APPLIED THERMAL ENGINEERING
·
2016
·
IF 3.043
Aihong Du,Huiwen Yuan,Wei Liao,Haobo Zhou,Chunhua Lu,Zhongzi Xu
Cost-effective thermal energy storage materials are vital to the application of solar thermal power plants . One focus of this paper is improving thermal and mechanical properties of the thermal energy storage materials; the second focus lies in reducing the investment cost. On the basis of aluminate cementitious composites with 1 wt% nano-SiO 2 , 1 wt% nano-Cu and 15 wt% Cu powders, we introduced different wt% (0, 5, 10, and 15) of Fe powders to gradually replace 15 wt% Cu powders. The samples were heated at 105, 350, and 900 °C, respectively. As a result, when the content of Fe powders substitution was 10 wt%, volume heat capacity, thermal conductivity and compressive strength of the composites after heat-treatment at 900 °C were up to 2.38 MJ m −3 K −1 , 1.45 W m −1 K −1 , and 73.8 MPa respectively, which were 26.6%, 26.1%, and 24.0% higher than those of the composites with 15 wt% Cu powders. At the same time, the investment of the composites with 10 wt% Fe powders substitution was reduced almost 62.0%, compared with that of the composites with 15 wt% Cu powders. In addition, XRD and MIP were employed to characteristic the mineral phases and the pore structures of the aluminate cementitious composites, respectively.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2024
·
IF 2.2
Zhuoxue Xie,Huimin Yan,Henan Dai,Yan Kou,Xuemei Yan,Ying Tian,Quan Shi
Fatty acids are commonly used as phase change materials (PCMs) for thermal energy storage due to their high latent heat, non-toxicity, and biocompatibility. However, the thermodynamic properties of fatty acids have not been systematically studied, especially for their heat capacity data over a wide temperature range. This limitation greatly restricts their practical applications in designing and constructing fatty acids based PCMs and corresponding thermal management techniques. Herein, the heat capacities of a series of fatty acids (octanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, and octadecanoic acid) have been measured using a combined relaxation, adiabatic, and differential scanning calorimetry techniques over a temperature range from 1.9 K to 380 K. The corresponding thermodynamic functions and phase transition thermodynamic parameters have been calculated based on heat capacity data fitting. Additionally, the thermal stability and thermal conductivity of these fatty acids have also been determined using a thermogravimetric analysis instrument and a thermal constant analyzer, respectively. These obtained thermodynamic properties can provide crucial fundamental information for the study and application of fatty acid PCMs and related thermal energy storage techniques.
研究领域:
材料科学
·
热力学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2018
·Vol. 20
·期 14
·9130-9138
·
IF 3.906
Xue Wang,Chen Xu,Xiaoyi Tao,Tianxiang Yin,Zhiyun Chen,Weiguo Shen
The heat capacities of nine binary room temperature ionic solutions {[C4mim][BF4] + 1,2-butandiol}, {[C8mim][BF4] + 1-pentanol}, {[C8mim][BF4] + 2-pentanol}, {[C8mim][BF4] + 1-hexanol}, {[C8mim][BF4] + 1-heptanol}, {[C8mim][PF6] + 1-propanol}, {[C8mim][PF6] + 1-butanol}, {[C8mim][PF6] + 2-butanol} and {[C8mim][PF6] + tert-butanol} are reported herein. The combination of the data obtained with the corresponding measured coexistence curves infers that the critical asymmetry parameter of the coexistence curves linearly varies with the molar volume ratio of the two components for each of the studied binary ionic solutions after the heat capacity contribution is considered. This indicates the importance of the heat capacity contribution to the critical asymmetry. For further analysis of the critical characteristics of the ionic solutions, a large amount of experimental data was collected and systematically discussed in detail regarding which critical character is important in the binary ionic solutions. A general increasing tendency for the RPM (restricted primitive model)-rescaled critical parameters with the relative permittivity εr,c of the solvent at the critical temperature of the corresponding system was found. This is attributed not only to the screening effect of the solvent medium, but also to solvophobic interactions, which both increase with εr,c. This study also demonstrates that the critical amplitudes increased, while the relative contribution of the heat capacity to the asymmetry of the coexistence curve decreased with an increase in εr,c.
