INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2014
·
IF 2.93
Junxian Wang,Jie Huang,Haolong Xie,Ailan Qu
A photocatalyst composed of graphite-like carbon nitride (g-C 3 N 4 ) and TiO 2 was fabricated by a simple method to calcine the mixture of melamine and TiO 2 precursor. The photocatalyst has enhanced photoactivity for hydrogen evolution from water. Characterization by XRD , FTIR, SEM and elemental analysis showed that the crystal structure and morphologies of composites were affected by the amount of melamine in the composite. The UV–Vis characterization displayed that the optical absorption range of g-C 3 N 4 /TiO 2 hybrid was broadened with a synergistic effect . The photoactivity for H 2 evolution was shown that the best result obtained from the composite with 67 wt% melamine has about 5 times improvement compared with bare TiO 2 or pure g-C 3 N 4 . The enhanced photoactivity might be related with the favorable structure resulted from heat-treatment temperature, and the content of g-C 3 N 4 participating in wide optical absorption, separation and transportation of electronic-holes, as well as morphology of composite.
研究领域:
材料科学
·
光催化
·
氢能
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产品关联
DOI
高影响因子
POLYMER BULLETIN
·
2019
·Vol. 77
·期 6
·2855-2871
·
IF 1.858
Zhang Yongjie,Fan Mingshuai,Li Xiaopei
Abstract Long-chain alkyl silicone is a type of modified silicones that finds potential applications in various areas. Long-chain alkyl fluorosilicone (LCAFS) can be considered as a modified long-chain alkyl silicone as it synergistically combines the properties of long-chain alkyl silicone and novel fluorosilicone. As far as we know, reports on the synthesis of LCAFS are rare. In this report, a facile method to synthesize LCAFS was explored. It was found that silicone bearing novel C30-45 alkyls and trifluoropropyl pendent groups, namely (C30-45 alkyl) methylsiloxane/trifluoropropylmethylsiloxane copolymer (TF-AMS), could be synthesized via a simple siloxane equilibration process between silanol-terminated polytrifluoropropylmethylsiloxane and (C30-45 alkyl)methyl silicone, a commercially available silicone that is generally considered as unreactive. The chemical structure of TF-AMS was characterized unambiguously by FTIR, NMR, GPC and DSC. The thermal stabilities of TF-AMS were investigated by TGA. Based on our experimental results, a plausible mechanism for the synthesis of TF-AMS was proposed. Graphic abstract A novel long-chain alkyl fluorosilicone was synthesized via a simple yet efficient siloxane equilibration process.
研究领域:
材料科学
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化学工程
·
高分子化学
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产品关联
DOI
高影响因子
ChemElectroChem
·
2023
·Vol. 10
·期 10
·e202300023
·
IF 4
Xuebing Xu,Yang Song,Chaoquan Hu,Mingyuan Shao,Chang Li
Graphical Ultrathin nanosheets for high-performance asymmetric supercapacitors : Uniform ultrathin hexagonal nanosheets of Co 0.32 Ni 0.68 (OH) 2 is designed and synthesized. It exhibits 12 times higher of specific capacity than Co(OH) 2 . In situ FTIR and DFT calculations confirm the inherent interaction. The assembled Co 0.32 Ni 0.68 (OH) 2 //AC ASC delivers superior performance with a high energy density of 54.97 W h/kg at a power density of 1.68 kW/kg and maintains 33.52 W h/kg at 32.66 kW/kg. In this work, uniform ultrathin hexagonal nanosheets of Co−Ni bimetallic hydroxides are synthesized using a simple green hydrothermal synthesis method. By tuning a Co/Ni mole ratio of 1 : 2, a special nanosheet structure of Co 0.32 Ni 0.68 (OH) 2 was obtained with high interlayer spacing and large pore size. This nanosheet exhibits an enhanced specific capacity as high as 1021.96 C/g at 0.5 A/g, 12 times higher than Co(OH) 2 (83.23 C/g). The high electrochemical performance is attributed to the interfacial interaction between Co 2+ and Ni 2+ , as well as its special nanosheet structure. The advantages of the composition and structure are further confirmed by density functional theory (DFT) calculations. Besides, the energy storage process was visually observed by in situ Fourier transform infrared (FTIR) spectroscopy. Furthermore, an asymmetric supercapacitor (ASC) is assembled by Co 0.32 Ni 0.68 (OH) 2 and activated carbon electrodes. The ASC delivers a high energy density of 54.97 W h/kg at a power density of 1.68 kW/kg and maintains 33.52 W h/kg at 32.66 kW/kg. These results highlight the promising applications of ultrathin Co 0.32 Ni 0.68 (OH) 2 nanosheets as a high-performance electrode material in supercapacitors.
