Improving the Mechanical Properties and Tribological Behavior of Sulfobetaine Polyurethane Based on Hydrophobic Chains to Be Applied as Artificial Meniscus.

In the context of meniscus reconstruction in knee joints, current bulk biomaterials fail to meet the clinical demands for both excellent mechanical strength and low coefficient of friction. In this research, zwitterionic polyurethanes (PUs) with varying sulfobetaine (SB) groups were synthesized as the potential materials for artificial meniscus to investigate the relationship between the structures of SB groups and the performances of PUs. Under the saturation condition of 3 mg/mL hyaluronic acid aqueous solution, PU with long-alkyl chains and SB groups (PU-hSB4) exhibited a good tensile modulus (111.

Structural Analysis and Intrinsic Enzyme Mimicking Activities of Ligand-Free PtAg Nanoalloys.

Nanozymes are nanomaterials with biocatalytic properties under physiological conditions and are one class of artificial enzymes to overcome the high cost and low stability of natural enzymes. However, surface ligands on nanomaterials will decrease the catalytic activity of the nanozymes by blocking the active sites. To address this limitation, ligand-free PtAg nanoclusters (NCs) are synthesized and applied as nanozymes for various enzyme-mimicking reactions.

Engineering PtCu nanoparticles for a highly efficient methanol electro-oxidation reaction.

Achieving a highly efficient and durable methanol electro-oxidation catalyst in acid media is critical for the practical utilization of direct methanol fuel cells (DMFCs) at the commercial scale. Herein, we report a facile and effective one-pot strategy for the synthesis of carbon-supported PtCu alloy nanoparticles (PtCu NPs) with a Pt-rich surface, small particle size and uniform dispersion. The as-prepared PtCu NPs with the optimal alloy composition (PtCu) exhibit a significantly improved electrochemical methanol oxidation reaction performance in terms of a high activity, superior CO tolerance and remarkable durability, in contrast to those of commercial Pt/C catalysts in acid media.

Carbon-Supported Divacancy-Anchored Platinum Single-Atom Electrocatalysts with Superhigh Pt Utilization for the Oxygen Reduction Reaction.

Maximizing the platinum utilization in electrocatalysts toward oxygen reduction reaction (ORR) is very desirable for large-scale sustainable application of Pt in energy systems. A cost-effective carbon-supported carbon-defect-anchored platinum single-atom electrocatalysts (Pt /C) with remarkable ORR performance is reported. An acidic H /O single cell with Pt /C as cathode delivers a maximum power density of 520 mW cm at 80 °C, corresponding to a superhigh platinum utilization of 0.

A Bifunctional Highly Efficient FeN /C Electrocatalyst.

Herein, a type of Fe, N-codoped carbon electrocatalyst (FeN /C, Fe-N-BCNT#BP) containing bamboo carbon nanotubes and displaying bifunctional high catalytic efficiency for both oxygen reduction reaction (ORR) and carbon dioxide reduction reaction (CO2RR) is reported. It shows high electrocatalytic activity and stability for both the ORR process with onset potential of 1.03 V in alkaline and the CO2RR to CO with high faradic efficiency up to 90% and selectivity of about 100% at low overpotential of 0.

Growth mechanism deconvolution of self-limiting supraparticles based on microfluidic system.

The synthesis of colloidal supraparticles (SPs) based on self-assembly of nanoscopic objects has attracted much attention in recent years. Here, we demonstrate the formation of self-limiting monodisperse gold SPs with core-shell morphology based on the building blocks of flexible nanoarms in one step. A flow-based microfluidic chip is utilized to slow down the assembly process of the intermediates, which surprisingly allows for observation of ultrathin gold nanoplates as first intermediates.

Theoretical study of resorufin reduction mechanism by NaBH4.

In the current work, the whole reduction mechanism of resorufin by sodium borohydride (NaBH4) has been investigated completely using quantum chemical theory for the first time. The possible pathways for each step were considered as much as possible. The calculated results reveal that the reduction mechanism for resorufin undergoes a nucleophilic addition with BH4(-), a synchronous proton abstraction from a carbon (C) atom, a protonation in a nitrogen (N) atom, and then a final hydrolysis process to obtain final reduced product dihydroresorufin.

Single-molecule chemical reaction reveals molecular reaction kinetics and dynamics.

Understanding the microscopic elementary process of chemical reactions, especially in condensed phase, is highly desirable for improvement of efficiencies in industrial chemical processes. Here we show an approach to gaining new insights into elementary reactions in condensed phase by combining quantum chemical calculations with a single-molecule analysis. Elementary chemical reactions in liquid-phase, revealed from quantum chemical calculations, are studied by tracking the fluorescence of single dye molecules undergoing a reversible redox process.

catena-Poly[[[tetra-aqua-zinc(II)]-μ-4,4'-bipyridine-κN:N'] benzene-1,4-di-carboxyl-ate].

In the title compound, {[Zn(C(10)H(8)N(2))(H(2)O)(4)](C(8)H(4)O(4))}(n), the Zn(II) atoms, lying on a twofold rotation axis, are bridged by 4,4'-bipyridine ligands, resulting in a linear chain along the b axis. In the chain, the Zn(II) atom adopts a slightly distorted octa-hedral coordination geometry involving four water mol-ecules at the equatorial positions. The noncoordinated benzene-1,4-dicarboxyl-ate anion, which is also located on a twofold rotation axis, bridges adjacent chains through O-H⋯O hydrogen bonds, forming a three-dimensional supra-molecular network.