研究领域:
物理化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Weiwei Wang,Yibing Cai,Mingyue Du,Xuebin Hou,Jingyan Liu,Huizhen Ke,Qufu Wei
It is important to explore and develop multifunctional phase change composites with high latent-heat capacity and photothermal conversion capability. A novel ultralight and flexible carbon foam (CF)-based phase change composite was fabricated by encapsulating n-eicosane into a CF skeleton that had been precoated with titanium(III) oxide (Ti2O3) nanoparticles (NPs). Morphological structures, as well as the properties of leakage-proof, thermal energy storage, temperature regulation, and photothermal conversion, of the fabricated phase change composites were investigated. The results indicated that the flexible CF skeleton derived from melamine foam (MF) through stabilization in air followed by carbonization in nitrogen was highly porous, which ensured excellent mechanical support and large mass ratio of n-eicosane for the composites. The loading percentage of n-eicosane as high as 84% which acted as thermal storage unit guaranteed high latent-heat capacity and good temperature regulation property of the composite; the melting/crystallization temperatures and enthalpies of the corresponding composite was 36.4/33.7 °C and 200.1/200.6 kJ·kg–1, respectively. The CF skeleton modified with Ti2O3 NPs endowed the fabricated phase change composites with enhanced leakage-proof property, photothermal conversion capability, superior thermal reliability, and temperature regulation ability. Therefore, the resultant phase change composites are believed to have promising and potential applications in solar thermal-energy storage, waste-heat recovery, and infrared stealth of military targets, and so forth.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Energy Storage
·
2022
·
IF 8.907
Zeyang Kang,Yaohui Shi,Hui Liu,Xiangyang Liu,Maogang He
Electrical generators transducing and concentrating solar power to heat and then to electricity require a material with good thermophysical properties to store heat when there is no sunlight. Here, LiCl-KCl-ZnCl 2 and LiCl-KCl-MgCl 2 were observed for their capacity to store energy by the change in sensible heat content as a function of temperature. The ternary phase diagrams of the two salts were predicted using a thermodynamic model . Three eutectic points for LiCl-KCl-ZnCl 2 and four eutectic points for LiCl-KCl-MgCl 2 were predicted and experimentally verified. The heat capacity and thermal stability of the seven eutectic mixtures were measured to evaluate their heat storage capacity and operating temperature range. LiCl-KCl-ZnCl 2 (13.86 % mol-40.63 % mol-45.51 % mol) and LiCl-KCl-MgCl 2 (47.29 % mol-44.33 % mol-8.38 % mol) were found to be the best choices for heat storage materials, which have low melting points of 451.8 K and 612.8 K, large heat capacity of 1.25 J/g·K and 1.80 J/g·K, and wide operating temperature range from room temperature to higher than 823 K, respectively.
研究领域:
材料科学
·
热力学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED THERMAL ENGINEERING
·
2022
·
IF 6.465
Zhiheng Zheng,Tao Shi,Huan Liu,Dezhen Wu,Xiaodong Wang
Solar energy is the cleanest and most abundant renewable energy source that can be utilized to displace fossil fuels and provide an effective solution for future energy shortage and climate change. Aiming at enhancing the capture efficiency of solar photothermal energy, we developed a novel type of phase-change composites based on polyimide (PI)/phosphorene (PR) hybrid aerogel and polyethylene glycol (PEG). The composites were prepared by fabricating a series of PI/PR hybrid aerogels with different loadings of PR nanosheets using freeze-drying and thermal imidization techniques, followed by vacuum impregnation of PEG as a phase change material into the aerogel framework. The obtained hybrid aerogels exhibited a lightweight nature with a density of 21.9 mg·cm −3 when 16 wt% PR nanosheets were incorporated, resulting in an extremely high PEG loading of 4067% in the aerogel system. The combination of PI and PR nanosheets leads to a significant enhancement in solar light absorption and photothermal energy conversion for the hybrid aerogel/PEG composites. The loading amount of PEG was also improved remarkably due to an increase in the volume capacity of the hybrid aerogels resulting from the introduction of PR nanosheets. The resultant hybrid aerogel/PEG composites not only exhibit a high latent-heat capacity of over 170 J·g −1 and a high photothermal conversion efficiency of 82.5%, but also show good thermal impact resistance to keep their original shape and form well after heating at 80 °C for 20 min and maintain a high thermal cycle stability after thermally cycled for 500 times. These superior performances make the hybrid aerogel/PEG composites capable of dealing with a wide range of applications in solar photothermal energy capture and storage. This study provides a promising strategy for the design and development of high-performance and lightweight composite PCMs to meet the requirement of applications for efficient utilization of solar energy.