研究领域:
材料科学
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电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2020
·
IF 4.469
Lin Deng,Liuyan Tang,Jinqing Qu
The design and development of macro-photoinitiators applicable to UV system has been attracted increasing attention for their excellent performance of low migration and high compatibility. Herein, four kinds of novel macro-photoinitiators (PI1-PI4) used in UV-curable coatings were synthesized by different isocyanates, 1-hydroxycyclohexyl phenyl ketone (Irgacure 184), 2-hydroxyethyl methacrylate (HEMA) and pentaerythritol triacrylate (PETA). The structures were analyzed by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). Moreover, the photopolymerization kinetics of the macro-photoinitiators were investigated by real-time FTIR. Results revealed that the macro-photoinitiators display higher curing efficiency, lower migration performance and better compatibility with formulation compositions compared to Irgacure 184. On the other hand, the macro-photoinitiators also served as self-initiating oligomers and had good thermal stability with 10 % weight loss temperatures (T10 %) above 299.7 °C. The UV-cured films consisting of oligomers and tripropylene glycol diacrylate (TPGDA) showed excellent physical properties and high curing efficiency and rapid curing rate.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Jiu Chen,Bin Li,Cheng-Yang Cao,Si-Yuan Zhou,Li-Feng Xie,Dan Zhang
As a novel rich nitrogen content material, 5-Amino-1 H -Tetrazole (5AT) has been considerably popularized in the propellants area recently. The pyrolysis is deemed as the prelude of combustion for solid phase 5AT, which plays a crucial role in combustion process and grasping the pyrolysis characteristics will be more beneficial to further explore the combustion properties of 5AT-based propellant. In this paper, several efforts have been made to enhance the pyrolysis behaviors of 5AT, including employing metal particles as catalysts, and modifying the surface treatment method. Due to the calorific value, the boron and copper powder are selected as the potential catalysts. The solvent/non-solvent (S/NS) and solution recrystallization method are compared to explore the impact of these two modification methods. TG-FTIR technique is applied to capture evolved signals of organic compounds to further deduce the most probable decomposition pathway. Moreover, model-free and model-fitting methods are both employed to calculate the kinetic parameters. The results reveal that, for the modified 5AT samples with the same boron powder catalyst, the activation energies and reaction model (all governed by F4) in the initial stage (100–330 °C) are not significantly impacted by these two modification methods. However, during the latter stages (400–750 °C), the catalytic actions of boron powder appear to be more active, and solution recrystallization method exerts better modification effect, the activation energies was reduced 18.3 kJ/mol and 10.9 kJ/mol respectively for the latter stages compared to S/SN method. Also, the reaction model is transformed from n th -dimensional model (D3) to n th -order model (F1) in the third stage. Particularly, the catalytic actions of copper powder results in the simplification of decomposition steps for 5AT, the activation energies was 138.8 kJ/mol and the catalytic effect of which was improved about 25% compared to the catalytic effect of boron powder in the first stage and its reaction model is also found to be changed into F3. It illustrates that copper powder could embody a better catalytic effect than boron powder under the same modification method. The conclusions of this study could provide a worthwhile guidance for the understanding, designs and applications of the 5AT-based propellants.
研究领域:
化学工程
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材料科学
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燃烧科学
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产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2023
·
IF 5.9
Zheng Li,Zuodong Qin,Chunxuan Li,Guimei Zhang,Aozheng Zhang,Sisi Li,Guoqi Liang,Xin Wang,Wufei Tang
Nano calcium carbonate (CaCO 3 ) was successfully treated by tetrabutyl titanate sol together with nickel hydroxide, followed by calcination to form a new kind of flame retardant (Ni-TiO 2 @CaCO 3 ). After study of the Ni-TiO 2 @CaCO 3 structure, it was then introduced into epoxy resin (EP) to improve the flame retardancy and thermal stability. The results shown that NiO and TiO 2 were supported on the surface of the CaCO 3 , and 5 wt% CaCO 3 could enhance the flame retardancy and Ni-TiO 2 @CaCO 3 further increased the flame retardancy of the EP composites. In the cone calorimeter test (CCT), the values of the peak heat release rate (pHRR) and smoke production rate (pSPR) were reduced to 769 kW/m 2 and 0.32 m 2 /s by CaCO 3 from 1101 kW/m 2 and 0.39 m 2 /s of the raw EP respectively. Moreover, pHRR and pSPR values were further decreased to 511 kW/m 2 and 0.25 m 2 /s by Ni-TiO 2 @CaCO 3 respectively. Although the degradation temperature values were lower than that of the control EP, the temperature values at 5 and 50% mass loss for Ni-TiO 2 @CaCO 3 /EP composites were improved compared to the EP. In addition, the char residues value of the Ni-TiO 2 @CaCO 3 / EP composite (23.5%) was obviously improved compared to that of the EP (13.0%) and CaCO 3 / EP composite (16.4%). In addition, the flame retardancy mechanism of the Ni-TiO 2 @CaCO 3 / EP composite was thoroughly analyzed by TGA-FTIR, FITR and Raman methods. This work provides a promising evaluation strategy for utilizing CaCO 3 and its derivatives for possible treatment of EP to enhance its flame retardancy and thermal stability.
