Sustainable Cities and Society
·
2018
·
IF 3.073
Li Yang,Xiaoling Cao,Nan Zhang,Bo Xiang,Zhaoli Zhang,Bin Qian
The thermal reliability of phase change materials (PCMs) is an important factor for the successful application of latent heat thermal energy storage. In this work, 10,000 thermal cycles have been firstly carried out to investigate the thermal reliability of four typical fatty acids (lauric acid, myristic acid, palmitic acid and stearic acid) as PCMs. The thermal properties before and after cycles were tested by differential scanning calorimeter. It was found that with increasing number of thermal cycles, both the phase transition temperature and the latent heat tended to decrease. In the experiment, the maximum change in the melting temperature was −0.37 °C and change rate of latent heat was −7.57%. The freezing temperature decreased obviously with increasing number of thermal cycles, which led to a maximum increase of 4.15 °C in the degree of supercooling. In addition, the specific heat and thermal conductivity of the PCMs after 10,000 thermal cycles had no significant change. FT-IR showed that the chemical structure of fatty acids had not changed after thermal cycles. The experimental results showed that these fatty acids can function as admirable PCMs with high thermal reliability for long-term applications.
研究领域:
材料科学
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热能工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2023
·
IF 5.7
Fengyi WANG,Ziwen LV,Linxiao Sun,Hongtao CHEN,Mingyu LI
Background In the field of electronic packaging, Sn-58Bi solder paste is a promising low-temperature option for step soldering. However, the tendency for the Bi-rich phase to coarsen and segregate poses a significant challenge to the long-term reliability of the solder joints. Methods The Sn coated Zn (Zn@Sn) core-shell particles were prepared through a chemical plating process and incorporated into the Sn-58Bi low-temperature solder paste to enhance its reliability. The microstructural and mechanical characteristics of the solder joints were evaluated under thermal cycling and thermomigration conditions to assess their long-term service reliability. Significant findings The addition of Zn lowers the nucleation energy and promotes the refinement of the eutectic structure, avoiding a significant reduction in shear strength after thermal cycling. In thermomigration, the heat transfer Q* of Bi is calculated to be 22.5 kJ/mol. The Zn-rich phases hardly move and are evenly distributed within the solder joints, acting like a barrier to prevent the Bi phase diffusing from the hot end to the cold end.
研究领域:
材料科学
·
电子封装技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Longkui Zheng,Yang Xiang,Dawei Zheng,Ning Luo
In this study, we systematically investigate the triboelectric performance degradation of polytetrafluoroethylene (PTFE)-based triboelectric nanogenerators (TENGs) under high–low temperature cycling and humidity variations, a critical yet underexplored challenge in extreme environmental applications. Under accelerated aging conditions spanning 0–300 thermal cycles and 0–90% RH, PTFE films demonstrated progressively worsening electrical output, their short-circuit current declining steadily from 7.2 to 4.6 μA, alongside an open-circuit voltage drop from 400 to 240 V. Surface characterization via scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy reveals that thermal cycling induces microstructural defects and chemical oxidation, where oxygen content replaced C–F bonds with weaker electron-accepting groups (C–O, C═O). This oxidative degradation reduced PTFE’s electron affinity and directly impaired charge transfer efficiency in TENGs. To address performance unpredictability, an improved extreme learning machine algorithm is developed, achieving 100% accuracy in real-time classification of PTFE aging states by analyzing triboelectric signals. Furthermore, paired with pristine PTFE, aged PTFE modified surface states enable a 21.8-fold power output enhancement and outperform conventional configurations. These findings establish a mechanistic framework linking thermal-humidity aging to triboelectric decay while proposing machine-learning-driven predictive maintenance strategies for TENGs in aerospace, energy systems, and autonomous devices operating in harsh environments.