研究领域:
材料科学
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可再生能源
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纳米技术
·
太阳能工程
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2024
·
IF 8.3
Xin Zhang,Shanshan Yang,Huanzhi Zhang,Huan Liu,Xiaodong Wang
Solar-powered interfacial evaporation is considered as an emerging innovative technology for seawater desalination; however, it suffers from insufficient evaporation efficiency under intermittent solar irradiation. Aiming at realizing sustainable solar-powered seawater desalination for clean water production, we have designed a new type of watermelon-like phase-change microcapsules as a photothermal absorbent material for solar interfacial evaporators. This type of phase-change microcapsules was prepared through rational layer-by-layer microencapsulation with a ZrO 2 nanoparticle-containing n -docosane core as a phase-change material (PCM) for solar photothermal harvest and prompt thermal response, a ZrO 2 shell for the leakage prevention of the molten n -docosane core, and a polydopamine coating layer together with its surface-decorated phosphorene nanoflakes for high-efficient sunlight absorption and fast water transportation. The resultant microcapsules are featured by a watermelon-like microstructure as confirmed by transmission electron and scanning electron microscopy. They also exhibit a high light absorption efficiency of 84.95 %, a high latent heat capacity of 146.2 J g −1 , and good wettability. Equipped with the watermelon-like phase-change microcapsules, the developed solar interfacial evaporator obtained an evaporation rate of 3.09 kg m −2 h −1 under one-sun illumination for seawater desalination. The PCM core within the microcapsules can store solar photothermal energy as latent heat under sufficient solar irradiation and then release it under evaporation conditions without sunlight illumination, thus enhancing the water evaporation efficiency. This enables the developed evaporator to increase its total evaporation mass by 31.5 % on a cloudy day in comparison with the conversional solar evaporator without a PCM, indicating a remarkable enhancement in the evaporation performance under intermittent solar irradiation. The developed solar interfacial evaporator exhibits great potential for application in sustainable solar-powered seawater desalination.
研究领域:
材料科学
·
环境工程
·
纳米技术
·
可再生能源
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Alimujiang Yalikun,Yanhong Wang,Yun Lv,Yaling Dou,Hyun-Joo Koo,Jiaojiao Cao,Wei Qi,Keke Huang,Myung-Hwan Whangbo,Zhongwen Ouyang,Hongcheng Lu
A series of analogous chain selenite chlorides Ba2M(SeO3)2Cl2 (M = Cu 1, Ni 2, Co 3, Mn 4) and Pb2Cu(SeO3)2Cl2 5 with tunable spin S from S = 1/2 to S = 5/2 have been hydrothermally synthesized and characterized. These analogues crystallized in the orthorhombic Pnnm space group (monoclinic P21/n space group for 5) all containing M2+–SeO3–M2+ spin chains, which are further separated by the Ba2+ ions (Pb2+ for 5). The magnetic susceptibility results of 1, 2, and 5 show broad maxima around 80.0, 18.9, and 78.0 K, respectively, indicating good one-dimensional (1D) magnetism. Meanwhile, no long-range order (LRO) is observed down to 2 K for both 1 and 5, while the isostructural compounds 2, 3, and 4 exhibit LRO at 3.4 K, 10.8 K, and 5.7 K, respectively, which are further confirmed by the heat capacity and electron spin resonance results, as well as the observed spin-flop transitions in the M–H curves measured at 2 K below TN. The magnetizations of 1–5 at 7 T are still far from saturation. In addition, thermal stability and FT-IR and UV–vis–NIR spectroscopy of 1–5 are reported.
研究领域:
无机化学
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材料科学
·
固体物理
·
磁学
·
晶体学
✓ 已验证
DOI
高影响因子
DESALINATION
·
2024
·
IF 8.3
Zhiheng Zheng,Huan Liu,Xiaodong Wang
A novel double-layered hydrogel based on the polyacrylamide matrix, pen ink, and phase-change microcapsules was developed to construct a hydrogel-based evaporator for efficient and continuous seawater desalination . The n -eicosane (core)@crystalline TiO 2 (shell) phase-change microcapsules were fabricated through interfacial polycondensation , and the resulting phase-change microcapsules obtained a considerably high latent-heat capacity of 187 J·g −1 . The upper layer of the hydrogel exhibits a high solar absorptivity of over 90 % due to the introduction of pen ink as a solar absorber, which helps the hydrogel-based evaporator to gain an excellent photothermal energy conversion capability. A high evaporation efficiency of 93.89 % was obtained for the developed hydrogel-based evaporator along with a high evaporation rate of 1.85 kg·m −2 ·h −1 under one-sun illumination. The phase-change microcapsules dispersed in the lower layer of the hydrogel can act as a latent heat-storage unit to store a great quantity of photothermal energy through melting phase change by the phase change material core. This imparts a consecutive evaporation capability to the developed hydrogel-based evaporator. As a result, its water production was increased by 11 % under 50-min one-sun illumination and 50-min non-illumination.
