and non-functional requirements (e.g., operational cost, response time and latency etc.). The proposed approach supports matchmaking of application and Cloud-To-Things infrastructure based on a subgraph pattern matching (P-Match) technique. Results show that the proposed approach improves resource utilization and overall application Quality of Service. The approach can also be integrated into software engineering workbenches for the creation and deployment of cloud-native applications, enabling partitioning of an application across the multiple infrastructure tiers outlined above

Nonclassical Crystallization Pathway of Transition Metal Phosphate Compounds

Here, we elucidate nonclassical multistep crystallization pathways of transition metal phosphates from aqueous solutions. We followed precipitation processes of M-struvites, NH4MPO4·6H2O, and M-phosphate octahydrates, M3(PO4)2·8H2O, where M = Ni, Co, or NixCo1-x, by using in situ scattering and spectroscopy-based techniques, supported by elemental mass spectrometry analyses and advanced electron microscopy. Ni and Co phosphates crystallize via intermediate colloidal amorphous nanophases, which change their complex structures while agglomerating, condensing, and densifying throughout the extended reaction times. We reconstructed the three-dimensional morphology of these precursors by employing cryo-electron tomography (cryo-ET). We found that the complex interplay between metastable amorphous colloids and protocrystalline units determines the reaction pathways. Ultimately, the same crystalline structure, such as struvite, is formed. However, the multistep process stages vary in complexity and can last from a few minutes to several hours depending on the selected transition metal(s), their concentration, and the Ni/Co ratio.</p

Poly(ionic liquid) nanovesicles via polymerization induced self-assembly and their stabilization of Cu nanoparticles for tailored CO2 electroreduction

Herein, we report a straightforward, scalable synthetic route towards poly(ionic liquid) (PIL) homopolymer nanovesicles (NVs) with a tunable particle size of 50 to 120 nm and a shell thickness of 15 to 60 nm via one-step free radical polymerization induced self-assembly. By increasing monomer concentration for polymerization, their nanoscopic morphology can evolve from hollow NVs to dense spheres, and finally to directional worms, in which a multilamellar packing of PIL chains occurred in all samples. The transformation mechanism of NVs’ internal morphology is studied in detail by coarse-grained simulations, revealing a correlation between the PIL chain length and the shell thickness of NVs. To explore their potential applications, PIL NVs with varied shell thickness are in situ functionalized with ultra-small (1 ∼ 3 nm in size) copper nanoparticles (CuNPs) and employed as electrocatalysts for CO2 electroreduction. The composite electrocatalysts exhibit a 2.5-fold enhancement in selectivity towards C1 products (e.g., CH4), compared to the pristine CuNPs. This enhancement is attributed to the strong electronic interactions between the CuNPs and the surface functionalities of PIL NVs. This study casts new aspects on using nanostructured PILs as new electrocatalyst supports in CO2 conversion to C1 products

Correction Three dimensional protein assemblies directed by orthogonal non covalent interactions

In this report, an orthogonal non covalent interaction strategy based on specific recognition between sugar and protein, and host guest interaction, was employed to construct artificial three dimensional 3D protein assemblies in the laborator

Spherical Polyelectrolyte Brushes Templated Hollow C MnO Nanospheres as Sulfur Host Materials for Li S Batteries

Li amp; 8722;S battery has been considered as the next generation energy storage device, which still suffers from the shuttle effect of lithium polysulfides LiPSs . In this work, mesoporous hollow carbon coated MnO nanospheres C MnO have been designed and synthesized using spherical polyelectrolyte brushes SPB as template, KMnO4 as MnO precursor, and polydopamine as carbon source to improve the electrochemical performance of Li amp; 8722;S battery. The hollow C MnO nanospheres enable the combination of physical confinement and chemical adsorption of the LiPSs. The thin carbon coating layer can provide good electrical conductivity and additional physical confinement to polysulfides. Moreover, the encapsulated MnO inside the carbon shell exhibits strong chemical adsorption to polysulfides. The constructed C MnO S cathode shows the discharge capacity of 1026 amp; 8197;mAh amp; 8201;g amp; 8722;1 at 0.1 amp; 8197;C with 79 capacity retention after 80 cycles. The synthesized hollow C MnO nanoparticles can work as highly efficient sulfur host materials, providing an effective solution to suppress the shuttle effect in Li amp; 8722;S batter