研究领域:
材料科学
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纳米技术
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电气工程
·
表面科学
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机器学习
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环境测试
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高分子科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Energy Storage
·
2025
·
IF 9.8
Cheng Liu,Yi Zhang,Pengrui Zhang,Yigang Ding,Jinhe Sun
A multitude of composite phase change materials (PCM) systems have been developed, resulting in significant advancements in the efficiency of solar thermal storage systems. However, there is a paucity of inorganic-organic composite PCMs systems, and the phase change mechanism remains unclear, which significantly constrains the deployment and advancement of this category of PCMs. To address this gap in the literature, this team has developed a novel organic-inorganic composite PCM system using 30 wt% Mg(NO 3 ) 2 ·6H 2 O (MNH) and 70 wt% propanamide (POA) as raw materials. The thermal physical properties of the PCMs were initially analyzed, and the results demonstrated that the PCMs exhibited favourable latent heat and thermal cycling stability. The melting point was found to be 376.2 K, with a latent heat of melting of 131.93 J·g −1 . It was observed that the melting temperature and latent heat remained essentially unaltered after 500 cycles. Subsequently, the structure of the PCMs was analyzed using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Ultimately, the interaction between liquid MNH and POA was modeled using molecular dynamics, allowing for a deeper understanding of the phase transition mechanism. It is hypothesized that the hydrogen bonds (HBs) between the two substances affects the physical bond, and that HBs contribute to the PCMs having good stability and a high thermal decomposition temperature. The rational mechanism of this phenomenon is explained from many aspects, including structure, Hirshfeld surface and thermal analysis. It is anticipated that the discovery of this new PCMs will facilitate large-scale applications in solar energy storage.
研究领域:
材料科学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2025
·
IF 9.8
Cheng Liu,Yigang Ding,Jinhe Sun
Compared with single phase change materials (PCMs), organic-inorganic composite PCMs exhibits superior properties. Such as enhanced chemical stability, maintaining high energy storage density during thermal cycles. In this paper, a novel inorganic-organic composite PCM is synthesized with lithium nitrate (LNH) and acetamide (AC), which thermophysical properties are investigated systematically. The impact of α-Al 2 O 3 , β-Al 2 O 3 , expanded vermiculite, expanded graphite, boron nitride and bentonite on the energy storage density and cycle stability of composite PCM is examined intensively. The energy storage density of the composite PCM augmented with 1 wt% bentonite exhibits an increase rather than a decrease. After 100 cycles, a comparison of the data reveals that the average melting enthalpy of the PCM with bentonite (149.2 J·g −1 ) is 14.1 % higher than that without bentonite (124.2 J·g −1 ). The average enthalpy of solidification (150.8 J·g −1 ) is 21.4 % higher than that (130.7 J·g −1 ). Furthermore, the fluctuation range of the melting point and the freezing point is significantly reduced from 381.6 K–402.8 K and 313.8 K–402.2 K to 402.5 K–404.3 K and 393.8 K–403.9 K, respectively. The deviation of the melting temperature and latent heat after 100 cycles is <0.2 % in comparison to the initial value. The heat storage and release process of composite PCM in macro quantity is studied by step cooling curve test and computational fluid dynamics numerical simulation. It is confirmed that the LNH-AC/bentonite composite PCM not only has excellent long-term cycle stability, but also has no supercooling. LNH-AC/bentonite system is one of excellent candidates for solar heat storage.
研究领域:
材料科学
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热能工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yichao Gong,Jiarui Li,Lin Liu,Zhaokun Li,Longchao Zhuo,Guojun Zhang
Multiphase composites of lithium ceramics have emerged as a prominent area of research in the development of advanced solid tritium breeding materials. In this study, Li 2 TiO 3 /Li 2 SiO 3 co-doped Li 4 SiO 4 ceramic pebbles were prepared through an in-situ reaction between Li 4 SiO 4 and TiO 2 . The objective of this study is to enhance the thermal cycling stability of Li 4 SiO 4 by impeding the grain boundary migration of Li 4 SiO 4 under high temperature conditions. The effects of the in-situ generated Li 2 TiO 3 /Li 2 SiO 3 particles on the microstructure, crush load and thermal cycling stability of Li 4 SiO 4 ceramic pebbles were investigated. The in-situ formed Li 2 TiO 3 and Li 2 SiO 3 particles effectively hindered the grain growth and minimized the formation of large intracrystalline pores in Li 4 SiO 4 . At a sintering temperature of 900 °C, the Li 2 TiO 3 /Li 2 SiO 3 particles are beneficial in increasing the crush load of Li 4 SiO 4 ceramic. However, at lower sintering temperatures, their impact was counterproductive. An increase in the volume fractions of the Li 2 TiO 3 /Li 2 SiO 3 had a positive effect on grain refinement but a negative effect on crush load. The Li 2 TiO 3 /Li 2 SiO 3 co-doped Li 4 SiO 4 ceramic pebbles exhibited excellent structural stability during thermal cycling. The optimum mechanical stability was achieved at a TiO 2 addition of y = 0.1. The in-situ generated fine second phase particles effectively impeded grain boundary migration at high temperatures, providing a viable strategy for improving the thermal stability of Li 4 SiO 4 tritium breeders.
