A post curing strategy toward the feasible covalent adaptable networks in polyacrylate latex films

The implementation of covalent adaptable networks (CANs) in general resin system is becoming attractive. In this work, we propose a simple post-curing strategy based on the core-shell structured acrylate latex for the achievement on both the improved general performance and the CANs characteristics in latex films. The building to the CANs was relied on the introduction of 4,4′-diaminophenyl disulfide as the curing agent, which cured the acetoacetoxy decorated shell polymer through the ketoamine reaction. The metathesis reaction of aromatic disulfides in the crosslinking segments enabled the thermally induced dynamic behavior of the network as revealed in the stress relaxation tests by comparison with other diamine crosslinking agents without the incorporation of disulfide. The synergism of the dynamic crosslinking of the shell polymer and static crosslinking in the core polymer contributed to the improved mechanical strength (15 MPa, strain% = 250%) and the suppressed water adsorption (~1% in 24 h of soaking) of the latex film, which exhibited above 90% of recovery in both strength and strain from a cut-off film damage within 1 h at 80°C. Moreover, the cured latex film could be recycled, and 75% of the mechanical performance was regained after three fragmentation-hot-pressing cycles. These, in addition with the feasible and environmental friendly characteristics, suggest a sustainable paradigm toward the smart thermosetting latex polymers.     

Hybrid EuIII Coordination Luminophore Standing on Two Legs on Silica Nanoparticles for Enhanced Luminescence

In this study, we have demonstrated a two-legged, upright molecular design method for monochromatic and bright red luminescent Ln^III-silica nanomaterials. A novel Eu^III-silica hybrid nanoparticle was developed by using a doubly binding TPPO−Si(OEt)₃ (TPPO: triphenyl phosphine oxide) linker. The TPPO−Si(OEt)₃ was confirmed by ¹H, ³¹P, ²⁹Si NMR spectroscopy and single-crystal X-ray analysis. Luminescent Eu(hfa)₃ and Eu(tfc)₃ moieties (hfa: hexafluoroacetylacetonate, tfc: 3-(trifluoromethylhydroxymethylene)camphorate) were fixed onto TPPO−Si(OEt)₃-modified silica nanoparticles, producing Eu(hfa)₃(TPPO−Si)₂-SiO₂ and Eu(tfc)₃(TPPO−Si)₂-SiO₂, respectively. Eu(hfa)₃(TPPO−Si)₂−SiO₂ exhibited the higher intrinsic luminescence quantum yield (93 %) and longer emission lifetime (0.98 ms), which is much larger than those of previously reported Eu^III-based hybrid materials. Eu(tfc)₃(TPPO−Si)₂−SiO₂ showed an extra-large intrinsic emission quantum yield (54 %), although the emission quantum yield for the precursor Eu(tfc)₃(TPPO−Si(OEt)₃)₂ was found to be 39 %. These results confirmed that the TPPO−Si(OEt)₃ linker is a promising candidate for development of Eu^III-based luminescent materials.     

Improved Initial Charging Capacity of Na-poor Na0.44MnO2 via Chemical Presodiation Strategy for Low-cost Sodium-ion Batteries

Sodium-ion batteries(SIBs)are promising for grid-scale energy storage applications due to the natural abundance and low cost of sodium.Among various Na insertion cathode materials,Na0.44MnO2 has attracted the most attention because of its cost effectiveness and structural stability.However,the low initial charge capacity for Na-poor Na0.44MnO2 hinders its practical applications.Herein,we developed a facile chemical presodiated method using sodiated biphenly to transform Na-poor Na0.44MnO2 into Na-rich Na0.66MnO2.After presodiation,the initial charge capacity of Na0.44MnO2 is greatly enhanced from 56.5 mA·h/g to 115.7 mA·h/g at 0.1 C(1 C=121 mA/g)and the excellent cycling stability(the capacity retention of 94.1%over 200 cycles at 2 C)is achieved.This presodiation strategy would open a new avenue for promoting the practical applications of Na-poor cathode materials in sodium-ion batteries.     

6-硫杂-13-氧杂二环[9.3.0]-3,8-二炔十四烷的合成及核磁共振鉴定

以３，４－二（４′－甲磺酰氧－２′－丁炔基）四氢呋喃或６－硫杂－３，８－二炔－１，１１－二羟甲基环十一烷为原料合成了二环化合物６－硫杂－１３－氧杂二环［９．３．０］－３，８－二炔十四烷。通过１ＨＮＭＲ，１３ＣＮＭＲ，ＩＲ及ＭＳ进行了结构鉴定。     

Metabolomics Provides A Novel Interpretation of the Changes in Main Compounds during Black Tea Processing through Different Drying Methods

This study aimed to compare the effect of hot roller (HR) drying and hot air (HA) drying on the sensory evaluation, chemical quality, antioxidant activity, and metabolic profile of Yihong Congou black tea processed from E’cha NO1. The Yihong Congou black tea dried with HA obtained higher sensory scores and better chemical qualities such as the hue of tea brew color (a and b), content of theaflavins, thearubigins, water extract, free amino acids, tea polyphenol, and the ratio of polyphenol to amino acids as well as higher antioxidant capacities compared to that dried with HR. The HA drying tea increased the contents of volatile compounds that had positive correlation with sweet and flowery flavor, while the HR drying tea increased the contents of volatile compounds related to fruity flavor. Moreover, non-targeted metabolomics data indicated that the levels of most free amino acids significantly increased, while the levels of most soluble sugars reduced in the HA drying method compared to the HR drying method. The metabolic analysis was also consistent with the above results and revealed that D-ribose and gallic acid were the main characteristic metabolites of HA drying. Our results could provide a technical reference and theoretical guide to processing a high quality of Yihong Congou black tea.     

