Energies
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2019
·Vol. 12
·期 18
·3406
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IF 2.707
Weiguang Su,Yilin Li,Tongyu Zhou,Jo Darkwa,Georgios Kokogiannakis,Zhao Li
Previous research has demonstred that microencapsulated phase change materials (MEPCMs) could significantly increase the energy storage density of solar thermal energy storage (TES) systems. Compared with traditional phase change materials (PCMs), MEPCMs have many advantages since they can limit their exposure to the surrounding environment, enlarge the heat transfer area, and maintain the volume as the phase change occurs. In this study, a new MEPCM for solar TES systems is developed by encapsulation of paraffin wax with poly (urea formaldehyde) (PUF). The experimental results revealed that agglomeration of MEPCM particles occurred during the encapsulation process which affected the uniformity of the particle size distribution profile when sodium dodecyl sulfate was used as an emulsifier. The differential scanning calorimetric (DSC) analysis results showed that the melting temperatures were slightly increased by 0.14–0.72 °C after encapsulation. A thermogravimetric (TG) test showed that the sample weight decreased while the weight loss starting temperature was slightly increased after encapsulation. Overall, the sample UF-2, fabricated with the binary emulsifiers of Brij 35 and Brij 30 and 5% nucleating agent, resulted in good particle dispersion and shell integrity, higher core material content and encapsulation efficiency, as well as improved thermal stability.Keywords:solar energy;thermal energy storage;microencapsulation;phase change material;poly (urea formaldehyde)
研究领域:
能源科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
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2021
·
IF 9.078
Zixuan Niu,Shengyang Qi,Suhaib Shuaib Adam Shuaib,Weizhong Yuan
Smart textiles have emerged as potential part for wearable devices and protective systems. Integrating phase change materials (PCMs) into stimuli-responsive fibers offers exciting opportunities for smart clothing to realize instant energy conversion/storage and temperature regulation. However, the production of flexible and efficient smart energy storage fiber is still challenging. Here, flexible electro-/photo-driven energy storage polymer fiber with outstanding hydrophobicity and self-cleaning property is fabricated. The smart fiber is prepared by integrating conductive silver nanoflowers and poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) as well as hydrophobic fluorocarbon resin with a facile and novel wet-spun phase change fiber to gain high flexibility, excellent electrical conductivity , high enthalpy, tunable phase change temperature , extra shape stability and outstanding hydrophobicity. The highest elongation of the smart fiber is more than 500% and the enthalpies of the fibers varies from 98.6 to 124.5 J g −1 according to the adjustable content of phase change materials. The coordination of Ag nanoflowers and PEDOT:PSS enable the fiber outstanding electrical conductivity of 190 S/m 2 . The high electrical conductivity, excellent photo capture and good heat dissipation enable the fiber high electro-/photo-heat conversion efficiency (70.1% and 89.0%, respectively). The smart energy storage fiber with integrative properties could be woven into fabrics, providing a new option for smart textiles in wearable and protective systems.
研究领域:
纺织科学
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材料科学
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能源技术
✓ 已验证
产品关联
DOI
高影响因子
Progress in Natural Science-Materials International
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2021
·
IF 3.607
Pan Zhang,Zefeng Cheng,Zhang Chen,Yanfeng Gao
Liquid-solid phase change materials (PCMs) show reversible storage and release of latent heat, which has attracted extensive interests in applications for thermal energy storage. However, stubborn leakage issue may cause corrosion and extra thermal resistance. The non-wettability of melted paraffin on the oleophobic surface of diatomite has been reported by authors earlier, and the result showed that the encapsulation ratio (84.5%) of diatomite@paraffin shape-stabilized PCM greatly increased. Here, in order to prove this method equally applicable to other PCMs and porous natural clay minerals, diatomite and sepiolite were oleophobically modified to encapsulate melted stearic acid and paraffin, to form shape-stabilized PCMs. The results showed that the encapsulation ratios of 67.8% and 56.6% for diatomite@stearic acid and sepiolite@paraffin were higher than that reported in the references (28.9% and 36.8%). In addition, the encapsulation ratios of diatomite-based shape-stabilized PCMs can be also increased using different PCMs, such as n -octadecane and polyethylene glycol via the same approach. Therefore, this is a universal method for improving encapsulation ratios of shape-stabilized PCMs.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Xiaosheng Du,Linzhao Jin,Sha Deng,Mi Zhou,Zongliang Du,Xu Cheng,Haibo Wang
