CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Hao Zhao,Baoyin Xu,Zhanhui Ding,Yanfeng Xue,Jing Yang,Wei Zhao,Yongfeng Li,Bin Yao,Hongdong Li,Yucheng Lan
Bismuth telluride is a widely used commercial thermoelectric material with excellent thermoelectric performances near room temperature. Reducing thermal conductivity is one of the most effective ways to improve performances of thermoelectric materials. In this study, the thermal conductivity of the material was reduced by fabricating porous structures. Highly dense NaCl-(Bi,Sb) 2 Te 3 composites were fabricated by a high-pressure technology. The NaCl phase was then removed from the composites by ultrasonic washing to produce porous structures. The produced (Bi,Sb) 2 Te 3 porous materials possessed excellent thermoelectric properties. The porosity and pore size of the (Bi,Sb) 2 Te 3 porous materials increased with the increasing NaCl content, decreasing the thermal conductivity significantly. An ultra-low lattice thermal conductivity of 0.21 Wm −1 K −1 at 493 K was achieved when the porosity was 39%, almost the lowest lattice thermal conductivity reported for (Bi,Sb) 2 Te 3 bulk materials. The figure of merit ZT value was enhanced to 1.05 at 493 K when the porosity was 25%. Compared with the most compacted samples ( ZT = 0.79 and porosity of 10%) prepared under the same conditions, the ZT value of the porous samples increased by 33%. This study indicated that porous thermoelectric materials can be prepared simply, quickly and efficiently by high-pressure/ultrasonication washing to improve thermoelectric performances, which has evident reference values for preparing other thermoelectric pore materials with enhancing behaviors.
研究领域:
材料科学
·
热电学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2018
·
IF 2.631
Wanjing Cui,Xuebing Fan,Ying Liao,Xiaoping Yu,Yafei Guo,LingZong Meng,Tianlong Deng
The study of the solid-liquid phase equilibrium for (NaCl + NaClO 3 + H 2 O) system is of significance to understand the thermodynamic property of the aqueous solution of ionic membrane electrolysis process to promote the production of sodium hydroxide (caustic soda). The solubilities and the physicochemical properties including density, refractive index and pH for this ternary system at 293.15 and 333.15 K and 0.1 MPa were measured using the isothermal dissolution method. Based on Pitzer ion-interaction model and its extended HW model, the solubility equilibrium constants K sp of NaClO 3 and the mixing ion-interaction parameters ( θ Cl,ClO3 , Ψ Na, Cl,ClO3 ) at 293.15 and 333.15 K were parameterized in this work. The Debye-Hückel limiting slope A ø , the Pitzer single-salt parameters of NaCl and NaClO 3 and the solubility equilibrium constants K sp of NaCl at 293.15 and 333.15 K were taken from the relative temperature-dependence formula in the literature. A comparison shows that the calculated solubilities of the ternary system at 293.15 and 333.15 K agree well with the experimental data. The calculated results of densities and refractive indices using the empirical equations agree well with the experimental data at 293.15 and 333.15 K.
研究领域:
化学工程
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物理化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2020
·
IF 2.627
Ruizhi Cui
Using isothermal dissolution method, the phase equilibrium relationship in quaternary system LiCl + NaCl + KCl + H 2 O and the ternary subsystem LiCl + NaCl + H 2 O at 288.15 K were investigated. Each phase diagram of two systems was drawn. The phase diagram of LiCl + NaCl + H 2 O system contains two solid phase regions of crystallization LiCl·2H 2 O and NaCl. In the phase diagram of LiCl + NaCl + KCl + H 2 O system, there are three crystallization regions: LiCl·2H 2 O, NaCl and KCl respectively. In this paper, the solubilities of phase equilibria in two systems were calculated by Pitzer's model at 288.15 K. The predicted phase diagrams generally agree with the experimental phase diagrams.
