HIGH PERFORMANCE POLYMERS
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2015
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IF 1.286
Yewei Xu,Yi Sun,Yonglin Lei,Jichuan Huo,Lin Zhang
This article presents a convenient polymerization route to synthesize poly(arylene ether)s containing N-arylenebenzimidazolyl groups. The novel polymers were prepared by a catalyst-free nucleophilic substitution reaction, in which the N–H and O–H sites were removed from 2-(2-hydroxyphenyl)-1H-benzimidazole with different activated difluorides containing carbonyl groups in sulfolane. The reaction was carried out in the presence of anhydrous potassium carbonate at 210°C. The structures of the polymers were characterized using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and elemental analysis. The results show good agreement with the proposed structure. All resulting polymers show essentially amorphous patterns. Moreover, differential scanning calorimetry and thermogravimetric measurements show that the polymers have high glass transition temperatures (>209°C), good thermostability, and high decomposition temperatures (>425°C). Furthermore, the polymers also exhibit excellent solubility in common organic solvents.
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BIOORGANIC & MEDICINAL CHEMISTRY
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2013
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IF 2.903
Xiu Liu,Ling Zhang,Jin-Guo Tan,Han-Hong Xu
Based on the discovery of thymine as an ecdysteroid agonist, a series of 1,4-disubstituted diacylhydrazine derivatives with a thymine moiety were designed and synthesized. The activities of these compounds against Spodoptera litura (Fabricius) were evaluated by the insect immersion method. Results showed that compound 2h with an N -cyclohexylmethyl substituent exhibits the most potent agonist activity with a median lethal concentration of 23.21 μg/mL. This compound also caused malformation of molting larvae and adults. Compound 2h was further demonstrated as an ecdysteroid agonist by reporter gene assay on the Spodoptera frugiperda cell line (Sf9 cells). A molecular docking study indicated that hydrophobic interactions and the formation of hydrogen bonds between the compounds and the ecdysone receptor play critical roles in promoting the binding affinity of the compound. The structure of compound 2h may serve as a favorable template for the development of new ecdysteroid agonists with a pyrimidinedione moiety.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2017
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IF 2.323
Dong-Fang Zhao,Li-Sheng Wang,Jian Sun,Chuan-Ming Chen
A phosphorus flame retardant named N,N′-piperazinebis(neopentylglycol)phosphoramidate (PBNGP) was synthesized and characterized by elemental analysis, Fourier transform infrared spectroscopy, mass spectra, and nuclear magnetic resonance. Its thermal properties were evaluated via thermogravimetric analysis and differential scanning calorimetry. The solubilities of PBNGP in selected solvents at T = (293.15 to 333.15) K and atmospheric pressure were measured via a static-analytic method. The experimental data were correlated with Scatchard–Hildebrand, Buchowski-Ksiazczak, Wilson, nonrandom two liquid, and universal quasichemical equations. The calculated results showed that all of these models can reproduce the experimental data well, and the Wilson model gives the best correlation, with an overall relative standard deviation of 0.70%. The solubility parameter of PBNGP was calculated using the Scatchard–Hildebrand methodology.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Hao Jiang,Mei Yan,Hao Chen,Xue Chen,Yutuo Fu,Chongshen Guo
How to make full use of solar energy and improve the efficiency of charges separation of photocatalysis has been a concern for scientists all along. To achieve this, this work designed an n-n + homojunction of S-doped SnFe 2 O 4 and applied it to near infrared driven photocatalytic degradation and sterilization. The experimental results demonstrated that S doping significantly enhanced the photocatalytic performance of SnFe 2 O 4 . The degradation rate of ciprofloxacin and the removal rate of Staphylococcus aureus ( S. aureus ) reached up to approximately 65 % and 100 % after 6 h irradiation, respectively. The S-doping could increase the content of shallow trap states in SnFe 2 O 4 , effectively inhibiting the recombination of photogenerated electrons and holes. Moreover, S-doping also enhances the n-type character and forms n-n + homojunction. This n-n + homojunction generates a built-in electric field within the sample, which causes band bending and promotes photogenerated charges transfer and separation. Consequently, more carries are available for the generation of reactive oxygen species. Free radical quenching experiments and ESR tests show that •O 2 − is the main free radical in the photocatalysis. In addition, DFT calculations confirmed the enhanced activation of O 2 after S doping. This work provides a feasible way to effectively promote charges separation and transfer in metalloid-based photocatalysts.