Conventional polymeric phase change materials (PCMs) exhibit good shape stability, large energy storage density, and satisfactory chemical stability, but they cannot be recycled and self-healed due to their permanent cross-linking structure. Additionally, the high flammability of organic PCMs seriously restricts their applications for thermal energy storage (TES). Therefore, it is urgently required to explore PCM composites exhibiting superior recyclability, good self-healing capability, and excellent flame retardancy simultaneously. Herein, tri-maleimide end-capped cyclotriphosphazene flame retardant (TMCTP) was synthesized via the nucleophilic substitution between 1,3,5,2,4,6-triazatriphosphorine-2,2,4,4,6,6-hexachloride and N-(2-hydroxyethyl)maleimide. Then, novel dynamically cross-linked PCM composites (FPCMs) with superior recyclability, good self-healing capability, and excellent flame retardancy were fabricated by bonding PEG and TMCTP to polymeric skeleton via reversible furan/maleimide Diels–Alder (DA) reaction. TMCTP, which covalently and dynamically binding in the polymeric FPCMs, acted not only as an efficient flame retardant for reducing the flammability of PCM composites but also as dynamic cross-linking skeletons for thermally induced self-healing and recycling. Differential scanning calorimetry (DSC) analysis confirmed the reversible energy storage and release ability of FPCMs. Due to its reversible DA covalent bonds, the introduction of TMCTP endowed the FPCMs with considerably increased self-healing efficiency (up to 93.1%) and recyclability efficiency (94.6%). Moreover, with the introduction of TMCTP into FPCMs, the heat release rate (HRR) and total heat release (THR) significantly decreased, while the char residue and limiting oxygen index (LOI) value increased, confirming that the flame retardancy of FPCMs greatly improved. Hence, the synthesized FPCMs show enormous potential in TES applications.
研究领域:
材料科学
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能源工程
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2022
·
IF 6.633
Wenjie Sun,Qingyi Liu,Jiateng Zhao,Hafiz Muhammad Ali,Zafar Said,Changhui Liu
With the development of electronic machinery, the traditional heat exchange working fluid can no longer be used in some extreme working environments. As a new type of fluid, deep eutectic solvent has the advantages of promising thermal stability, low cost and non-toxicity through the hydrogen bond association of hydrogen bond acceptor and hydrogen bond donor, and is also coined to be an efficient heat transfer working fluid. In this work, three kinds of nanofluids filled with TiO 2 , Al 2 O 3 and Fe 2 O 3 nanoparticles were prepared with glycerol/sodium acetate trihydrate deep eutectic solvent as the base solution, and the mechanism of thermal conductivity change of nanofluids were discussed from atomic and microscopic levels. The experimental results showed that the prepared glycerol/ sodium acetate trihydrate 2:1 deep eutectic solvent system reduced the viscosity by 58.03% compared with glycerol, and increased the thermal conductivity by 17.2% compared with glycerol at 25 ℃. The effects of nanoparticles on thermal conductivity and specific heat capacity were also investigated. Compared with deep eutectic solvent, the thermal conductivity was improved after adding Fe 2 O 3 nanoparticles; it is worth noting that the specific heat capacity of nanofluids was more than doubled after adding nanoparticles.
研究领域:
材料科学
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热力学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY
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2023
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IF 6.7
Mengting Ji,Laiquan Lv,Jingwen Liu,Yan Rong,Hao Zhou
The coefficient of thermal expansion of inorganic salts increases with increasing temperature. The sintering temperature may affect the properties of the shape-stable phase change materials (SSPCMs). We study the SSPCMs with NaNO 3 -KNO 3 as the phase change material and Al 2 O 3 and expanded graphite (EG) as the skeletal support materials (SSMs) to achieve thermal energy storage over a wide temperature range. The effects of different sintering temperatures on the SSMs content, thermal conductivity and compressive strength of SSPCMs were studied. The results showed that as the sintering temperature increased, more SSMs were required to support the SSPCMs. The maximum NaNO 3 -KNO 3 mass percentages of the SSPCMs sintered at 300 °C and 450 °C were 82.8 wt% and 66.4 wt%, respectively. Samples with application temperatures higher than the sintering temperature may have problems stabilizing the shape. Sintering temperature had little influence on the thermal conductivity of the same SSPCMs. However, the compressive strength of the SSPCMs decreased with increasing sintering temperature. The addition of EG decreases the decomposition temperature of the composite and limits its application temperature range. The SSPCM-10/30 sintered at 450 ℃ showed good chemical stability performance, and the latent heat decreased from 56.01 J/g to 53.44 J/g. The compressive strength dropped from 30.7 MPa to 25.17 MPa before and after 20 cycles due to larger internal gaps and did not change much after 20 cycles.
