Mussel‐inspired decoration of Ni(OH)2 nanosheets on 2D MoS2 towards enhancing thermal and flame retardancy properties of poly(lactic acid)

In the present work, a facile and environmental method was developed to fabricate the novel functionalized MoS₂ hybrid. Firstly, MoS₂ nanosheets were coated with polydopamine (PDA) through the self‐polymerization of dopamine (MoS₂‐PDA) in a buffer solution. Then the decoration of Ni(OH)₂ on the MoS₂‐PDA was synthesized because of the strong affinity of Ni²⁺ with hydroxyl groups in PDA. Finally, the as‐synthesized MoS₂‐PDA@Ni(OH)₂ was introduced into poly(lactic acid) (PLA) matrix to explore flame retardancy, thermal stability, and crystalline property of the composites. As confirmed by X‐ray diffraction (XRD), Fourier‐transform infrared spectrometer (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA), the MoS₂ nanosheets were dually modified with PDA and Ni(OH)₂ without destroying the original structures. The thermal degradation of PLA with MoS₂‐PDA@Ni(OH)₂ generated a notably higher yield of char. Moreover, the crystallization rate of composites is higher than neat PLA. The cone calorimeter test revealed that the introduction of 3% MoS₂‐PDA@Ni(OH)₂ resulted in lower Peak Heat Release Rate (PHRR) (decreased by 21.7%). Thus, the research provided an innovative functionalization method for manufacturing PLA composites with high performances.     

Direct synthesis and characterization of phenyl-functionalized SBA-15

Phenyl-functionalized SBA-15 materials (Ph-SBA-15) were directly synthesized by using tri-block copolymer Pluronic P123 as templating agent under acidic conditions. The samples were characterized by Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetry analysis (TGA) and N₂ adsorption-desorption. The results show that the phenyl groups are covalently attached to the pore wall of SBA-15 after modification. The functionalized materials still preserve a desirable two-dimensional P6mm hexagonal structure and have large specific surface area and pore volume although the molar ratio of phenyltrimethoxysilane in total silica precursors is as high as 23.0%.     

High effects of smoke suppression and char formation of Ni?Mo/Mg(OH)2 for polypropylene

The Ni? Mo/Mg(OH)₂ (NMM) hybrid as an efficient flame retardancy and smoke suppression composite for polypropylene (PP) was synthesized through Ni? Mo co‐precipitation on the surface of Mg(OH)₂ (MH) hexagonal nanosheets. Compared to PP/MH, PP/NMM exhibited excellent smoke suppressing and flame retardancy on the heat release rate, total heat release, smoke production rate, total smoke production, CO production rate and total CO production with the same loading. The reduced hazard of PP/NMM was mainly attributed to the high physical barrier effect of compact char residues on heat, smoke and combustible gas. The mechanism study indicated that multiwalled carbon nanotubes (MWCNTs) generated from the catalytic carbonization of PP by the Ni? Mo compound could play the role of “rebar” to strengthen the char residues, avoid the generation of cracks and form highly compact char layer. Furthermore, MgO could facilitate the production of MWCNTs through changing the pyrolysis process of PP and increasing the reaction time between pyrolysis gas and Ni? Mo compound. Hence, the new Ni? Mo/MH catalyst hybrid may explore the potential for solving the tough problem of the flammability and heavy smoke of the polyolefins system.     

A Zero‐Dimensional Organic Seesaw‐Shaped Tin Bromide with Highly Efficient Strongly Stokes‐Shifted Deep‐Red Emission

The synthesis and characterization is reported of (C₉NH₂₀)₂SnBr₄, a novel organic metal halide hybrid with a zero‐dimensional (0D) structure, in which individual seesaw‐shaped tin (II) bromide anions (SnBr₄^2?) are co‐crystallized with 1‐butyl‐1‐methylpyrrolidinium cations (C₉NH₂₀⁺). Upon photoexcitation, the bulk crystals exhibit a highly efficient broadband deep‐red emission peaked at 695 nm, with a large Stokes shift of 332 nm and a high quantum efficiency of around 46 %. The unique photophysical properties of this hybrid material are attributed to two major factors: 1) the 0D structure allowing the bulk crystals to exhibit the intrinsic properties of individual SnBr₄^2? species, and 2) the seesaw structure enabling a pronounced excited state structural deformation as confirmed by density functional theory (DFT) calculations.     

Silica‐based magnetic hybrid nanocomposite for the extraction and preconcentration of some organophosphorus pesticides before gas chromatography

The precise control of pesticide residues in foodstuffs depends significantly on the clean extraction of analytes using specifically designed separation methods. In this study, a one‐pot sol–gel process was used for the preparation of a magnetic hybrid silica gel tetraethylortho silicate‐cyanopropyltriethoxy silane nanocomposite. The prepared material was characterized using energy dispersive X‐ray spectroscopy, Fourier transform infrared spectroscopy, single‐point specific surface area, and scanning electron microcopy. The synthesized magnetic hybrid material was used as a solid phase extraction sorbent for the extraction and preconcentration of some organophosphorus pesticides before gas chromatography with a microelectron capture detector. The performance of the proposed magnetic solid‐phase extraction technique was validated by linearity (0.05–2 ng/mL), correlation coefficients (r² = 0.9993–0.9997), limit of detection (0.02–0.06 ng/mL, S/N = 3, n = 3), and intraday (RSD = 1.5–8.7%, n = 3) and interday precision (RSD = 5.5–9.3%, n = 12), while the recovery in real samples and equilibrium adsorption capacity was 72.02–103.84% and 8–20 mg/g, respectively. The magnetic solid‐phase extraction based on the hybrid nanocomposite revealed a high enrichment factor, an appropriate dynamic range, and great absorptive ability toward the selected organophosphorus pesticides spiked in real water samples.     

