FUEL
·
2024
·
IF 6.7
Ji Mi,Peilun Wang,Hongshang Wang,Chongkun Shao,Zhiyuan Yuan,Jingkai Ma,Yongsheng Guo,Xufeng Lin,Wenjun Fang
Endothermic hydrocarbon fuels (EHFs) with high heat sink have revolutionized the thermal management technology of hypersonic aircraft over the past decades. In this work, highly stable quasi-homogeneous systems as a novel type of potential EHFs are introduced by dispersing water-rich multifunctional nanospheres in hydrocarbons. Studies conducted using cryo-transmission electron microscopy, dynamic light scattering and small-angle X-ray scattering have demonstrated that nanospheres with diameter less than 100 nm can be solubilized into hydrocarbons to form semi-transparent systems. They resist phase separation, remain stable under extreme centrifugal forces (exceeding 8000 RCF), and have low freezing points (subcooling temperature below −40 °C). In these quasi-homogeneous systems, the amphiphilic macromolecules within the multifunctional nanospheres serve dual roles: they stabilize the nanospheres and initiate the thermal cracking of the fuel, while the water component mitigates coking tendencies and contributes to the high heat sink. Ultimately, this novel fuel can achieve up to 19 % improvement in heat sink (from 3.42 MJ·kg −1 to 4.05 MJ·kg −1 at 3.5 MPa) and a 96.8 % reduction in coke formation (at 700 °C) with only a 9 % loss in volumetric heat value, without the need of catalysts.
研究领域:
材料科学
·
航空工程
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2024
·
IF 3.1
Jiao Feng,Peng Lin,Simeng Xiang,Xiang Lin,Feng Liu,Hongyu Yang,Xiaming Feng,Chaojun Wan
In this work, alkali metal hydrates, barium hydroxide octahydrate (BHO) and sodium acetate trihydrate (SAT) were added into epoxy resin (EP) to prepare a series of flame-retardant EP composites. It showed that EP samples can pass the V-0 rating of UL-94 when the amount of hydrated salt exceeds 45 wt%. When the additional amount of SAT is 50 wt%, the LOI of the EP sample increases to as high as 39% compared to 19% of pure EP. In addition, the time to ignition (TTI) of EP with 50 wt% SAT was prolonged to 157 s from 63 s of pure EP, which can provide valuable time for fire escape. The peak heat release rate (PHRR) was reduced by 63.9% compared with that of pure EP (from 1392.4 kW/m 2 to 502.18 kW/m 2 ), which indicated that phase change heat absorption plays a crucial role in reducing fire hazards of EP.
研究领域:
材料科学
·
防火安全
✓ 已验证
产品关联
DOI
高影响因子
ACTA ASTRONAUTICA
·
2022
·
IF 2.954
Wenli Yu,Weixing Zhou,Zhenjian Jia,Zhixiong Han
The regenerative cooling technique with endothermic reactions is prospective for scramjet engines, in which the convective heat transfer characteristics are necessary for the thermal system design. In this work, the turbulent heat transfer characteristics of hydrocarbon fuels with endothermic chemical reactions were experimentally and numerically investigated. Three kinds of surrogates and two different pressures were employed to obtain various chemical endotherms, and the distributions of physical properties and dimensionless parameters were analyzed in the chemical region. Results showed that endothermic chemical reactions improved the convective heat transfer performance, even though the variations of fluid Reynolds number and Prandtl number brought by chemistry were small. Then, a dimensionless parameter was proposed to describe the proportion of chemical endotherm capacity. The numerical results revealed that the natural logarithm of Nusselt number enhancement changed linearly with the proposed dimensionless parameter, and the slopes were irrelevant to reactant types or chemical conditions. Last, by modifying the Dittus-Boelter correlation, a novel Nusselt number correlation was put forward for the endothermic reacting flow. Based on the analysis of the existing data and the formula form, continuously increasing the fuel chemical endotherm might bring a smaller benefit of Nusselt number augmentation.
