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91.
Precisely Controlled Multidimensional Covalent Frameworks: Polymerization of Supramolecular Colloids
Dr. Yongguang Li Shanshan Wu Lingling Zhang Xin Xu Yajun Fang Juzhen Yi Dr. Jehan Kim Dr. Bowen Shen Prof. Myongsoo Lee Dr. Liping Huang Liwei Zhang Junhui Bao Prof. Hongbing Ji Prof. Zhegang Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(48):21709-21713
Rapid and selective removal of micropollutants from water is important for the reuse of water resources. Despite hollow frameworks with specific functionalized porous walls for the selective adsorption based on a series of interactions, tailoring a stable shape of nanometer- and micrometer-sized architectures for the removal of specific pollutants remains a challenge. Here, exactly controlled sheets, tubes, and spherical frameworks were presented from the crosslinking of supramolecular colloids in polar solvents. The frameworks strongly depended on the architecture of original supramolecular colloids. As the entropy of colloids increased, the initial laminar framework rolled up into hollow tubules, and then further curled into hollow spheres. These shape-persistent frameworks showed unprecedented selectivity as well as specific recognition for the shape of pollutants, thus contributing to efficient pollutant separation. 相似文献
92.
A new environment-friendly bentonite intercalation composite was successfully obtained from alumina sol intercalation. This process used industrial grade pseudo boehmite as the aluminum source and provided with the advantage of zero emission of acidic wastewater. The bentonite intercalation composite was investigated by XRF, ICP, XRD, FT-IR, BET, and pyridine-FTIR. Results indicated that the basal spacing was enlarged from 14.72 to 15.60 Å; the specific surface area increased by 128%; and the total acid content increased from 65.32 to 245.76 μmol/g. The catalytic activity of this composite was tested by alkylation of aromatics with olefins. The results show that the weak Lewis acid generated by extra-framework aluminum and specific surface area play a decisive role, while weak Brønsted acid site is not the active site for this alkylation reaction. 相似文献
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95.
Xin Dong Juan Yang Xiao-Ting Zheng Yan Chen Li-Hong Ye Bin Wang Hui Zheng Jun Cao Qiu-Yan Wang Yu-Han Hu 《Electrophoresis》2020,41(1-2):123-130
A novel micro matrix solid phase dispersion method was successfully used for the extraction of quaternary alkaloids in Phellodendri chinensis cortex. The elution of target compounds was accomplished with sodium hexanesulfonate as the eluent solvent. A neutral ion pair was formed between ion-pairing reagent and positively charged alkaloids in this process, which was beneficial for selectively extraction of polar alkaloids. Several parameters were optimized and the optimal conditions were listed as follows: silica gel as the sorbent, silica to sample mass ratio of 1:1, the grinding time of 1 min. The exhaustive elution of targets was achieved by 200 µL methanol/water (9:1) containing 150 mM sodium hexane sulfonate at pH 4.5. The method validation covered linearity, recovery, precision of intraday and interday, limits of detection, limits of quantitation, and repeatability. This established method was rapid, simple, environmentally friendly, and highly sensitive. 相似文献
96.
Chen Chao-Yue Qiao Yu Zhang Lei Wang Xin Yang Ting-Hai 《Research on Chemical Intermediates》2020,46(9):4079-4089
Research on Chemical Intermediates - When synthesizing cyclohexane-annulated pyrazolones from a cyclohexonedicarboxylate derivative with phenylhydrazine under the catalysis of sulfuric acid in the... 相似文献
97.