研究领域:
材料科学
·
环境工程
·
太阳能
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Huan Liu,Donglin Tian,Mize Ouyang,Zhiqiang Qian,Xiaodong Wang
Contamination and waste heat are major issues in water pollution. Aiming at efficient synchronous recovery wastewater and waste heat, we designed a novel CaCO 3 -based phase-change microcapsule system with an n -docosane core and a CaCO 3 /Fe 3 O 4 composite shell. The system was fabricated through an emulsion-templated in situ precipitation approach in a structure-directing mode, resulting in a controllable morphology for the resultant microcapsules, varying from a peanut hull through ellipsoid to dumbbell shapes. The system has a significantly enlarged specific surface area of approximately 55 m 2 ·g −1 with the CaCO 3 phase transition from vaterite to calcite. As a result, the microcapsule system exhibits improved adsorption capacities of 497.6 and 79.1 mg/g for Pb 2+ and Rhodamine B removal, respectively, from wastewater. Moreover, increase in the specific surface area of the microcapsule system with a sufficient latent heat capacity of approximately 130 J·g −1 also resulted in an enhanced heat energy-storage capability and thermal conductance for waste-heat recovery. The microcapsule system also exhibits a good leakage-prevention capability and good multicycle reusability owing to the tight magnetic CaCO 3 /Fe 3 O 4 composite shell. This study provides a promising approach for developing CaCO 3 -based phase-change microcapsules with enhanced thermal energy storage and adsorption capabilities for efficient synchronous recovery of wastewater and waste heat.
研究领域:
环境科学
·
材料科学
·
化学工程
·
可持续能源
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Tao Shi,Huan Liu,Xiaodong Wang
To realize highly efficient solar-thermo-electric energy conversion for clean electricity power generation, we have developed a new type of unidirectionally structured magnetic phase-change composite comprising a carbonized polyimide (C–PI)/Kevlar nanofiber (KNF) complex aerogel as a 3D carbon skeleton porous supporting material, CoFe2O4 nanoparticles as a magnetic additive, polyethylene glycol (PEG) as a phase-change material, and polypyrrole as a photothermal absorption coating layer. The as-fabricated C–PI/KNF complex aerogel exhibits a unidirectional microstructure, high porosity, robust skeleton frame, ultralight weight, and high thermal conductance. Featured with such unique structure and characteristics, the complex aerogel can offer an effective heat and electron transfer method to ensure highly efficient solar-thermal conversion and photothermal energy storage of the developed composite. The developed composite exhibits a high latent heat capacity of over 150 J g–1, outstanding shape stability along with a low leakage of 0.2 wt %, good thermal cycling stability, and high photothermal conversion efficiency of 84.8%. Based on the Seebeck effect, a solar thermoelectric generation system (STEGS) was constructed with the hot side coupled with the developed composite and the cold side immersed in air and ice water. Under 2.0 kW m–2 solar irradiation, the developed STEGS in ice water obtained maximum output voltage and current of 259.7 mV and 27.1 mA, respectively, which are significantly higher than those in air. The output power of the developed STEGS in an ice water environment is 50.6% higher than that in air under 4.0 kW m–2 solar irradiation. More importantly, the developed STEGS in ice water continuously generated output voltage and current for about 810 s without solar irradiation thanks to the latent heat release by the PEG component within the developed composite. In addition, the introduction of magnetic CoFe2O4 can accelerate solar-thermal conversion through periodic electron motion by the Néel relaxation or Brownian relaxation. This resulted in an increase in the maximum output voltage and current by 13.7 and 11.5%, respectively, under an alternating magnetic field as a result of the magnetism-accelerated solar-thermo-electric conversion. This study offers an innovative approach for developing PCM-based advanced functional materials for solar energy utilization in clean and sustainable electricity generation.
研究领域:
材料科学
·
能源工程
·
纳米技术
·
太阳能
·
热电学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY AND BUILDINGS
·
2021
·
IF 5.879
Xiaoyun Zhu,Xinxin Sheng,Jun Li,Ying Chen
Novel heat-storage composite coatings containing microencapsulated phase change material (MPCM) are prepared to enhance the thermal energy storage of the inner walls of an indoor environment. MPCMs with n-octadecane as core and polyurea as shell are synthesized via interface polymerization. They, along with the coatings, are characterized using Fourier transform infrared spectra (FTIR), SEM, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The SEM results show that MPCM can maintain its original morphology and be dispersed uniformly in the coatings with 30 wt% MPCM loads. Moreover, the latent heat capacity of MPCM and the heat-storage coatings are 151.89 J/g and 45.5 J/g, respectively. Other properties, such as thermal stability, temperature time lag, and film-forming are also tested, and the test results indicate excellent performances. After 200 heating-cooling cycles, MPCM and the heat-storage coatings still exhibit good thermal stability. Two reduced-scale test chambers enveloped by wall boards painted with and without MPCM coatings are tested under the same conditions and compared. Overall, the chamber with MPCM coatings can keep a stable temperature of 26-28 °C for approximately 77 min when the heating load is 80 W/m 2 . However, the chamber without PCM coating can only maintain such temperature for 13 min. Thus, the heat-storage coatings can improve the thermal comfort of indoor environments and have a high potential application in building thermal energy storage, especially for old buildings retrofit.
研究领域:
材料科学
·
能源工程
·
建筑科学
·
热物理学
✓ 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）