研究领域:
航空航天工程
·
热能工程
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2020
·Vol. 326
·期 2
·1307-1321
·
IF 1.137
Yin Na,Ai Yong,Xu Yuanxin,Ouyang Yanquan,Yang Pengfei
Magnetic carbon aerogels were prepared from inexpensive and readily available winter melon to adsorb U(VI). The morphology, structure, magnetism, characteristic functional groups and chemical bonds of magnetic carbon aerogels were characterized by TEM, SEM, XRD, BET, VSM, FT-IR, XPS. Under the condition of 303 K and pH 6, magnetic carbon aerogel reached adsorption equilibrium within 120 min, with the adsorption capacity of 230.3 mg g –1 , much higher than that of carbon aerogel (77.9 mg g –1 ), which is the function of Fe–O. The good magnetism of magnetic carbon aerogels allows it to be easily separated from the solution by applying magnetic field. The adsorption isotherm data accord with Langmuir isothermal model. Adsorption is a spontaneous and endothermic process.
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
Materials
·
2020
·Vol. 13
·期 21
·5047
·
IF 3.057
Jun Cao,Peng Wang,Jie Shen,Qi Sun
Here, using Fe3O4@SiO2as a precursor, a novel core-shell structure magnetic Cu2+adsorbent (Fe3O4@zeolite NaA) was successfully prepared. Several methods, namely X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), Transmission electron microscope (TEM), Brunauer Emmett Teller (BET) and vibrating sample magnetometry (VSM) were used to characterize the adsorbent. A batch experiment was conducted to study the Cu2+adsorption capacity of Fe3O4@zeolite NaA at different pH values, contact time, initial Cu2+concentration and adsorbent does. It is found that the saturated adsorption capacity of Fe3O4@zeolite NaA on Cu2+is 86.54 mg/g. The adsorption isotherm analysis shows that the adsorption process of Fe3O4@zeolite NaA to Cu2+is more consistent with the Langmuir model, suggesting that it is a monolayer adsorption. Adsorption kinetics study found that the adsorption process of Fe3O4@zeolite NaA to Cu2+follows the pseudo-second kinetics model, which means that the combination of Fe3O4@zeolite NaA and Cu2+is the chemical chelating reaction. Thermodynamic analysis shows that the adsorption process of Fe3O4@zeolite NaA to Cu2+is endothermic, with increasing entropy and spontaneous in nature. The above results show that Fe3O4@zeolite NaA is a promising Cu2+adsorbent.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
SOLAR ENERGY
·
2024
·
IF 6
Lili Yang,Jinrui Zhang,Chong Li,Gang Wang,Shuxian Duan,Kai Zhang
Solar thermal power generation has been widely employed as an effective method for efficiently harnessing solar energy, with solid heat-collecting particles serving as the medium for collecting and storing solar energy, thus holding significant developmental potential. However, challenges such as high thermal radiation losses and inadequate high-temperature stability have hindered the further advancement of solid heat-collecting particles. The present study addresses these challenges by utilizing solid waste fly ash to prepare solar-selective absorbing solid heat-collecting particles. Specifically, particles sintered at 1070℃ exhibit impressive characteristics, including an average solar absorptance of 93.26 % at room temperature, an emissivity in the mid-infrared range of 68.12 %, and a specific heat capacity of 0.82 J/(g·℃). Moreover, rigorous high-temperature stability tests demonstrate that these particles maintain a stable solar absorptance in the ultraviolet–visible-near-infrared range, consistently around 93.26 %. Additionally, the particles exhibit outstanding wear resistance and stability, further enhancing their suitability for practical applications. This research achieves the dual objectives of environmental sustainability and cost reduction by utilizing solid waste materials, while the preparation process remains simple, bolstering the feasibility of implementing these findings in real-world scenarios. In summary, this study effectively addresses the challenges of high thermal radiation losses and poor high-temperature stability in solid heat-collecting particles for solar thermal power generation.