研究领域:
材料科学
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能源工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2018
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IF 6.735
Qinrong Sun,Haiquan Zhang,Jiajia Xue,Xiaoping Yu,Yanping Yuan,Xiaoling Cao
Flexible phase-change materials (PCMs) have great potential applicability in thermal energy storage and temperature control. A binary composite mixture comprising polyethylene glycols of solid and liquid phases (PEG2000 and PEG400, respectively) was synthesized as a PCM base material. The PEG400 liquid phase was uniformly dispersed in the PEG2000 phase-change crystal on a molecular scale, thus creating many micro- and nanocrystals of PEG2000 via polycrystalline growth from a single crystal. To retain solidity and flexibility in the composite’s melted state, hydrogel technology and low-temperature drying were applied. We prepared flexible polymer gel shaped PCMs by adding sodium stearate (NaR) to the binary fused mixture. Needle-shaped NaR crystal grains of several hundred nanometers formed three-dimensional network structures, binding the binary flexible PCM within the network structure to form a polymer gel. These geometric structures not only achieve the solid–liquid PCM structure but also maintain flexibility in both the melted and solidified states (20–80 °C). The latent heats of melting and solidification for the polymer gel were 109.7 and 107.2 J/g, accounting for 87.5% and 85.8% of the PP20 binary eutectic, respectively. The demonstrated use of polymer gels provides a new route for investigating PCMs for heat storage.
研究领域:
材料科学
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能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF CLUSTER SCIENCE
·
2022
·Vol. 34
·期 1
·547-556
·
IF 3.447
Mo Songping,Shan Shaofei,He Lijuan,Jia Lisi,Chen Ying
Nanoencapsulation can effectively protect phase change material (PCM) from the ambient. Sugar alcohols have great potential for thermal energy storage. However, base or acid used in the most popular encapsulation methods may damage the PCM core. In this study, binary sugar alcohols of D-mannitol (DM) and inositol (IN) were first nanoencapsulated at neutral pH conditions. Nanocapsules with silica as the shell and different DM/IN ratios of 4.0:1, 4.6:1 and 5.5:1 were synthesized at different precursor ratios of tetraethoxysilane to triethoxysilane of 8:6, 9:5, and 10:4. The nanoencapsulation was demonstrated by scanning electron microscope (SEM), transmission electron microscope, energy-dispersive X-ray spectrometry, and Fourier transform infrared spectrometer. The phase change characteristics, thermal energy storage-release performance and thermal stability of the nanocapsules were studied by differential scanning calorimeter, thermal energy storage-release experiments, SEM, thermo-gravimetric analyzer (TGA) and thermal cycling tests. Results show that the phase change characteristics and thermal energy storage-release performance of the nanocapsules varied with the DM/IN mixing ratio and ratios of precursors. The DM/IN-4.6:1-9:5@SiO 2 nanocapsules exhibited the best phase change characteristics and thermal energy storage-release performance. Thermal stability of the nanocapsules was improved compared to pure binary sugar alcohols.
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
JOURNAL OF MOLECULAR LIQUIDS
·
2025
·
IF 5.2
Yue Zhang,Jinli Li,Yaya Jia,Linzhe Wang,Kang Wu,Shan Liu,Bing Liu
Solar salt (SS), serving as both a thermal energy storage (TES) material and heat transfer fluid (HTF), plays a critical role in determining the overall efficiency of concentrating solar power (CSP) plants through its thermophysical properties. Thus, a high-temperature static melting method and ultrasonic aqueous solution method was used to prepare nano CuO-SS nanocomposites for investigating the thermal properties improvement of SS by two different particle sizes of nano CuO (40 nm and 100 nm). The liquid specific heat capacity (c p ) appeared a trend of first increasing and then decreasing with the addition of nano CuO. It was 1.99 J/(g·K) and 1.81 J/(g·K) when the two nano CuO content was both 1.5 wt% in two system, and there was an increase of 28.39 % (nanocomposite CuO1-SS-4 of CuO1-SS system, Cu1SS-4) and 16.77 % (nanocomposite of CuO2-SS system, Cu2SS-4) compared with the pure SS respectively. The nanocomposites Cu1SS-4/Cu2SS-4 maintained excellent thermal stability, showing no change in their working temperature range compared to pure SS. The uniform dispersion of nano CuO particles was confirmed through scanning electron microscopy (SEM) characterization. The superior heat storage capacity results from the greater surface area and higher surface energy of smaller nano CuO, which facilitated more efficient thermal energy storage in the system. It had increasement of 47.25 % and 56.04 % about thermal conductivity of nanocomposite Cu1SS-4 and Cu2SS-4. The nitrate-based nanocomposite as a promising candidate material for thermal energy storage, due to its high heat storage, excellent chemical compatibility, large suitable working temperature and high thermal stability.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Ting Wang,Wei Cui,Xiangxuan Li,Ting Ma,Qiuwang Wang