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ELECTROCHIMICA ACTA
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2011
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IF 3.65
Yan Liang,Hongyun Liu,Kaina Zhang,Naifei Hu
N,N-diethylacrylamide (DEA) and 4-vinylpyridine (4VP) were polymerized into P(DEA-co-4VP) copolymer hydrogel films with immobilized glucose oxidase (GOD) on electrode surface with the simple one-step procedure under mild conditions, designed as P(DEA-co-4VP)-GOD. Cyclic voltammetric (CV) response of ferrocenedicarboxylic acid (Fc(COOH) 2 ) probe at P(DEA-co-4VP)-GOD film electrodes was very sensitive to environmental pH, temperature, and sulfate concentration. For example, in pH 5.0 buffers, the CV response of Fc(COOH) 2 was quasi-reversible with quite large peak heights at 25 °C for the films, showing the on state; while at pH 9.0, the peaks were greatly suppressed and the system was at the off state. This pH-sensitive on-off switching behavior of the films toward the probe was reversible and could be repeated for many times between pH 5.0 and 9.0. Similarly, the film system could be switched on-off reversibly when the temperature was changed between 25 and 39 °C, or when the concentration of Na 2 SO 4 was changed between 0 and 0.50 M. This triply responsive property could be further used to realize triply switchable electrochemical oxidation of glucose catalyzed by GOD immobilized in the films and mediated by Fc(COOH) 2 in solution. The responsive mechanism of the system was also explored and discussed. The pH-sensitive property was attributed to the electrostatic interaction between the P4VP component of the films and the probe at different pH, while the thermo- and sulfate-sensitive behavior was ascribed to the structure change of PDEA constituent of the films with temperature and Na 2 SO 4 concentration, respectively. These “smart” films combine the unique stimuli-responsive properties of both P4VP and PDEA with enzymatic reactions and may be used to fabricate a novel type of multi-controllable electrochemical biosensors based on bioelectrocatalysis.
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Soft Matter
·
2024
·Vol. 20
·期 37
·7448-7456
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IF 2.9
Cuihong Ma,Cong Du,Qing Bo Tong,Xin Ning Zhang,Miao Du,Qiang Zheng,Zi Liang Wu
Incorporating associative interactions as the energy dissipation units has been recognized as an effective strategy to develop tough hydrogels. For hydrogen-bond associations, however, it is highly challenging to stabilize them under aqueous conditions. Although affording cooperativity can enhance and stabilize the hydrogen bonds, it usually requires stepwise polymerization to form these cooperative associations between different polymers and networks. Here, we report a series of tough supramolecular hydrogels with robust hydrogen-bond associations between grafted polymers that are synthesized by polymerization of a macromonomer of poly(N,N-dimethylacrylamide) (PDMAA) and a small monomer of methacrylic acid. The grafted chains of PDMAA form cooperative hydrogen bonds with the main chain of poly(methacrylic acid) (PMAAc), forming supramolecular hydrogels with high toughness and good stability. The tough and stiff hydrogels are in a glassy state, exhibit forced elastic deformation at room temperature, and remain stable over a wide pH range. In contrast, hydrogels prepared by the copolymerization of DMAA and MAAc are swollen and weak in water due to the lack of successive hydrogen donor/acceptor units and the absence of cooperative hydrogen bonds. In addition, these tough hydrogels exhibit good recyclability and shape memory properties, owing to the supramolecular nature of the network and the temperature-dependent mechanical properties. The influence of polymer structure on the associative interactions and macroscopic properties of the hydrogels should be informative for the design of tough soft materials with versatile applications.