研究领域:
能源科学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Qinghong Ji,Xinxin Sheng,Xiaolong Li,Shuang Liu,Qiufei Chen,Pengzong Guo,Yabi Yang,Youyou Huang,Guoliang Zhang,Xiang Lu,Jinping Qu
Infrared stealth materials are in increasing demand with the development of infrared detection technology. However, most reported materials focus solely on emissivity control or temperature control, resulting in brief and less ideal infrared stealth effect. Herein, a double layer MXene@polyvinyl alcohol (PVA)/phase change capsules (PCC) aerogel composite inspired by the skin-fat structure of camel for infrared camouflage was successfully fabricated via a facile freeze-drying followed by spraying method. The PVA/PCC aerogel composite with high latent heat (155.2 J/g) and strong mechanical properties (772.6 kPa), obtained by an in-situ one-step method, is adopted as a temperature control layer, benefiting from the prominent thermal insulation of porous structure and effective heat absorption of PCC. The low emissivity (0.249) of the MXene layer on the surface of aerogel composite makes its radiation temperature recognized by the thermal imager much lower than its actual temperature. By integrating thermal insulation, heat absorption and emissivity reduction strategies, MXene@PVA/PCC aerogel shows no difference with the background in the infrared thermal imager (radiation temperature difference less than 10 °C), achieving superior infrared stealth for medium and low temperature scenarios, and provides novel ideas for developing more high-performance infrared stealth materials.
研究领域:
材料科学
·
纳米技术
·
热工程
·
红外技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Chuyuan Huang,Xianfeng Chen,Bihe Yuan,Hongming Zhang,Sheng Shang,Qi Zhao,Huaming Dai,Song He,Ying Zhang,Yi Niu
Flame propagation characteristics of wood dust deflagration and suppression mechanism of ultrafine powders are investigated systematically. The deflagration reaction intensity of wood dust increases firstly and then decreases with the increase in dust cloud concentration. This is due to factors such as oxygen supply, positive feedback among flame characteristic parameters. Thus, there is an equivalent dust concentration for greatest deflagration intensity. Nano-sized ultrafine zirconium hydroxide (Zr(OH) 4 ) and silicon dioxide (SiO 2 ) powder are introduced to suppress wood dust deflagration at the equivalent concentration. It is found that Zr(OH) 4 has a suppression effect of endothermic decomposition to generate zirconia (ZrO 2 ), dilution of oxygen and absorption of free radicals; while SiO 2 exerts suppression effect due to its high melting point and heat absorption. The suppression performance of Zr(OH) 4 is better than that of SiO 2 . This is because that Zr(OH) 4 and ZrO 2 have a catalytic carbonization effect. It can not only improve thermal stability of wood particles by catalyzing production of high-temperature resistant residuals, but also promote the formation of catalytic sites to reduce crystallite size of carbon layer on wood particles surface, weakening heat and mass transfer between particles.
研究领域:
安全工程
·
燃烧学
·
粉尘爆炸防控
·
材料化学
·
热力学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Yitong Dai,Chongkun Shao,Xinyang Chen,Shu Yan,Yongsheng Guo,Ji Mi,Wenjun Fang
To solve the heat management problem of supersonic aircraft, endothermic hydrocarbon fuels (EHFs) have been developed as both a coolant and a propellant. The pseudohomogeneous catalyst is an efficient way to improve the heat sink of EHFs. In this work, hydrocarbon soluble macrocyclic calixarene compound C-undecyl calix[4]2-(propylsulfanylmethyl)-resonrcinarene (C11–SC3) was synthesized and used as a stabilizer for hydrocarbon-dispersed Pt nanoparticles (Pt@C11–SC3). The morphological characterization results indicate that Pt nanoparticles are encapsulated by the calixarene, which helps the fabrication of ultrasmall Pt@C11–SC3. Ethylcyclohexane (ECH) was selected as a model substrate of EHFs to construct the Pt@C11–SC3/ECH nanofluid system for pseudohomogeneous catalytic cracking. The cracking test of the Pt@C11–SC3/ECH nanofluid was carried out in a batch reactor and a flow reactor under constant volume and pressure conditions. The distribution of cracking products displayed a significant improvement in terms of cracking conversion and a preferred heat absorbed reaction pathway, leading to a higher heat sink. There was a 16% maximum increase in heat sink in the constant pressure cracking tests with the addition of 0.01 wt % Pt@C11–SC3 at 700 °C. It provides a helpful method for heat sink enhancement of EHFs.
研究领域:
化学工程
·
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED MICROBIOLOGY
·
2021
·Vol. 131
·期 5
·2270-2279
·
IF 3.772
Wang A.,Liu C.,Ge X.,Meng W.,Pi Y.,Liu C.