研究领域:
材料科学
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核能工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 3
·914
·
IF 3.748
Jintao Wang,Xinjie Wang,Lin Zhang,Luobin Zhang,Fangcheng Duan,Fengyi Wang,Weiwei Zhang,Jianqiang Wang,Zheng Zhang,Chunjin Hang,Hongtao Chen
A 3–5 μm Cu@Sn core-shell powder was prepared by chemical plating. Based on the mixture of this Cu@Sn and Ag NPs (nanoparticles), a soldering material for third-generation semiconductors was prepared. The joints prepared with this soldering material had a shear strength of over 40 MPa at 25 °C. This joint did not fail after more than 600 thermal cycles from −40 °C to 140 °C. The special feature of this joint is that the energy potential difference between nanoparticles and micron particles generated in the surface force field during reflow promoted the surface pre-melting of the particles by releasing the excess energy. By this mechanism, it was possible to reduce the porosity of the sintered layer. At the same time, due to the high surface activity energy of nano-silver, the diffusion of the Sn atoms was promoted, further enhancing the bond strength.Keywords:TLP;Cu@Sn;integrated packaging;soldering
研究领域:
材料科学
·
电子封装技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMPOSITE STRUCTURES
·
2024
·
IF 6.3
Zheng Sun,Quan-Xiu Liu,Feng Liu,Yuan-Qing Li,Fang-Liang Guo,Shao-Yun Fu
The reliability of short fiber reinforced polymer composites is crucial for their successful applications in aerospace engineering with cryo-thermal cycling (CTC). This study investigates the influences of CTC on the tensile properties of short carbon fiber (SCF)/polyetherimide (PEI) composites at room temperature (25 °C) and elevated temperature (170 °C). First, SCF surfaces were coated by carbon nanotube-polydomaine (CNT-PDA) hybrid sizing, and then SCF/PEI composites were prepared via the facile injection molding technique. Impressively and unexpectedly, the tensile strength at 25 °C and 170 °C of SCF/PEI composites is all enhanced by the CTC exposure, attributing to the enhanced mechanical properties of PEI matrix and fiber/PEI interface bonding. In addition, CNT-PDA sizing and CTC exposure have a combined effect on improving the tensile properties of SCF/PEI composites at 25 °C and 170 °C. Overall, the SCF/PEI composites exhibit excellent mechanical properties under extreme service conditions, and are thus promising to serve in aerospace components.