Anti-Hyperglycemic Effects of Refined Fractions from Cyclocarya paliurus Leaves on Streptozotocin-Induced Diabetic Mice

To identify the chemical components responsible for the anti-hyperglycemic effect of Cyclocarya paliurus (Batal.) Iljinsk (Juglandaceae) leaves, an ethanol extract (CPE) and a water extract (CPW) of C. paliurus leaves, as well as their total flavonoids (CPF), triterpenoids (CPT) and crude polysaccharides (CPP), were prepared and assessed on streptozotocin (STZ)-induced diabetic mice. After being orally administrated once a day for 24 days, CPF (300 mg/kg), CPP (180 mg/kg), or CPF+CPP (300 mg/kg CPF + 180 mg/kg CPP) treatment reversed STZ-induced body weight and muscle mass losses. The glucose tolerance tests and insulin tolerance tests suggested that CPF, CPP, and CPF+CPP showed anti-hyperglycemic effect in STZ-induced diabetic mice. Furthermore, CPF enhances glucose-stimulated insulin secretion in MIN6 cells and insulin-stimulated glucose uptake in C2C12 myotubes. CPF and CPP suppressed inflammatory cytokine levels in STZ-induced diabetic mice. Additionally, CPF and CPP improved STZ-induced diabetic nephropathy assessed by H&E staining, blood urea nitrogen content, and urine creatinine level. The molecular networking and Emperor analysis results indicated that CPF showed potential anti-hyperglycemic effects, and HPLC–MS/MS analysis indicated that CPF contains 3 phenolic acids and 9 flavonoids. In contrast, CPT (650 mg/kg) and CPC (300 mg/kg CPF + 180 mg/kg CPP + 650 mg/kg CPT) did not show anti-hyperglycemic effect. Taken together, polysaccharides and flavonoids are responsible for the anti-hyperglycemic effect of C. paliurus leaves, and the clinical application of C. paliurus need to be refined.     

First structural characterization of core modified 10,15-meso aryl azuliporphyrins: observation of C-H...pi interaction between pyrrole beta-CH and mesityl ring

First successful syntheses and structural characterization of new core modified meso aryl azuliporphyrins by a simple [3 + 1] methodology are reported.     

Uniform hierarchical silica film with perpendicular macroporous channels and accessible ordered mesopores for biomolecule separation

Herein, we demonstrate that silica films with perpendicular macroporous channels and accessible ordered mesopores can be conveniently prepared. The hierarchical macroporous–mesoporous silica films are synthesized by using zinc oxide nanorod array as macroporous template and CTAB surfactant as mesoporous template. In basic surfactant-containing solution, ordered mesoporous silica shells homogeneously grow on the zinc oxide nanorod array. The growth of the mesostructures do not require any chemical modification for the zinc oxide nanorod, which opens a new way for preparing hierarchical silica films with perpendicular mesochannels. The prepared hierarchical macroporous–mesoporous silica films possess a uniform thickness of 2 mm, large perpendicular macropores with a length of 1.8 mm and a width of 80 nm, and accessible ordered mesopores. Separation experiment demonstrates that this macroporous–mesoporous film can effectively separate biomolecules with different sizes.     

Orthogonal Halogen‐Bonding‐Driven 3D Supramolecular Assembly of Right‐Handed Synthetic Helical Peptides

Peptide‐mediated self‐assembly is a prevalent method for creating highly ordered supramolecular architectures. Herein, we report the first example of orthogonal C?X???X?C/C?X???π halogen bonding and hydrogen bonding driven crystalline architectures based on synthetic helical peptides bearing hybrids of l ‐sulfono‐γ‐AApeptides and natural amino acids. The combination of halogen bonding, intra‐/intermolecular hydrogen bonding, and intermolecular hydrophobic interactions enabled novel 3D supramolecular assembly. The orthogonal halogen bonding in the supramolecular architecture exerts a novel mechanism for the self‐assembly of synthetic peptide foldamers and gives new insights into molecular recognition, supramolecular design, and rational design of biomimetic structures.     

利用“网包法”制备高效液相色谱大环抗生素类手性固定相

万古霉素和替考拉宁都属于糖肽类的大环抗生素，具有立体的环状结构和多个手性中心，是两种常见的手性识别材料，广泛应用于对映体的色谱手性分离分析。该文以万古霉素和替考拉宁为手性选择剂，哌嗪为单体，4，4'-二苯基甲烷二异氰酸酯（MDI）、1，6-己二异氰酸酯（HDI）和2，4-甲苯二异氰酸酯（TDI）为交联剂，通过界面聚合反应形成网状层包裹硅胶载体的方法制得6种高效液相色谱手性固定相，用于分离外消旋化合物，并与MDI直接交联万古霉素和替考拉宁在硅胶表面所得固定相进行了比较。结果表明，利用"网包法"和直接交联法制备的手性柱与商品万古霉素和替考拉宁柱之间具有互补性，均对不同的外消旋体有不同程度的拆分。