研究领域:
化学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2025
·
IF 4.1
Hongguang Kang,Xianwei Hu,Ruidong Guo,Liang Tian,Qiheng Wang,Hanyang Zhang,Aimin Liu,Zhongning Shi,Zhaowen Wang
The electrolysis of Al 2 S 3 in NaCl-KCl molten salts is one of effective ways to achieve sustainable and low-carbon aluminum preparation. The dissolution of Al 2 S 3 into a chloride molten salt promotes the generation of Al-S-Cl complex ions. In this study, the discharge complex ions present in the equimolar NaCl-KCl salt with 1 wt% Al 2 S 3 were analyzed via quantum chemistry calculations at 953 K. On this basis, the cathodic electrochemical behaviors were experimentally investigated via linear sweep voltammetry and chronoamperometry. The results show that Al 2 S 3 Cl − complex ions are discharged on the graphite cathode through a one-step, three-electron transfer reduction process. This reduction is diffusion-controlled and exhibits a quasi-reversible process, with a charge transfer coefficient of 0.271 and a diffusion coefficient of 7.500 × 10 −5 cm 2 ·s −1 .
研究领域:
电化学
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材料科学
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冶金学
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量子化学
·
可持续技术
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2020
·
IF 3.232
Angxin Tong,Xiaojun Tang,Feng Zhang,Bin Wang
In this study, we mainly focused on predictable regularities of the red shift of ultraviolet spectra for β-phenylethylamine (PEA), NaCl and NaOH in aqueous solution. The absorption peaks of the UV spectra near 191 nm of NaCl, NaOH and PEA in aqueous solution moved in the direction of a red shift while the molar absorption coefficient at the peak increased regularly with the increasing solution concentration. These shifts were obtained for solutions with concentrations ranging from 3.68 to 1000 mmol/L for NaCl, from 0.762 to 2000 mmol/L for NaOH, and from 0.0515 to 8.91 mmol/L for PEA. The plots of the logarithm of the solution concentration for NaCl and PEA versus the absorbance at 191 nm and at the peak were linear, and the plots of the logarithm of the solution concentration for NaCl and PEA versus the wavelength at the peak (shifted from 191 nm) were also linear. In addition, the plots of the logarithm of the solution concentration for NaOH that ranged from 0.762 to 1.96 mmol/L versus the absorbance at 191 nm and at the peak were linear as well as the plots of the logarithm of the solution concentration for NaOH that ranged from 1.96 to 2000 mmol/L versus the wavelength at the peak. The slopes of the absorbance at 191 nm of PEA, NaCl and NaOH were somewhat similar to the absorbance at the peak separately, whereas the slopes of the wavelengths at the peak were different from them. Finally, in order to obtain the predictable regularity of the red shift of the UV spectrum for the mixture, 22 ternary mixtures were prepared. The results indicate that the inhibiting effect of hydroxide ions (OH-) caused the wavelength near 206 nm to remain unchanged when the solution concentration of NaOH in the mixture was more than 0.762 mmol/L.
研究领域:
化学
·
光谱学
·
分析化学
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2024
·
IF 2.7
Jianxia Guo,Haichao Li,Shimin Dang
Carbon nanorods exhibit excellent properties in mechanics, electricity, thermology and optics, and have broad application prospects in the frontier of the major areas. In this study, a self-assembly method was employed to synthesize carbon nanorods using sodium hyaluronate (SH) as the carbon source. Using the crystal structure of sodium chloride as a partitioning agent for carbon nanorods micelles. As prepared Samples were characterised and tested using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. The results demonstrated the successful preparation of SH @ NaCl carbon nanorods, with an average diameter and length of approximately 50 nm and 800 nm, respectively, and L/D ratio of 16. The present research strategy emphasises the significance of macromolecule @ salt self-assembly in the synthesis of carbon nanostructures of varying morphologies in different systems.