研究领域:
航空航天工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2024
·
IF 13
Kaichen Wang,Keyu Tao,Feng Ye,Tieying Wang,Chao Xu
Addressing critical issues such as high-temperature corrosion, leakage, degradation, and subpar cyclic performance is imperative for phase change materials (PCMs), prompting the development of appropriate encapsulation techniques to surmount these challenges. In this study, a dual encapsulation strategy is proposed for high-temperature micro PCM particles. Al–Si core is microencapsulated via the “solvent evaporation-heating curing” method. Subsequently, TiO 2 is employed as the skeleton material for form-stable encapsulation of PCM microcapsules by “cold pressed sintering”. Detailed analysis of the crystalline phase transformation mechanism in the sintering synthesis pathway of TiO 2 underscore its potential as a robust structural material with exceptional thermal stability. Furthermore, the incorporation of hexagonal boron nitride (hBN) results in a substantial enhancement of the thermal conductivity of the composites, increasing by 121.1–131.3%. The prepared form-stable phase change microcapsules (FSPCMs) are subjected to 5000 thermal cycles in the air atmosphere. There is no observed PCM leakage or composite ruptures in the FSPCM. Moreover, the oxidized mass gain is merely 3.3%, signifying exceptional oxidation resistance. Thermophysical analysis indicates that FSPCM can retain 91.3% of the enthalpy after 2000 cycles, with over 80% preservation after 5000 cycles, underscoring its remarkable cyclic thermal durability.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2019
·Vol. 138
·期 1
·233-241
·
IF 2.471
Wei Sheng,Duan Zhijun,Xia Yongpeng,Huang Chaowei,Ji Rong,Zhang Huanzhi,Xu Fen,Sun Lixian,Sun Yixin
High-performance phase change materials (PCMs) are regarded as a promising strategy in thermal energy storage applications. However, pure PCMs exhibit some inherent disadvantages such as leakage, low thermal conductivity and poor thermal cycling stability. Herein, this work presents novel microencapsulated PCMs with nano-Al 2 O 3 -enhanced shell materials due to the high thermal conductivity and mechanical properties of nano-Al 2 O 3 . And nano-Al 2 O 3 was contributed uniformly to the shell materials through self-assembly of functional materials, forming a connected thermal conductive network for the microencapsulated PCMs and resulting in an enhancement on the thermal conductivity of the microencapsulated PCMs. Results show that thermal conductivity of the obtained microencapsulated PCMs with 8 mass% nano-Al 2 O 3 is improved up to 0.5977 W m −1 k −1 which is about 287.4% compared with that of the pure PCMs. Moreover, the obtained microcapsules enhanced by nano-Al 2 O 3 possess good phase change behavior and excellent thermal cycling stability, whose melting enthalpy can achieve 170.5 J g −1 and almost has no change after 12 times of thermal cycles.
研究领域:
材料科学
·
热能储存技术
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2014
·
IF 2.105
Yanhong Ma,Shiding Sun,Jianguo Li,Guoyi Tang
Using suspension-like polymerization method, a series of microencapsulated phase change materials (micro-PCMs) with acrylate-based polymer shells and binary core materials were prepared. The phase change properties of the binary mixtures composed of paraffin and butyl stearate were investigated. SEM photographs showed that these micro-PCMs have relatively spherical profiles and compact surfaces with diameter ranging from 10 to 80 μm. DSC results indicated that the microencapsulation ratio of these micro-PCMs ranging from 46 wt% to 68 wt%. Moreover, after being subjected to thermal-cycling test for 500 times, these micro-PCMs kept good thermal reliabilities that the microencapsulation ratio decreased by less than 4 wt%. TGA analysis demonstrated that these micro-PCMs can ensure their thermal stability below 210 °C.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2022
·
IF 6.206
Weiwei Li,Chunyang Wei,Jiyun Tang,Zongkui Li,Xiaowei An,Qi Li,Jingjing Wang,Liwei Liu
Long-term protection in highly corrosive environments has advanced to use high-solid coatings with high thickness, known as high-build coatings. However, these coatings were found to be more susceptible to cracking and delamination failures in-service with temperature variations. To understand how a high-build film is stressed at different temperatures, we developed an efficient measurement method by employing imaging scanning device and image analysis to quantitatively evaluate internal stress in two purposely formulated epoxy coatings with different elasticities through 30 thermal cycles between −25 to 50 °C. The results showed that the magnitude of internal stress was dependent on the coating elasticity, film thickness, and the difference in coefficient of linear thermal expansion (CTE) between the coating and its substrate apart from the service temperature and the thermal cycles. Moreover, thicker coating develops a significantly higher internal stress, which explains why cracking or delamination is typically associated with excessively thick coatings. The investigated mechanisms of the stress development during thermal cycling will be a useful guide to formulate mechanically durable high-build coatings.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）