Peng Yang Xin Peng Ze-zhou Yang Prof. Ya-qin Chai Prof. Ruo Yuan Prof. Wen-bin Liang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(40):8767-8773
The evident contradiction between high local-concentration-based substrate reactivity and free-diffusion-based high reaction efficiency remains one of the important challenges in chemistry. Herein, we propose an efficient aggregation-induced synergism through the hydrophobic-driven self-assembly of amphiphilic oligonucleotides to generate high local concentration whereas retaining high reaction efficiency through hydrophobic-based aggregation, which is important for constructing efficient DNA nanomachines for ultrasensitive applications. MicroRNA-155, used as a model, triggered strand displacement amplification of the DNA monomers on the periphery of the 3D DNA nanomachine and generated an amplified fluorescent response for its sensitive assay. The local concentration of substrates was increased by a factor of at least 9.0×105 through hydrophobic-interaction-based self-assembly in comparison with the traditional homogeneous reaction system, achieving high local-concentration-based reactivity and free-diffusion-based enhanced reaction efficiency. As expected, the aggregation-induced synergism by hydrophobic-driven self-assembly of amphiphilic oligonucleotides created excellent properties to generate a 3D DNA nanomachine with potential as an assay for microRNA-155 in cells. Most importantly, this approach can be easily expanded for the bioassay of various biomarkers, such as nucleotides, proteins, and cells, offering a new avenue for simple and efficient applications in bioanalysis and clinical diagnosis. 相似文献
98.
Dr. Qiao Chen Xin Yi Meirong Huang Wenjia Wu Qiyang Song Changjiang Nie Prof. Shun Wang Prof. Hongwei Zhu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(33):7463-7469
Precursors and catalysts play vital roles in chemical reactions. Considerable efforts have been devoted to the investigation of catalysts for graphene growth by chemical vapor deposition in recent years. However, there has been little research on precursors because of a lack of innovation in term of creating a controllable feeding method. Herein, we present a novel sustained and controlled release approach, and develop a convenient, safe, and potentially scalable feeding system with the assistance of matrix materials and a simple portable feeder. As a result, a highly volatile liquid precursor can be fed accurately to grow large-area, uniform graphene films with optimal properties. This feeding approach will further benefit the synthesis of other two-dimensional materials from various precursors. 相似文献
99.
Dr. Jinwen Qin Linlin Hao Xin Wang Yan Jiang Dr. Xi Xie Prof. Rui Yang Prof. Minhua Cao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(49):11231-11240
The optimization of three-dimensional (3D) MXene-based electrodes with desired electrochemical performances is highly demanded. Here, a precursor-guided strategy is reported for fabricating the 3D SnS/MXene architecture with tiny SnS nanocrystals (≈5 nm in size) covalently decorated on the wrinkled Ti3C2Tx nanosheets through Ti−S bonds (denoted as SnS/Ti3C2Tx-O). The formation of Ti−S bonds between SnS and Ti3C2Tx was confirmed by extended X-ray absorption fine structure (EXAFS). Rather than bulky SnS plates decorated on Ti3C2Tx (SnS/Ti3C2Tx-H) by one-step hydrothermal sulfidation followed by post annealing, this SnS/Ti3C2Tx-O presents size-dependent structural and dynamic properties. The as-formed 3D hierarchical structure can provide short ion-diffusion pathways and electron transport distances because of the more accessible surface sites. In addition, benefiting from the tiny SnS nanocrystals that can effectively improve Na+ diffusion and suppress structural variation upon charge/discharge processes, the as-obtained SnS/Ti3C2Tx-O can generate pseudocapacitance-dominated storage behavior enabled by engineered surface reactions. As predicted, this electrode exhibits an enhanced Na storage capacity of 565 mAh g−1 at 0.1 A g−1 after 75 cycles, outperforming SnS/Ti3C2Tx-H (336 mAh g−1), SnS (212 mAh g−1), and Ti3C2Tx (104 mAh g−1) electrodes. 相似文献
100.
Metal-Free,Visible-Light-Induced Selective C−C Bond Cleavage of Cycloalkanones with Molecular Oxygen
Hong Xin Prof. Dr. Xin-Hua Duan Dr. Le Liu Prof. Dr. Li-Na Guo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(51):11690-11694
A metal-free, visible-light-induced oxidative C−C bond cleavage of cycloketones with molecular oxygen is described. Cooperative Brønsted-acid catalysis and photocatalysis enabled selective C−C bond cleavage of cycloketones to generate an array of γ-, δ- and ϵ-keto esters under very mild conditions. Mechanistic studies indicate that singlet molecular oxygen (1O2) is responsible for this transformation. 相似文献