研究领域:
材料科学
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高分子科学
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消防安全工程
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产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2022
·
IF 4.831
Bingyao Zhou,Hong Wang,Shui Hu,Qi Yan,Pudun Zhang
Effects of montmorillonite (MMT) on the crystallization behavior of poly(L-lactic acid) (PLLA) were investigated by variable-temperature FTIR spectroscopy. The variations of carbonyl band (1800–1720 cm −1 ) of different PLLA/MMT nanocomposites were focused due to its strong intensity and the involved abundant structure information. Difference spectrometry was used to evaluate the structural variations of PLLA after introducing MMT, and perturbation correlation moving window two-dimensional analysis (PCMW2D) split the temperature range into two sub-regions, i.e., 32–116 ℃ and 116–152 ℃, on the basis of the spectral variation. Two-dimensional correlation spectroscopy (2DCOS) was further applied to such sub-regions in order to find the change order between varied PLLA polymorphs. The results showed that less addition of MMT (≤3%) would lead to a well-exfoliated structure, which not only had no nucleation effect for PLLA, but also delayed the cold crystallization to a higher temperature compared with the one of pure PLLA. However, a higher addition of MMT (≥5%) would lead to an intercalated structure, which acted as a nucleating agent and thus advanced the cold crystallization to a lower temperature. Nevertheless, the introduction of MMT cannot affect the phase transition order between the amorphous, the intermediate, the α′- and the α′-PLLAs based on 2DCOS results.
研究领域:
高分子科学
·
材料化学
·
光谱学
·
纳米复合材料
·
热分析
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2025
·
IF 5.2
Israr Masood ul Hasan,Li Bo,Niu Zhengrong,Gao Dandan,Zhang Yaoling,Muhammad Bilal Shakoor,Muhammad Zubair Nawaz,Yuyu Liu,Jinli Qiao,Nabeel Khan Niazi,Haitao Feng
Use of biowastes for biochar production is an eco-friendly and cost-effective approach for the removal of arsenic (As) from water. However, low adsorption capacity of raw biochar could be a main concern for its practical application. Thus, we explored arsenite (As(III)) sorption to pristine pine cone biochar (PCBC), populous leaf biochar (PLBC) and nano zero-valent zinc-modified PCBC and PLBC (nZVZn-PCBC and nZVZn-PLBC) in aqueous solutions and naturally As-contaminated salt lake water. Biochars were characterized by advanced microscopic and spectroscopic techniques to delineate their surface morphology, chemical properties, and elemental composition. Sorption mechanism was investigated using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy, which indicated that As(III) adsorption mainly controlled by porous structure and ligand exchange of –OH ions on Zn–OH by forming Zn–O–As(III) complexes. The nZVZn-PCBC possessed a higher porous structure and exhibited higher sorption (2.87 mg g −1 , 96 %) in contrast to pristine PCBC (1.95 mg g −1 , 65 %) at pH 7. For sorption kinetics, pseudo-second-order adsorption has given a higher R 2 = 0.99 value. Langmuir isotherm model well-described (R 2 = 0.98) As(III) sorption on nZVZn-PCBC. The nZVZn-PCBC efficiently removed As (84 %) from naturally As-contaminated salt lake water in the presence of co-occurring competing anions. In short, biochar modification with nano zero-valent zinc showed that As can be removed effectively from synthetic as well as real salt lake water.
研究领域:
环境科学
·
水处理
·
纳米技术
·
吸附
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Yang Zhao,Yi He,Siming Yan,Changhua Li,Hongjie Li,Wen Chen,Jing Yan,Guiyang Wu,Xi Yuan
Owing to the increasingly stringent environmental regulations, eco-friendly waterborne epoxy (WEP) coating currently gets much attention as an alternative choice of traditional coating. But the intrinsic problems of WEP, including poor barrier property and lack of long-term anticorrosion performance, was a limitation for its application. Herein, α-zirconium phosphate (α-ZrP) was prepared and exfoliated under mild condition. Then α-ZrP after exfoliation was functionalized by eco-friendly phytic acid (PA) molecular and a novel nano-filler (PZ) was obtained. The test results of the XRD , FTIR, SEM, TEM and XPS indicated that the preparation of nano-materials was successful. Through the EIS test, the outstanding barrier property of WEP incorporating with PZ was proved. Moreover, the excellent long-term anticorrosion performance of WEP incorporating with PZ was also proved by the salt spray test .