研究领域:
材料科学
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生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2025
·
IF 5.6
Kang Hongguang,Hu Xianwei,Guo Ruidong,Tian Liang,Wang Qiheng,Yu Jiangyu,Liu Aimin,Shi Zhongning,Wang Zhaowen
Al 2 S 3 electrolysis process in NaCl-KCl molten salts is advantageous for aluminum production due to the low electrolysis temperature, reduced energy consumption, and no greenhouse gas emissions. It is S 2- discharging on the anode and gaseous sulfurs is generated. However, the origin of S 2- from either free S 2- or S 2- in complex ions has rarely been investigated, and the anodic electrochemical mechanism remains unclear. Herein, the discharge sequence of sulfur ions at a graphite anode in equimolar NaCl-KCl molten salts containing 1 wt.% Al 2 S 3 electrolyte at 953 K was investigated by quantum chemical calculations, and the electrochemical mechanism was verified by linear sweep voltammetry, square wave voltammetry, and chronoamperometry. The results indicate oxidation of free S 2- and S 2- in AlSCl 3 2- to produce gaseous sulfurs at the anode, with free S 2- more prone to oxidation than S 2- in AlSCl 3 2- during the anodic electrochemical reaction. The oxidation reactions of both free S 2- and S 2- in AlSCl 3 2- follow one-step two-electron transfer processes. Free S 2- follows a quasi-reversible process, controlled by diffusion, with a charge transfer coefficient of 0.667 and a diffusion coefficient of 3.248 × 10 -5 cm 2 ·s -1 . By comparison, S 2- in AlSCl 3 2- follows an irreversible process, controlled by diffusion, with a charge transfer coefficient of 0.561 and a diffusion coefficient of 1.351 × 10 -5 cm 2 ·s -1 . Overall, these theoretical findings look very promising for future studies and the development of green electrolytic aluminum production processes using NaCl-KCl-Al 2 S 3 molten salts.
研究领域:
电化学
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材料科学
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冶金学
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物理化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2020
·
IF 5.289
Chenyao Li,Shaolong Li,Yusi Che,Junyi Li,Yongchun Shu,Jilin He,Jianxun Song
The reduction mechanism of Nb(V) in molten KCl-NaCl at 1023 K was investigated by a series of electrochemical techniques such as cyclic voltammetry, square wave voltammetry and chronopotentiometry. It was found that there were three steps in the reduction of Nb(V) as Nb(V)→Nb(III)→Nb(I)→Nb, and electrochemical reaction, Nb(V)→Nb(III), is a quasi-reversible diffusion controlled process. The diffusion coefficient of Nb(V) was also obtained by cyclic voltammetry, square wave voltammetry and chronoamperometry. The relationship between current density and the square root of time shows that the nucleation of niobium belongs to the instantaneous nucleation on molybdenum electrode in molten KCl-NaCl-NbCl 5 (0.43 × 10 −3 mol/cm 3 ) at 1023 K at −3.10 V vs. Cl 2 /Cl − . Moreover, the metallic niobium was deposited on molybdenum wire by chronoamperometry, and the products were analyzed by scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX). The results showed that the metallic niobium has a high purity of 99.98%.
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 10
·5725-5732
·
IF 3.108
Baozhong Zhu,Fan Li,Yunlan Sun,Qichang Wang,Yuxin Wu,Zicheng Zhu
To develop the combustion characteristics of aluminum powder in steam, the ignition and combustion process of aluminum powder with different additives (KBH4, ammonium perchlorate (AP) and NaCl) addition at different levels were studied using a transparent pipe furnace. The temperature variation of these samples was measured using a thermocouple, and a high-speed camera was used to record combustion phenomenon. The solid combustion products of these samples with good characteristics were collected to analyze the microstructure and component. The results indicate that the ignition temperature of aluminum powder is decreased by adding these additives or increasing the content of the additive, whereas the maximum combustion temperature is different. When adding 3 wt% KBH4, the maximum combustion temperature reaches up to 1404 °C, which is higher than that of the original aluminum powder. However, upon addition of AP or NaCl the maximum combustion temperature decreases. Simultaneously, the combustion flame of aluminum powder with addition of KBH4 or AP is comparatively intense and bright, whereas the addition of NaCl reduces combustion intensity. The different influence mechanisms of additives on the ignition and combustion of aluminum powder are believed to be responsible for the experimental results.
