GLASS PHYSICS AND CHEMISTRY
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2021
·Vol. 47
·期 3
·265-269
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IF 0.883
Kai Ma
Abstract In this paper we present a new diamond synthesis method via introduction of highly reactive carbon atoms generated from chemical reactions as the raw materials of diamond. Experiments have shown that by this method the diamond can be synthesized with high yield at pressures as low as 3 GPa and temperatures as low as 900°C. Compared with the conventional phase transformation method, the pressure decreases by about 45% and the temperature decreases by about 35%. XRD, Raman spectroscopy and other characterization analyses have shown that the crystal structure of the diamond synthesized is perfect and the impurity content is low. This is a promising method of diamond synthesis, but requires further optimization.
研究领域:
材料科学
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化学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2021
·
IF 9.028
Bo Zhang,Jing Bai,Yan Zhang,Changhui Zhou,Pengbo Wang,Lina Zha,Jinhua Li,Abdolreza Simchi,Baoxue Zhou
H2S and CO2 are the main impurities in raw natural gas, which needs to be purified before use. However, the comprehensive utilization of H2S and CO2 has been ignored. Herein, we proposed a fully resource-based method to convert toxic gas H2S and greenhouse gas CO2 synchronously into CO and elemental S by using a novel electrochemical reactor. The special designs include that, in the anodic chamber, H2S was oxidized rapidly to S based on the I–/I3– cyclic redox system to avoid anode passivation. On the other hand, in the cathodic chamber, CO2 was rapidly and selectively reduced to CO based on a porous carbon gas diffusion electrode (GDE) modified with polytetrafluoroethylene and cobalt phthalocyanine (CoPc). A high Faraday efficiency (>95%) toward CO was achieved due to the enhanced mass transfer of CO2 on the GDE and the presence of the selective CoPc catalyst. The maximum energy efficiency of the system was more than 72.41% with a current density of over 50 mA/cm2, which was 12.5 times higher than what was previously reported on the H2S treatment system. The yields of S and CO were 24.94 mg·cm–2·h–1 and 19.93 mL·cm–2·h–1, respectively. A model analysis determined that the operation cost of the synchronous utilization of H2S and CO2 method was slightly lower than that of the single utilization of H2S in the existing natural gas purification technology. Overall, this paper provides efficient and simultaneous conversion of H2S and CO2 into S and CO.
研究领域:
环境科学
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能源化学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2020
·Vol. 25
·期 8
·1988
·
IF 3.267
Liming He,Jun Zhou,Yutao Wang,Zhongliang Ma,Chunlin Chen
Energetic binders are a research hot-spot, and much emphasis has been placed on their mechanical properties. In this study, propargyl-terminated ethylene oxide-tetrahydrofuran copolymer (PTPET) was synthesized. Then, PTPET and low-molecular-weight ester-terminated glycidyl azide polymer (GAP) were reacted by the click reaction without using catalysts to obtain a polyether polytriazole elastomer. Through tensile tests, where R = 0.5, the tensile strength reached 0.332 MPa, with an elongation at break of 897.1%. Swelling tests were used to measure the cross-linked network and showed that the cross-linked network regularity was reduced as R increased. The same conclusions were confirmed by dynamic mechanical analysis (DMA). In DMA curves, Tg was around −70 to −65 °C, and a small amount of crystallization appeared at between −50 and −30 °C, because locally ordered structures were also present in random copolymers, thereby forming localized crystals. Their thermal performance was tested by Differential Scanning Calorimeter (DSC) and Thermal Gravimetric Analyzer (TG), and the main mass loss occurred at around 350 to 450 °C, which meant that they were stable. In conclusion, the polyether polytriazole elastomer can be used as a binder in a composite propellant.Keywords:click chemical reaction;PTPET;GAP;polytriazole;thermo-mechanical properties
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
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2017
·
IF 3.458
Chunying Zhu,Yutao Lu,Taotao Fu,Youguang Ma,Huai Z. Li
The gas-liquid two-phase flow and mass transfer with fast chemical reaction in a microchannel were investigated experimentally. Result showed that the bubble volume decreased exponentially with its movement along the channel in a quickly reactable absorbent. The volumetric mass transfer coefficient k L a increased with gas flow rate, while it was insensitive to liquid flow rate under experimental conditions, although the mass transfer coefficient k L increased with liquid flow rate. In slug-bubbly flow regime, the k L decreased when increasing gas flow rate, but inverse tendency was found for slug flow pattern. Both k L and k L a increased with the increase of absorbent concentration. A new correlation for predicting the volumetric mass transfer coefficients k L a was proposed by taking the enhancement factor E of chemical reaction into account.
