ChemSusChem
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2015
·Vol. 8
·期 12
·2066-2072
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IF 7.657
Yehong Wang,Jian Zhang,Jing Liu,Chaofeng Zhang,Zhixin Zhang,Jie Xu,Shutao Xu,Fangjun Wang,Feng Wang
Graphical CO 2 -mediated reactions: CO 2 -mediated metathesis reactions between amines and DMF to synthesize formamides are described. The N -formylation of amines to formamides is achieved by activating amines, not DMF, via a C N and N H bond metathesis reaction. Using this method, primary, secondary, aromatic, and heterocyclic amines as well as diamines can be obtained with good to excellent formamide yields. Herein, we report CO 2 -mediated metathesis reactions between amines and DMF to synthesize formamides. More than 20 amines, including primary, secondary, aromatic, and heterocyclic amines, diamines, and amino acids, are converted to the corresponding formamides with good-to-excellent conversions and selectivities under mild conditions. This strategy employs CO 2 as a mediator to activate the amine under metal-free conditions. The experimental data and in situ NMR and attenuated total reflectance IR spectroscopy measurements support the formation of the N -carbamic acid as an intermediate through the weak acid–base interaction between CO 2 and the amine. The metathesis reaction is driven by the formation of a stable carbamate, and a reaction mechanism is proposed.
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JOURNAL OF ORGANIC CHEMISTRY
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2019
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IF 4.745
Na Li,Jinku Bai,Xiaolin Zheng,Honghua Rao
An iron-catalyzed methylene forming strategy is disclosed through sequential C–H and C–O bond functionalization of methanol with cosolvent water. This protocol provides an easy and novel access to methylene-tethered imidazo[1,2-a]pyridine and 2-aminopyridine analogues in a sustainable manner and represents a complementary approach to traditional methylene forming strategies.
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Frontiers in Chemistry
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2020
·
IF 3.693
Wang Xiaodong,Hu Weizhao,Hu Yuan
In this study, h-BN@PDA@TiO2 hybrid nanoparticles were prepared and used as functional fillers to prepare PVA nanocomposites, and the effects of hybrid particles on PVA thermal conductivity and flame retardant properties were studied. The results showed that hybrid particles could significantly improve the thermal conductivity and flame retardant performance of PVA composites, and effectively inhibit the release of toxic gases such as combustible pyrolysis products and CO, which enhanced the fire safety of PVA composites. When the addition amount of hybrid particles is 5 wt%, the thermal conductivity of PVA composites is 239.1% higher than that of the pure PVA and the corresponding temperature of PVA composites with a mass loss of 5 wt% was 16.2°C higher than that of the pure PVA. This is due to the barrier effect of h-BN and the protective effect of dense carbon layer catalyzed by TiO2.
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CEMENT AND CONCRETE RESEARCH
·
2025
·
IF 13.1
Xin Liu,Dining Li,Hui Xie,Jiachen Yao,Xuyan Shen,Haochuan Wang,Zhengyao Qu,Zuhua Zhang,Pan Feng
Alkali-free aluminum sulfate (AS)-based accelerators have become a widely adopted and indispensable admixture for shotcrete applications. However, their effects on the formation kinetics and properties of calcium silicate hydrate (C-S-H) – the primary hydrate in shotcrete – remain insufficiently understood. To bridge this knowledge gap, a combination of isothermal calorimetry, QXRD, and TGA was employed to uncover the temporal evolution of C-S-H. In addition, the chemical compositions and silicate chain structure were comprehensively examined using BSE-EDS, 27 Al NMR, coupled with 29 Si NMR techniques. Our results demonstrate that AS addition accelerated C 3 S hydration, promoting the C-S-H nucleation and growth rate. This acceleration effect can be ascribed to (1) the accelerated dissolution of silicate phases at early stages, and (2) the formation of divergent C-S-H needles, providing more nucleation sites while mitigating impingement between adjacent C-(A)-S-H needles. Multiple characterizations confirmed the enhanced incorporation of aluminum into C-S-H, predominately at the bridging site. Notably, increasing AS content decreased the Si/Ca of the C-(A)-S-H and concurrently enhanced the aluminum incorporation. This compositional shift led to the formation of longer aluminosilicate chains and concomitant improvements in the hardness and elastic modulus of C-(A)-S-H. These findings offer valuable insights into AS-induced alterations in C-(A)-S-H within accelerated cement pastes, facilitating the deeper understanding of the role of C-(A)-S-H in strength development and long-term durability of shotcrete.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2025
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IF 9
Xinru Wang,Yannan Zhou,Jiaoyu Peng,Wenhu Li,Xin Liu
Octadecylamine hydrochloride (ODA H) as an efficient flotation collector is extensively employed in KCl manufacturing. However, the residual of ODA-H not only directly influences KCl application fields, but also poses environmental risks owing to its low biodegradability. Meanwhile, the removal cost is comparatively high because of KCl solubility. In this study, a simple yet effective strategy was proposed to achieve efficient in-situ desorption of ODA-H from the solid KCl surface. The desorption behavior and underlying mechanism were systematically investigated, focusing on charge state conversion, interfacial wettability change, and ODA-H aggregation. The results demonstrated that OH − significantly enhanced the removal efficiency of ODA H, with a removal rate of 86 % achieved when the pH of the saturated KCl solution was raised to 14. In-situ Raman spectroscopy and Molecular Dynamics simulation elucidated the mechanism of OH − , which could accelerate ODA-H desorption kinetics by disrupting the electrostatic interaction between ODA-H and KCl surface, thereby altering its aggregation behavior. Furthermore, the disruption mechanism of interfacial hydrogen-bonding networks during the OH − -promoted desorption process was confirmed. The synergistic effects resulting from these enhancements facilitated the highly efficient desorption of ODA-H from the solid KCl surface. Importantly, industrial-grade KCl was refined with the ODA-H desorption efficiency of 73.95 %. This study will provide a new idea and mechanism explanation for the removal of pollutants on the soluble solid surface in high-salt solution.