研究领域:
材料科学
·
涂层与薄膜
·
环境科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2022
·
IF 8.025
Baoping Zhang,Heng Zhang,Yin Wang,Shiyuan Fang
Amine/quaternary ammonium lignin for adsorption of tungsten was synthesized by amination and quaternization from lignin. The adsorbent was characterized by SEM-EDS and FTIR. The effects of pH, initial concentration of tungsten, adsorption time and dosage of adsorbent on the adsorption effect were investigated. The adsorption mechanism was revealed by SEM-EDS and FTIR and XPS. The results showed that amine/quaternary ammonium lignin was loose and rough and contained a large number of phenolic hydroxyl and amine and quaternary ammonium functional groups. Using the optimum conditions, which included the pH of 4.0 and initial tungsten concentration of 800 mg·L −1 and adsorption time of 960 min, the saturated adsorption capacity of 1 g·L −1 amine/quaternary ammonium lignin for tungsten reached 421.68 mg·g −1 . The adsorption followed Langmuir model and quasi-second-order kinetic model, indicating that the adsorption was monolayer homogeneous chemisorption. When the total concentration of tungsten was 0.005 mol·L −1 and the value of pH was smaller than 4.7, H 2 W 12 O 40 6− was the existing form of tungsten and was adsorbed by electrostatic attraction of hydrogen bond and coordination with amino and ion exchange with Cl − .
研究领域:
环境科学
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2023
·
IF 16.5
Wenqian Yang,Ziqian Xue,Jun Yang,Jiahui Xian,Qinglin Liu,Yanan Fan,Kai Zheng,Peiqin Liao,Hui Su,Qinghua Liu,Guangqin Li,Cheng-Yong Su
The selective electrochemical reduction of CO 2 to CO is a promising solution for the design of carbon-neutral, sustainable processes. Achieving a highly selective single reduction product is still challenging because of the energetically favorable competing hydrogen evolution reaction. We report the fabrication of N-doped sponge-like porous graphitic carbon structures embedded with Fe nanoparticles (Fe@NPC) via the pre-modification of a metal-organic framework (IRMOF-3(Zn)) with carboxyferrocene, followed by pyrolysis . The as-prepared Fe@NPC exhibited a 96.4% CO Faradaic efficiency at –0.5 V RHE and good stability. The exceptional CO 2 reduction performance is attributed to the unique structure of the composite catalyst, which provides abundant hierarchical pores that increase CO 2 adsorption and mass transfer, and active Fe sites that synergistically accelerate the kinetics of CO generation. The in situ attenuated total reflectance-Fourier transform infrared analysis provided proof of the improved ability of Fe@NPC to accumulate the crucial intermediate *COOH compared with other pyrolyzed porous carbons. Fe@NPC was used in a Zn-CO 2 battery that delivered a maximum power density of 3.0 mW cm –2 , evidencing its potential for application in energy-converting devices.
研究领域:
材料科学
·
电化学
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
AAPS PHARMSCITECH
·
2020
·Vol. 21
·期 7
·1-15
·
IF 2.401
Tian Qi,Guo Jianbo,Zhang Qi,Fang Liang,Liu Chao,Xu Hui
The present study aimed to develop a cucurbitacin B microemulsion (CuB-ME) and investigate the mechanism of the enhanced drug skin absorption at the molecular level. Firstly, the pseudo-ternary phase diagrams were developed to evaluate the effect of composition on microemulsion properties systematically. The formulation composition types and ratios of oil phase, surfactant, co-surfactant, and aqueous phase were optimized by an in vitro skin permeation experiment, and the optimized formula was confirmed with the pharmacodynamics study. Furthermore, the molecular mechanism of enhanced skin permeation was investigated using ATR-FTIR and molecular modeling. As a result, the optimized CuB-ME formulation was composed of Azone:Tween 80:ethanol:water = 2.5:16.9:5.6:75.0 ( w / w / w / w ). The oil phase improved skin permeation by disordering the stratum corneum intercellular liquid, while the aqueous phase impacted the particle size of the microemulsion and permeability coefficient of the drug. Besides, the hydration state of skin lipid also enhanced drug permeation by the interaction of water and the polar head of ceramide. The in vitro skin permeation amount was 45.47 ± 10.39 μg/cm 2 , and no significant skin irritation was observed. The pharmacodynamics study demonstrated that CuB-ME had a significant therapeutic effect on the animal tumor model. In conclusion, the CuB-ME was developed successfully and the effect of the oil phase and aqueous phase on drug skin permeation was clarified at the molecular level.
研究领域:
药剂学
·
药学
·
药物递送系统
·
光谱学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）