Porous Silica Obtained from Biodegradable and Biocompatible Inorganic-Organic Hybrid Materials

Porous silicas have been successfully prepared from poly(-caprolactone) (PCL)-silica hybrid materials based on the template approach. The final texture of the porous silica can be tailored by the PCL template, i.e., molecular weight and molecular weight distribution, content, type and number of reactive end-groups per chain. Porosity has been investigated by nitrogen adsorption-desorption technique and small angle X-ray scattering (SAXS).     

Syntheses and Characterizations of （CH3CH2CH2CH2NH3）6（BiI6）（I）2I3 and （NH3CH2CH2NH3）2Bi2I10

The title compounds have been respectively synthesized by solution process and solvothermal reaction, and their crystal structures were determined by X-ray diffraction method. For （CH3CH2CH2CH2NH3）6（BiI6）（I）2I3 1, it crystallizes in tficlinic, space group P1^- with Mr = 2049.76, a = 8.5719（1）, b = 11.7461（3）, c = 15.700（1）A, V = 1451.4（1）A^3, Z = 1, Dc = 2.345 g/cm^3, F（000） = 924, μ（MoKα） = 8.907 mm^-1, T = 293（2） K, the final R = 0.0655 and wR = 0.0804 for 2399 observed reflections with I 〉 2σ（I）. For （NH3CH2CH2NH3）2Bi2I10 2, it crystallizes in monoclinic, space group P21/n with Mr= 1811.20, a = 8.434（4）, b = 13.862（6）, c = 13.362（6）A, V = 1499.9（12）A^3, Z = 2, Dc = 4.010 g/cm^3, F（000） = 1536,μ（MoKα） = 22.007 mm^-1, T = 293（2） K, the final R = 0.0584 and wR = 0.1451 for 1798 observed reflections with I 〉 2σ（I）. The structures of 1 and 2 contain halobismuthate monomer and dimers, respectively. It is noteworthy that the dimers and their organic counters in 2 connect each other by N…I hydrogen bonds to form a layered structure, and the electrostatic interactions and crystal packing forces between layers give rise to the packing of the crystal. The optical absorption spectra of 1 and 2 reveal the appearance of sharp optical gaps of 2.13 and 2.01 eV, respectively.     

[（Mo2O6）（pyrazine）]的水热合成、晶体结构和热性能研究

用吡嗪-2,3-二羧酸、CoCl2·6H2O、MoO3和去离子水在413K下通过水热反应法得到了标题化合物[（Mo2O6）（pz）],该化合物晶体属于正交晶系,空间群为Pbca,晶胞参数为α=0．75778（15）nm,b=0．74057（15）nm,c=1．4112（3）nm,Z=4．单晶衍射数据表明标题化合物由二齿桥联配体吡嗪将二维网状[Mo2O6]。连接成具有三维网络结构的无机一有机杂化化合物,其中每个Mo原子以变型八面体构型和5个氧原子以及1个氮原子配位．标题化合物在300℃之前热性能稳定．     

Bacterial cellulose–silica organic–inorganic hybrids

Bacterial cellulose (BC) hydrated membranes present nanometric reticulated structure that can be used as a template in the preparation of new organic–inorganic hybrids. BC–silica hybrids were prepared from BC membranes and tetraethoxysilane, (TEOS) at neutral pH conditions at room temperature. Macroscopically homogeneous membranes were obtained containing up to 66 wt.% of silica spheres, 20–30 nm diameter. Scanning electron micrographs clearly show the silica spheres attached to cellulose microfibrils. By removing the cellulose, the silica spheres can be easily recovered. The new hybrids are stable up to 300 °C and display a broad emission band under UV excitation assigned to oxygen-related defects at the silica particles surface. Emission color can be tuned by changing the excitation wavelength.     

Site‐Selective Disulfide Modification of Proteins: Expanding Diversity beyond the Proteome

The synthetic transformation of polypeptides with molecular accuracy holds great promise for providing functional and structural diversity beyond the proteome. Consequently, the last decade has seen an exponential growth of site‐directed chemistry to install additional features into peptides and proteins even inside living cells. The disulfide rebridging strategy has emerged as a powerful tool for site‐selective modifications since most proteins contain disulfide bonds. In this Review, we present the chemical design, advantages and limitations of the disulfide rebridging reagents, while summarizing their relevance for synthetic customization of functional protein bioconjugates, as well as the resultant impact and advancement for biomedical applications.