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Journal of Energy Chemistry
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2024
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IF 14
Yutong Jing,Qiang Lv,Yujia Chen,Bo Wang,Bochen Wu,Cheng Li,Shengbo Yang,Zhipeng He,Dianlong Wang,Huakun Liu,Shixue Dou
Polymer solid electrolytes (SPEs) based on the [solvate-Li + ] complex structure have promising prospects in lithium metal batteries (LMBs) due to their unique ion transport mechanism. However, the solvation structure may compromise the mechanical performance and safety, hindering practical application of SPEs. In this work, a composite solid electrolyte (CSE) is designed through the organic-inorganic synergistic interaction among N , N -dimethylformamide (DMF), polycarbonate (PC), and Mg 2 B 2 O 5 in poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). Flame-retardant Mg 2 B 2 O 5 nanowires provide non-flammability to the prepared CSEs, and the addition of PC improves the dispersion of Mg 2 B 2 O 5 nanowires. Simultaneously, the organic-inorganic synergistic action of PC plasticizer and Mg 2 B 2 O 5 nanowires promotes the dissociation degree of LiTFSI and reduces the crystallinity of PVDF-HFP, enabling rapid Li ion transport. Additionally, Raman spectroscopy and DFT calculations confirm the coordination between Mg atoms in Mg 2 B 2 O 5 and N atoms in DMF, which exhibits Lewis base-like behavior attacking adjacent C–F and C–H bonds in PVDF-HFP while inducing dehydrofluorination of PVDF-HFP. Based on the synergistic coupling of Mg 2 B 2 O 5 , PC, and DMF in the PVDF-HFP matrix, the prepared CSE exhibits superior ion conductivity (9.78×10 −4 S cm −1 ). The assembled Li symmetric cells cycle stably for 3900 h at a current density of 0.1 mA cm −2 without short circuit. The LFP||Li cells assembled with PDL-Mg 2 B 2 O 5 /PC CSEs show excellent rate capability and cycling performance, with a capacity retention of 83.3% after 1000 cycles at 0.5 C. This work provides a novel approach for the practical application of organic-inorganic synergistic CSEs in LMBs.
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JOURNAL OF MOLECULAR STRUCTURE
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2024
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IF 4
Tianyang Hou,Yuangang Xu,Ze Xu,Xiaopeng Zhang,Ming Lu
The formation of non-metallic pentazolate salts from the combination of simple nitrogen-rich cations with cyclo -N 5 − is expected to be applied in propellants and explosives. In this work, a series of structurally similar cations ([NH 3 CH 3 ] + , [NH 2 (CH 3 ) 2 ] + , [NH(CH 3 ) 3 ] + , and [N(CH 3 ) 4 ] + ) were used to synthesize four cyclo -N 5 − containing energetic salts, and the contribution of crystal stacking mode, hydrogen bonding, C–H··· π and π -stacking interactions in the stabilization of cyclo -N 5 − salts has been investigated by geometrical and Hirshfeld surface analyses as well as theoretical calculations. All salts have been thoroughly characterized by single-crystal X-ray diffraction, infrared (IR), multinuclear NMR ( 1 H and 13 C) spectroscopy, and elemental analysis. The decomposition temperatures of all salts are higher than 75 °C, as measured by thermogravimetric (TG). These compounds all show low sensitivities (IS ≥ 35 J, FS > 360 N) measured by standard BAM methods. Their heats of formation and detonation performances were calculated using the Born–Haber energy cycle and K-J method (“Pilem” program), respectively. This study has great significance for future design and synthesis of cyclo -N 5 − containing energetic materials.
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ACS Applied Materials & Interfaces
·
2025
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IF 8.2
Long Li,Yan Wu
This study reports a strategy for constructing highly efficient single-atom photocatalysts through the formation of Ni–N chemical bonds. By anchoring Ni single atoms on nitrogen-doped ZnIn2S4 (N-ZIS), we created a localized charge region that enables directed interfacial charge transfer. The newly formed Ni–N bond plays dual roles of significantly enhancing charge carrier separation and prolonging their lifetime, and serving as an efficient electron transfer pathway from N trap states to Ni active sites. Combined experimental characterization and density functional theory (DFT) calculations confirm the unique stabilizing effect of single Ni atoms in the N-ZIS matrix and elucidate the charge transfer mechanism through Ni–N bridges. The optimized 5%Ni–N30-ZIS photocatalyst exhibits exceptional hydrogen evolution performance, surpassing most previously reported ZIS-based systems. This work highlights the crucial importance of precise control over interfacial chemical bonding at the molecular level for achieving efficient spatial charge separation in inorganic photocatalysts, providing insights for the design of high-performance photocatalytic materials.