Due to their high heat storage density, low cost, and non-inflammability, hydrated salts have significant potential for application in thermal energy storage for buildings. Hydrated salts, however, have a few drawbacks, including high supercooling degree, unstable shape, and phase separation. In general, materials such as graphite, aerogel, and foam metal are commonly used to provide support for hydrated salts in order to mitigate or eliminate their drawbacks. While these currently used supporting materials have expensive and complicated production procedures. In this study, we developed bagasse biomass-derived carbon (BBC) materials to obtain easily accessible, cost-effective, and environmentally friendly support materials. Using the high-temperature carbonization method, the bagasse made from biological waste displayed a highly oriented and stacked lamellar structure. This not only significantly lowered the cost but also made the storage of hydrated salts easier. A straightforward vacuum impregnation technique was used to create SSD-SC/BBC phase change composites (PCCs). In comparison to sodium sulfate decahydrate (SSD), the developed SSD-SC/BBC9 PCCs exhibited a higher thermal storage capacity of 161.5 J/g, along with an exceptionally low supercooling degree. They also demonstrated the higher thermal conductivity of 1.79 W·m −1 ·K −1 , improved thermal reliability, and enhanced solar-thermal energy conversion ability. Compared to other support materials, the economic analysis using static and dynamic payback periods demonstrates that the utilization of biomass-derived carbon as a support material for phase change materials (PCMs) is cost-effective, with lower preparation costs and a shorter payback period. A simple, affordable, and environmentally friendly method for utilizing hydrated salts in thermal energy storage for buildings is provided by SSD-SC/BBC9 PCCs.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Refrigeration
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2024
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IF 3.5
Songping Mo,Junhao Chen,Yuxin Yu,Yufen Chen,Lisi Jia,Ying Chen
Using ethylene glycol solution as the base fluid has demonstrated its effectiveness in reducing the freezing point of the continuous phase in phase change emulsions. This, in turn, enhances the stability of the emulsion at low temperatures, which has significant implications for applications requiring emulsions in such conditions. However, there is a notable absence of comprehensive studies on this topic. In this study, we utilized the phase conversion method to prepare hexadecane emulsions with varying mass fractions, using ethylene glycol aqueous solution as the base fluid. The impact of the ratio of hexadecane to surfactant and the formulation of the surfactants on the dispersion stability of the emulsions were systematically investigated and optimized. Furthermore, the phase change and thermal properties of the emulsions were examined. Based on these results, the energy storage capacity and pumping power of the emulsions were calculated and compared with those of the base fluid. The results indicate that as the mass fraction of phase change material (PCM) increases, the energy storage capacity and viscosity of the emulsions also increase, while the thermal conductivity decreases. Additionally, the energy storage capacities of the emulsions surpass that of the base fluid, and the pumping power is reduced at relatively low PCM mass fractions and within the heat storage temperature range. The appropriate mass fraction of PCM were determined by comparing these outcomes.
研究领域:
能源科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY AND BUILDINGS
·
2024
·
IF 6.6
Xuemei Zhang,Jianjuan Yuan,Yue Han,Xiangfei Kong
The huge heat loss/gain through windows is the reason for a large amount of energy consumption in buildings. Although using the heat storage capacity of phase change material (PCM) to improve the thermal inertia of windows is an important way to reduce energy consumption, leakage and overheating at noon limit the development of windows containing solid–liquid PCM. Smart windows based on temperature-sensitive hydrogel have aroused great interest due to their excellent ability to dynamically control solar energy. However, current temperature-sensitive hydrogels with single transition temperature and uncontrollable transition speed affect indoor light comfort. Meanwhile, the low heat storage performance of hydrogels limited their energy-saving effect. Therefore, a novel smart window (P3H6) integrating temperature sensitivity and energy storage was constructed by the prepared hydrogel and form-stable PCM. The double-network hydrogel with adjustable temperature band and mechanical enhancement was constructed by acrylamide and N-isopropylacrylamide, which realized the dynamic adjustment of solar energy. The prepared form-stable PCM avoided the leakage problem and improved the heat storage capacity of the window. The comprehensive transmittance of P3H6 can be changed between 3.3 %-62.7 %-2.6 % in a day, which blocked the sunlight from transmitting heat at noon and protected privacy at night. The outdoor experiments showed that P3H6 delayed the inner surface temperature of the window to 32 °C by 1.05 h compared with traditional windows, which reduced the thermal radiation of windows to the room and improved the thermal comfort of indoor personnel. More importantly, the application of P3H6 can reduce the daytime cooling load of buildings by 28.84 %. To sum up, the proposed smart window shows great potential in energy-saving buildings.
研究领域:
材料科学
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能源工程
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建筑技术
✓ 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）