研究领域:
材料科学
·
燃烧学
·
化学工程
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2023
·
IF 3.9
Lu Zhang,Qiuya Zhang,Hanyu Wu,Xunda Feng,Zhaoxia Jin
Interfacial engineering is a critical pathway for modulating the self-assembled nanostructures of block copolymers (BCPs) during solvent exchange. Herein, we demonstrated the generation of different stacked lamellae of polystyrene-block-poly(2-vinyl pyridine) (PS-b-P2VP) nanostructures during solvent exchange by using phosphotungstic acid (PTA) or PTA/NaCl aqueous solution as the nonsolvent. The participation of PTA in the confined microphase separation of PS-b-P2VP in droplets increases the volume fraction of P2VP and decreases the tension at the oil/water interface. Moreover, the addition of NaCl to the PTA solution can further increase the surface coverage of P2VP/PTA on droplets. All factors impact the morphology of assembled BCP nanostructures. In the presence of PTA, ellipsoidal particles composed of alternatively stacked lamellae of PS and P2VP were formed (named BP), whereas, in the coexistence of PTA and NaCl, they changed to stacked disks with PS-core–P2VP-shell (called BPN). The different structures of assembled particles induce their different stabilities in solvents and different dissociation conditions as well. The dissociation of BP particles was easy because PS chains were only entangled together which can be swollen in toluene or chloroform. However, the dissociation of BPN was hard, requiring an organic base in hot ethanol. The structural difference in BP and BPN particles further extended to their dissociated disks, which makes the cargo (like R6G) loaded on these disks to show a different stability in acetone. This study demonstrated that a subtle structural change can greatly affect their properties.
研究领域:
材料科学
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纳米技术
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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 Electrochemical Science
·
2023
·
IF 1.5
Yan Xia,Zejie Zhu,Linrong Chang,Jianqing Zhang,Fahe Cao,Junxi Zhang
The degradation behavior of AZ91D magnesium alloy with micro-arc oxidation (MAO) coating in NaCl solutions was studied by scanning electrochemical microscopy (SECM). The investigation was carried out at SECM with 10 micron tip using ferrocenemethanol (FcMeOH) as the redox mediator in feedback mode. The variation of localized reactivity of the MAO coating are reflected by tip currents in SECM mapping images, and the generation and evolution of active site/sites on MAO coating are correlated to the concentration of Cl - in the solution and microstructure of the coating. With Cl - concentration increasing, the rate of generation of active sites is accelerated and meanwhile the reactivity of the active sites is enhanced. For the relatively thick and porous coating, there are lots of independent active sites incubating, generating and evolving on coating with the extension of immersion time. While the coating is relatively thin and smooth, the coexistence of slender and lower current peaks and pieces of active regions appears. The reactivity of the artificial line scratch and surrounding areas varied with the increase of immersion time, indicating that the generation, accumulation and dissolution of corrosion product affect the corrosion behavior of AZ91 alloy.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2023
·Vol. 13
·期 7
·1140
·
IF 2.7
Jiuyuan Han,Mengjiao Chi,Liu Yang,Bing Liu,Minmin Mao,Hadi Barzegar Bafrooei,Zhongyan Ma,Yingjie Ren,Feng Shi,Ehsan Taheri-Nassaj,Dawei Wang,Kaixin Song
In this study, dense composites of xNaCl-(1−x)Ni0.5Zn0.5Fe2O4(referred to as NaCl-NZO) and xH3BO3-(0.8−x)Ni0.5Zn0.5Fe2O4-0.2NaCl (referred to as HB-NZO-NaCl) were prepared using the cold sintering process. The objective was to investigate the cold sintering procedure for fabricating ferrite composite ceramics with comparable permeability and dielectric constants suitable for radio-frequency electronic device applications. Optimal cold sintering conditions were determined as 200 °C/30 min/500 MPa with a relative density of 95% for NaCl-NZO and 120 °C/30 min/300 MPa with a relative density of 95.4% for HB-NZO-NaCl. X-ray diffraction and scanning electron microscope analyses confirmed the absence of secondary phases. The resulting composite ceramics showed promising characteristics, with the 0.5NaCl-0.5NZO composition exhibiting a dielectric constant of 6.2 @ 100 MHz, dielectric loss of 0.02 @ 100 MHz, permeability of 2.5 @ 100 MHz, and magnetic loss of 0.001 @ 100 MHz. Similarly, the 0.3HB-0.5NZO-0.2NaCl composition displayed a dielectric constant of 5.9 @ 100 MHz, dielectric loss of 0.02 @ 100 MHz, permeability of 5.1 @ 100 MHz, and magnetic loss of 5 × 10−4@ 100 MHz. These findings indicate potential applications in wireless communication.Keywords:cold sintering;magnetic–dielectric materials;ferrite;dielectric constant
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）