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Polymers
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2024
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IF 4.7
Jinyu Zhang,Dezhi Qu,Shuyu Wang,Shien Qi,Huajiang Zuo
In this study, polyacrylic acid hydrogels were prepared by modulating the cross-linking agent mass ratio using UV and heat curing methods. The structures and properties of the hydrogels were characterized and analyzed using Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The results showed that the mechanical properties of the hydrogels prepared through UV curing were better than those prepared through heat curing. The maximum mechanical tensile strength of 139 kPa was achieved at a cross-linking agent mass ratio of 3.85% with 20 min of UV curing, and the maximum mechanical compressive strength of 0.16 MPa was achieved at a cross-linking agent mass ratio of 2.91% with 20 min of UV curing. However, the hydrogels prepared by heat curing had a higher tensile strength than those prepared using the heat curing method. In addition, the thermally cured hydrogels had higher water absorption and adsorption properties. Moreover, the PAA hydrogels prepared at cross-linking agent mass ratios of 1.91 and 2.91% with 2 h of the heat curing method had the best swelling properties. Moreover, the increase in the cross-linker mass concentration led to a decrease in the pore size and porosity and to a more compact structure.
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Catalysts
·
2025
·Vol. 15
·期 9
·850
·
IF 4
Qiongqiong He,Xuewen Wu,Ping Ma,Zhaoyang Song,Xiaoqi Wu,Ruize Gao,Zhenyong Miao
Phenol is a refractory organic pollutant that is difficult to degrade in wastewater treatment, and efficiently and stably degrading phenol presents a significant challenge. In this study, iron-doped humic acid-based nitrogen–carbon materials were prepared to activate peroxymonosulfate (PMS) for the degradation of phenol. The Fe-N-C/PMS system achieved a phenol degradation rate of 99.71%, which follows a first-order kinetic model, with the reaction rate constant of 0.1419 min−1. The phenol degradation rate remained above 92% in inorganic anions (Cl−, SO42−, HCO3−) and humic acid and the system maintained a 100% phenol removal rate over a wide pH range (3–9). The iron in the catalyst predominantly exists in the forms of Fe0and Fe3C, and Fe0, Fe2+/Fe3+are the main active sites that promote PMS activation during the reaction. Additionally, Fe-N-C has a large specific surface area (1041.36 m2/g). Quenching experiments and electron spin resonance (ESR) spectroscopy detected the active free radicals in the Fe-N-C/PMS system: SO4•−, •OH, O2•−, and1O2. The mechanism for phenol degradation was discussed, involving radical pathways (SO4•−, •OH, O2•−) and the non-radical pathway (1O2), in the Fe-N-C/PMS system activated by Fe0, Fe2+/Fe3+, sp2hybridized carbon, C-O/C-N, C=O, and graphitic nitrogen active sites. This study provides new insights into the synthesis of efficient carbon-based catalysts for phenol degradation and water remediation.
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JOURNAL OF CHEMICAL THERMODYNAMICS
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2025
·
IF 2.2
Lijiao Ma,Yudong Ding,Yi Zhang,Xun Zhu,Hong Wang,Min Cheng,Qiang Liao
To reduce CO 2 emissions and address issues with conventional amine-based aqueous absorbents, a mixed nonaqueous solution of monoethanolamine (MEA) and N , N -dimethylformamide (DMF) was proposed. The density, dynamic viscosity and refractive index of fresh MEA-DMF solutions (10-50 wt% MEA) and CO 2 -loaded solutions (0.10–0.51 mol CO 2 ·(mol MEA) −1 ) were measured across the temperature range of 298.15–333.15 K. The values for fresh solutions were correlated with concentration and temperature using the Jouyban-Acree model (JAM) and an exponential equation. Then the results after CO 2 absorption were derived from the CO 2 loading amount. Additionally, CO 2 absorption performance of MEA-DMF with various concentrations at 303.15–333.15 K and 9.64–134.52 kPa was assessed to determine gas-liquid equilibrium and develop semi-empirical correlations. Nuclear magnetic resonance (NMR) analysis confirmed that carbamate was the primary product formed after CO 2 absorption in the nonaqueous absorbent. These studies provide essential data for equipment design and absorbent optimization. MEA-DMF solutions demonstrate favorable viscosity and CO 2 absorption performance, supporting the potential use of nonaqueous absorbents in industrial CO 2 capture technologies.
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