研究领域:
化学工程
·
传质与反应工程
✓ 已验证
产品关联
DOI
高影响因子
GLASS PHYSICS AND CHEMISTRY
·
2020
·Vol. 46
·期 2
·181-185
·
IF 0.668
Kai Ma
Abstract In this paper, we present a new cubic boron nitride synthesis method via introduction of highly reactive nitrogen and boron atoms generated from chemical reactions as the raw materials of cubic boron nitride, so the system pressure and temperature are reduced significantly compared with the traditional phase transformation method at super high-pressure and high-temperature, and then the production cost of cubic boron nitride can be reduced greatly and the equipment service life can be extended significantly. Experiments have shown that by this method the cBN can be synthesized with high yield at pressures as low as 2.5 GPa and temperatures as low as 450°C. Compared with the conventional phase transformation method, the pressure decreases by about 50% and the temperature decreases by about 64%. Analyses have shown that the crystal structure of the cBN synthesized is perfect and the impurity content is extremely low.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES
·
2016
·Vol. 15
·期 3
·431-439
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IF 2.235
Pozdnyakov Ivan P.,Ding Wei,Xu Jing,Chen Long,Wu Feng,Grivin Vjacheslav P.,Plyusnin Victor F.
Surface complexation between arsenious acid anions (As( iii )) and ferric (hydr)oxides in water is important for the transformation and transfer of inorganic arsenic species. The mechanisms of formation and the photochemistry of dissolved Fe( iii )–As( iii ) complexes in acidic aqueous solution are still unclear. Here, the photooxidation of As( iii ) in the presence of Fe( iii ) ions in acidic media has been investigated by laser flash and steady-state photolysis. At low arsenite concentrations (<1 mM), As( iii ) is oxidized by the ˙OH radical generated by photolysis of the FeOH 2+ complex. At higher arsenite concentrations (>10 mM), photoactive Fe( iii )–As( iii ) complexes are formed ( ϕ 308 Fe ≈ 0.012). At all arsenite concentrations, a white FeAsO 4 colloid is formed during As( iii ) photolysis in the presence of Fe( iii ) ions. Solid Fe( iii )–As( iii ) complexes have been prepared and characterized, and the photochemical transformation of As( iii ) into As( v ) in solid Fe( iii )–As( iii ) complexes has been confirmed. These findings are important for a better understanding of the evolution of As( iii ) species under environmental conditions and should provide guidance for detoxification of As( iii )-polluted water systems.
研究领域:
环境科学
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化学
✓ 已验证
DOI
PubMed
高影响因子
Research
·
2024
·
IF 8.5
Xi Chen,Xianghong Liu,Mohd Yasir Khan,Zuyao Yan,Dezhou Cao,Shifang Duan,Lingshan Fu,Wei Wang
Colloidal molecules, ordered structures assembled from micro- and nanoparticles, serve as a valuable model for understanding the behavior of real molecules and for constructing materials with tunable properties. In this work, we introduce a universal strategy for assembling colloidal molecules consisting of a central active particle surrounded by several passive particles as ligands. During the assembly process, active particles attract the surrounding passive particles through phoresis and osmosis resulting from the chemical reactions on the surface of the active particles, while passive particles repel each other due to the electric polarization induced by an alternating current (AC) electric field. By carefully selecting particles of varying structures and sizes, we have assembled colloidal molecules of symmetric and asymmetric dimers, trimers, and multimers. Furthermore, the coordination number of these colloidal molecules can be regulated in real time and in situ by tuning the interaction forces between the constituent particles. Brownian dynamics simulations reproduced the formation of the colloidal molecules and validated that the self-assembly arises from chemically induced attraction and electrical dipolar repulsion. This strategy for reconfigurable colloidal assemblies poses the potential for designing adaptive micro-nanomachines.
研究领域:
材料科学
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物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ATMOSPHERIC ENVIRONMENT
·
2024
·
IF 4.2
Hongxing Yang,Wangjin Yang,Jiawei Ma,Chong Han
The heterogeneous reactions of SO 2 on organic aerosols (OA) have been proposed as a significant source of sulfates. The photochemical conversion of SO 2 to sulfates on the surface of light-absorbing OA, i.e., brown carbon (BrC), remained slight understanding. Herein, the photochemical uptake of SO 2 on typical BrC species, including aromatic carbonyl compounds (ACs), polycyclic aromatic hydrocarbons (PAHs) and phenols (PHs), was systematically investigated by a flow tube reactor. Light can significantly promote the uptake of SO 2 on all BrC species used here, especially for ACs. The initial and steady-state uptake coefficients (γ i and γ ss ) of SO 2 exhibited positive relationships with the light intensity, whereas they negatively correlated with the initial SO 2 concentration. Significant sulfate formation was clearly observed with in situ attenuated total internal reflection infrared (ATR-IR) spectrometer, and H 2 O and O 2 had obvious enhancement effects on the sulfate production. Photoinduced •OH, which primarily originated from •O 2 − that was generated through an electron transfer process on BrC under irradiation, was determined to be a key driver for the oxidation of SO 2 to sulfates. Finally, SO 2 lifetime and sulfate formation rate were evaluated on the basis of experimental results, highlighting potential contributions of BrC photochemistry to atmospheric SO 2 loss and sulfate sources.