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TETRAHEDRON
·
2018
·
IF 2.377
Jie Zhu,Wenhui Zhu,Ping Xie,Charles U. Pittman,Aihua Zhou
A novel and efficient Ni-catalyzed aryl- and alkyl-selenation of imidazo[1,2-α]pyridines employing selenium powder has been developed for the first time. The significant advantages of this protocol are that it is an inexpensive nickel catalyst and exhibits broad functional-group compatibility and good reaction yields.
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INDUSTRIAL CROPS AND PRODUCTS
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2025
·
IF 6.2
Qi Zhang,Minghui Li,Zhuofan Zuo,Tianhang Zhan,Xiaoyan Li,Wei Zhang
Cotton, as one of the world’s most crucial economic crops, suffers from a markedly shortened service life of its fabrics due to microbial degradation. In this study, N-isopropylacrylamide (NIPAM) containing amide bonds was grafted onto cotton fibers via atom transfer radical polymerization (ATRP) to develop a heat-resistant and wash-durable N-halamine functionalized cotton fabric (PN@CF-Cl). The resulting material exhibited rapid and potent antibacterial activity, killing over 85 % of bacteria within 1 min of contact and achieving > 99.9 % inactivation of Staphylococcus aureus and Escherichia coli within 10 min. After 50 washing cycles at 75 °C, the antibacterial activity retention remained above 97 %. Following storage for 30 days, rechlorination restored the active chlorine content to its initial level. Even after 10 consecutive chlorination–reduction cycles, the active chlorine recovery reached 98.9 %. In addition, the fabric demonstrated high hydrophobicity, air permeability, and moisture vapor transmission. Molecular dynamics (MD) simulations further validated the dynamic interconversion between N–Cl and N–H in the material, elucidating the underlying mechanism for its regenerative performance. Functionalized cotton fabrics based on the N–Cl/N–H dynamic cycling mechanism can extend product lifespan and hold significant promise for applications in medical protective equipment and smart home textiles.
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Molecular Catalysis
·
2024
·
IF 3.9
XiaoNing Gao,YanXiao Zhang,Wei Fu,Hong Zhou,Lu Feng
Conventional hydrolysis of total saponins for the extraction of diosgenin, an essential ingredient in the production of steroid hormones, has caused significant ecological pollution, making efficient and clean extraction methods necessary. Here, UiO-66-NH 2 with defect sites containing Zr-coordinated hydroxide and water groups was synthesized using concentrated HCl as a crystal modulator, which was further treated with trimethylsilyl trifluoromethanesulfonate (Me 3 SiOTf) to afford UiO-66-NH 2 OTf using the oxygen affinity of the Me 3 Si group. The strong Lewis acid UiO-66-NH 2 OTf was used to extract diosgenin from the total saponin, and the extraction temperature, extraction time and amount of addition were optimized using single-factor experiments and the response surface method. In addition, high-resolution mass spectrometry has been used to analyze the resulting compounds, thus suggesting an alcoholysis pathway and an alcoholysis mechanism for the total saponins.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2024
·
IF 4.9
Hongxin Yan,Guoqing Xiao,Chunlin Chen,Mingtan Wang,Rui Zou,Yinke Lan,Jing Gou,Junjie Cao,Xiyi Ma
Hexagonal boron nitride (h-BN) has excellent lamellar structure and electrical insulation properties, and excels in improving the corrosion resistance of coatings. By utilizing the abundant hydroxyl and amino functional groups on the polydopamine surface, h-BN is endowed with excellent hydrophilicity. Simultaneously, the polysaccharide polymer MD-GT-CS (MGC), formed by cross-linking maltodextrin (MD), gelatin (GT), and chitosan (CS), was combined with the active sites on the surface of BN@PDA, which conferred pH-responsive functionality to the BN@PDA@MGC hybrid material. In addition, cerium ions were introduced into the carboxyl and amino sites on the MGC surface, resulting in the synthesis of BN@PDA@MGC(Ce) (BPMGC), a hybrid material that combines the layered barrier properties, pH responsiveness, and self-repairing functions. The BPMGC/EP composite coating was prepared by doping the hybrid material with EP. The EIS test results showed that the |Z| 0.01 Hz value of the composite coating reached 1.45 × 10 9 Ω cm 2 after 40 d, which is an improvement of four orders of magnitude compared to EP (6.85 × 10 5 Ω cm 2 ). The results of EIS tests at different pH conditions showed that after 40 d of immersion at pH = 3 and 5, the |Z| 0.01 Hz value decreased by two orders of magnitude, but was still two orders of magnitude higher than that of EP at pH = 7. Meanwhile, the strong self-healing ability of BPMGC/EP was determined by EIS analysis of the scratched coating, salt spray test, SEM and EDS analysis of the corroded area. The experimental results show that the incorporation of BPMGC provides a new method to improve the barrier and self-healing properties of epoxy resins.