AimsThe adsorption behaviour and mechanisms of the surface modified activated carbon with bacteria was evaluated.Methods and Results16S rRNA was employed to identify the hydrocarbon‐degrading bacteria. The bacteria was characterized by TEM and electron microscope. The surface modified activated carbon with bacteria was characterized by SEM. The adsorption behaviour was tested by static adsorption and dynamic adsorption.ConclusionThe adsorption efficiency of the modified activated carbon was high when pH was weak acidic, and the adsorption capacity increased with the increase of temperature ranging from 20 to 35°C. The adsorption capacity peaked at 234·6 mg g−1 at 25°C, which was sixfold higher than that of activated carbon. The pseudo‐first‐order kinetic can more accurately assess Congo red adsorption on the two adsorbents. The adsorption of Congo red by bacteria surface modified activated carbon fitted well with the Langmuir's model. The adsorption process was endothermic, and the biological floccules were formed during the adsorption. The physical adsorption is the main driving force.Significance and Impact of the StudyThe results indicate that the bacteria surface‐modified activated carbon can be used effectively as an adsorbent to eliminate Congo red from aqueous solutions.
研究领域:
环境科学
·
微生物学
·
化学工程
·
水处理
✓ 已验证
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Yi Wu,Anqi He,Da Li,Limin Yang,Yizhuang Xu,Yukihiro Ozaki,Isao Noda
This study investigates single-crystal structures of Lu3+/erythritol and nine rare earth–glycerol complexes, revealing deprotonation of normally inert OH groups via μ2-bridging (so-called DIOμ2 phenomenon). The pH drops upon alditol addition correlate with the deprotonation extent, showing increased deprotonation with decreasing lanthanide ionic radius (lanthanide contraction) and exceptionally high deprotonation for Sc3+. In all the rare earth/alditol complexes with the DIOμ2 phenomenon, two μ2-bridges merge into an M2O2 cluster (M is a rare earth ion) that is not very stable due to the Coulombic repulsion between two M3+ and between two O–. To stabilize the M2O2 cluster, the formation of more auxiliary five- and six-membered chelating rings between rare earth ions and alditol ligands is needed. Increment of the number of auxiliary five- and six-membered chelating rings favors the DIOμ2 reaction. This is the reason why the DIOμ2 reaction shows a progressively enhanced tendency when the alditol ligands change from myo-inositol to glycerol to erythritol and galactitol. The reaction is endothermic, as an increased temperature enhances deprotonation. The above results may be useful in the rational design of catalysts that efficiently activate inert OH bonds and facilitate related chemical processes.
研究领域:
无机化学
·
配位化学
·
晶体学
·
物理化学
·
催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Hongwei Wang,Fang Wu,Zhiheng Wang,Yang Wang,Shufang Zhang,Haijun Luo,Zhiqin Zheng,Liang Fang
Chromium (VI) removal is crucial to the safety of water resources, but there is still a lack of effective and fast dislodge methods, especially the on-site rapid remediation and emergency removal technology . Herein, the monolayer (ML) Ti 3 C 2 T x nanosheets (NSs) were prepared to remove Cr (VI) from water. The solution sample of the two-dimensional (2D) Ti 3 C 2 T x NSs demonstrate ultrafast adsorption kinetics (the concentration decreasing from 300 to 3 mg L −1 in 10 min) and impressively high capacity (1483 mg g −1 ), which is several times higher than that of the most reported Cr (VI) adsorption by Ti 3 C 2 T x . The analysis of the adsorption kinetics and isotherm models indicates that the adsorption reaction is endothermic, with physical and chemical adsorption coexisting (mainly monolayer chemical adsorption). The joint study of the experimental analysis and theoretical calculation based on the density functional theory (DFT) demonstrates that the extraordinary removal performance of Cr (VI) is due to the synergetic effect of reduction reaction removal and electrostatic adsorption. It is found that the Cr (VI) is mainly reduced by the OH- terminals on Ti 3 C 2 , and the detoxified Cr (III) is anchored on the surface of Ti 3 C 2 T x through complexation reaction with O terminal. The advantages of ultrafast adsorption kinetics and extra-high adsorption capacity of the single-layered Ti 3 C 2 T x for Cr (VI) removal make it a remarkable candidate for rapid and urgent removal of Cr (VI) wastewater.
研究领域:
环境科学
·
材料科学
·
化学工程
·
水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）