研究领域:
大气科学
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环境化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 23
·13583-13590
·
IF 3.119
Ju Huang,Yaqi Fan,Guanqun Zhang,Yanhang Ma
Introduction of meso-/macropores into the intrinsic microporous framework of zeolites has raised substantial interest in catalytic reactions with bulky reactants. Herein, we report the formation of secondary meso-/macropores in Silicalite-1 zeolite by a solvent-free mechanochemical grinding process. The strategy allows the preservation of high crystallinity and microporosity of the pristine zeolite, and the generation of mesopores at room temperature and marcopores at higher temperatures. The roles of the tetrapropylammonium bromide (TPABr) and ammonium fluoride (NH4F) have been proposed and demonstrated. A protective layer is formed by TPA+ ions bonded with the surficial defects to shield the outer surface from the direct attack by F−. Instead, F− diffuses into the micropore system in a local aqueous environment within zeolite formed by the mechanochemical reaction. As a result, freely diffused F− selectively dissolves zones with structural defects to form secondary pores inside the zeolite. Moreover, this strategy proves highly effective in encapsulation of nanoparticles (Pt, Co) in the meso-/macropores of Silicalite-1 zeolite, forming a yolk–shell composite catalyst for potential applications.
研究领域:
催化科学
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材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Energy Storage Materials
·
2018
·
IF 0
Qian Liang,Fuming Chen,Shaofeng Wang,Qiang Ru,Qinyu He,Xianhua Hou,Ching-yuan Su,Yumeng Shi
Renewable energy-related technologies have become more important due to the increasing energy consumption. Herein, we put forward a novel organic flow desalination battery (ORFDB) using redox-active organic molecule electrolyte materials dissolved in the aqueous sodium chloride feed. Riboflavin-5’-phosphate sodium salt dihydrate (FMN-Na) is used as the anolyte, and the catholyte is 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO). Sodium and chloride ions in salt feed were moved respectively to anolyte and catholyte by electrochemical reaction of electrolytes during the charge process, and return to the feed during the discharge process. This ORFDB system possesses the stable stability up to fifty cycles and the excellent rate performance. This ORFDB exhibits the cost-effective renewable energy storage and the possibility of salt removal based on the electrochemistry of organic molecules.
研究领域:
能源科学
·
电化学
·
材料科学
✓ 已验证
产品关联
DOI
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2023
·
IF 11.4
Jinzhao Wang,Di Huang,Fengxia Chen,Jianhua Chen,Hongyu Jiang,Yifan Zhu,Chuncheng Chen,Jincai Zhao
Fe(III) and carboxylic acids are common compositions in atmospheric microdroplet systems like clouds, fogs, and aerosols. Although photochemical processes of Fe(III)–carboxylate complexes have been extensively studied in bulk aqueous solution, relevant information on the dynamic microdroplet system, which may be largely different from the bulk phase, is rare. With the help of the custom-made ultrasonic-based dynamic microdroplet photochemical system, this study examines the photochemical process of Fe(III)–citric acid complexes in microdroplets for the first time. We find that when the degradation extent of citric acid is similar between the microdroplet system and the bulk solution, the significantly lower Fe(II) ratio is present in microdroplet samples due to the rapider reoxidation of photogenerated Fe(II). However, by replacing citric acid with benzoic acid, no much difference in the Fe(II) ratio between microdroplets and bulk solution is observed, which indicates distinct reoxidation pathways of Fe(II). Moreover, the presence of •OH scavenger, namely, methanol, greatly accelerates the reoxidation of photogenerated Fe(II) in both citric acid and benzoic acid situations. Further experiments reveal that the high availability of O2 and the citric acid- or methanol-derived carbon-centered radicals are responsible for the rapider reoxidation of Fe(II) in iron–citric acid microdroplets by prolonging the length of HO2•- and H2O2-involved radical reaction chains. The results in this study may provide a new understanding about iron–citric acid photochemistry in atmospheric liquid particles, which can further influence the photoactivity of particles and the formation of secondary organic aerosols.
研究领域:
大气科学
·
环境化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Yezi Hu,Duoyue Tang,Zewen Shen,Ling Yao,Guixia Zhao,Xiangke Wang
Photocatalytic extraction of uranium from nuclear wastewater and seawater is a highly promising strategy to avoid environmental pollution and effectively recover uranium resources. Herein, we propose a novel strategy of photochemical for efficiently and high selectively extracting uranium from aqueous solution. The excited UO 2 2+ at a suitable pH range were utilized for initiating the formation of hydrogen peroxide, which then directly reacted with UO 2 2+ to form solid studtite (UO 2 )O 2 ∙4 H 2 O. This photochemically triggered extraction approach could remove ∼100.0% of UO 2 2+ from aqueous solution with U(VI) concentration of 10.0–200.0 ppm, and 62.7% of UO 2 2+ from U(VI)-spiked real seawater after 24 hrs-irradiation under visible light even without additional electron-donor agents. The highly selective and high extraction efficiency towards uranium ranged in extremely wide concentrations demonstrated the powerful application potential in both the removal of uranium from nuclear wastewater and the extraction of uranium from seawater. Data Availability Data will be made available on request.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）