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Advanced Membranes
·
2025
·
IF 9.5
Yixin Wang,Yingda Huang,Kang Geng,Bin Hu,Ruofei Gao,Erqiang Yang,Junfen Li,Jiandang Xue,Nanwen Li
Anion exchange membrane (AEM) is a core component of potentially more efficient and cost-effective anion exchange membrane water electrolyzers (AEMWEs), which combine the advantages of traditional alkaline water electrolyzers (AWEs) and proton exchange membrane water electrolyzers (PEMWEs). Despite extensive research efforts in recent years, AEMs still face significant challenges, particularly insufficient alkaline stability and limited dimensional/mechanical stability. In this work, we enhanced the mechanical and alkaline stability of AEMs by incorporating the thermoplastic elastomer polystyrene-block-polybutadiene-block-polystyrene (SBS) into the poly (terphenyl piperidinium) (PTP) matrix. The optimal PTP-SBS-2.5% membrane exhibits outstanding dimensional stability (9.4% swelling at 20 °C), robust mechanical properties (tensile strength of 51.5 MPa and elongation of 63.1% at break in wet state), low alkali absorption (0.875%) and exceptional alkaline stability (92.4% conductivity retention after 1500 h). Notably, the membrane demonstrates stable operation in AEMWE for over 3000 h with a low voltage decay rate of 41.1 μV h –1 . These results highlight the significance of SBS in enhancing both the alkaline stability and mechanical performance of PTP-based AEMs.
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ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Yu Bai,Haiping Zhou,Jia-Lin Yang,Qingqing Pan,Jiawei Wang,Yunpeng Wu,Xing-Long Wu
Aqueous zinc-ion batteries (AZIBs) have great potential for large-scale energy storage applications. However, the parasitic reactions, such as continuous hydrogen evolution reaction (HER), seriously hamper the reversibility and cycling stability of the zinc metal anode (ZMA), limiting its practical application. In this paper, a pre-growth interfacial layer strategy is adopted to grow the enol/ketone conversion interfacial layer on the surface of ZMA (denoted as Zn@AA). H + can be reversible “lock/unlock” during reversible enol/ketone conversion reaction. It not only broadens the capacity of AZIBs (Zn 2+ /H + co-insertion), but also inhibits the HER reaction (the amounts of H 2 evolution decreased obviously in both Zn@AA||Zn@AA and Zn@AA||VO 2 ·H 2 O@Ppy (Ppy denote as polypyrrole) cells by on-line differential electrochemical mass spectrometry analysis), thereby improving its stability performance. The cycle life of the assembled Zn@AA||Zn@AA cell exceeded 3200 h at 1 mA cm −2 and 1 mA h cm −2 . Furtherly, the Zn@AA||VO 2 ·H 2 O@Ppy full cell also exhibited excellent cycling stability and capacity retention. This work provides new ideas for modifying the ZMA interfacial layer to inhibit the HER, which guides the development of AZIBs.
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EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
·
2015
·Vol. 2016
·期 2
·325-330
·
IF 3.065
Wannian Zhao,Lei Xu,Yingcai Ding,Ben Niu,Ping Xie,Zhaogang Bian,Denghong Zhang,Aihua Zhou
Coumarin derivatives are highly valuable compounds in drug discovery. Herein, we have developed two new coupling reactions that involve coumarins and either aldehydes or di- tert -butyl peroxide (DTBP) in the presence of inexpensive copper or iron catalysts. Both of these reactions proceed through a C(sp 2 )–H functionalization process to regioselectivity generate keto- or methyl-substituted coumarin derivatives in moderate to good yields These coupling reactions will enrich current coumarin chemistry. Graphical Two coupling reactions that regioselectively yield either keto- or methyl-substituted coumarin derivatives by proceeding through a C(sp 2 )–H functionalization process were successfully developed. The coupling of coumarins with either aldehydes or di- tert -butyl peroxide (DTBP) generated the corresponding products in moderate to good yields.
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