Journal of Energy Storage
·
2024
·
IF 8.9
Zijian He,Hongting Ma,Shilei Lu
In order to effectively address the mismatch between thermal energy supply and demand in buildings, latent heat storage (LHS) based on phase change material (PCM) stands out as a key technology. While hydrated salt has emerged as a promising PCM, it encounters common issues such as substantial supercooling, phase separation, and low thermal conductivity , hindering its development. To mitigate these limitations, this study focused on modifying Ba(OH) 2 ·8H 2 O by incorporating various nucleating agents and thickening agents to reduce supercooling, enhancing the composite PCM's thermal properties by introducing expanded graphite (EG) to elevate thermal conductivity . Subsequently, the thermal stability of the PCM was evaluated through accelerated thermal cycling tests, encompassing the assessment of critical thermal parameters, including supercooling degree, enthalpy, and thermal conductivity of the composite PCM. Experimental findings unveiled the effectiveness of incorporating 2 wt% BaCl 2 ·2H 2 O and 1 wt% CMC to Ba(OH) 2 ·8H 2 O, effectively diminishing the supercooling degree from 14 °C to 1.42 °C. Further integration of 3.5 wt% EG led to a substantial decrease in the supercooling degree to 0.24 °C. Simultaneously, the addition of EG resulted in an improvement in thermal conductivity , elevating it from 0.62 W/(m·K) to 1.03 W/(m·K), while the enthalpy decreased from 283.68 J/g to 252.81 J/g. Notably, the composite PCM exhibited notable thermal reliability with a latent heat drop of 15.9 % following 1000 accelerated cycles of testing. Moreover, the composite PCM demonstrated superior thermal storage density, measuring at 2.36 times that of traditional paraffin wax , yet with a thermal storage cost merely a quarter of paraffin wax, rendering it more favorable for extensive deployment in building energy systems .
研究领域:
能源工程
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建筑材料
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2018
·
IF 0
Jotham Muthoka Munyalo,Xuelai Zhang,Xioafeng Xu
With increasing concerns over global warming, there is compelling need to apply energy technologies to improve energy efficiencies. One of the new technologies is the use of phase change materials (PCMs) to store energy and release it on demand. However, most of these materials undergo supercooling, aggregation and have low thermal conductivity that inhibits effective heat transfer. In this paper supercooling, stability, energy storage,thermal conductivity and latent heat of fusion of water based nanofluid of barium chloride dehydrate (BaCl 2 ·2H 2 O) were experimentally studied by adding a mass fraction of 0.2 w.t%–1 wt.% magnesium oxide (MgO) and 0.2 wt.%–1 wt.% multi-walled carbon nanotubes (MWCNTs). Results show that by adding separately mass fraction of 1.% of MgO and MWCNTs reduce the supercooling degree of barium chloride dehydrate by 85% and 92% respectively. At the same mass fraction, thermal conductivity also improves by 6% on addition of MWCNTs and 17% on addition of MgO. However, the enthalpies reduce by 7% at 1 wt.% MgO and by 12.3% at 1 wt% MWCNTs. It was found that MgO exhibited relatively higher thermal conductivity and a lower reduction in latent heats at a mass fraction of 1 wt.%. Surfactant was also found to prevent aggregation at low temperatures.
研究领域:
能源技术
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材料科学
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产品关联
DOI
Journal of Energy Storage
·
2023
·
IF 9.4
Chenzhen Liu,Qingjiang Cheng,Peixing Du,Xue Wang,Mingming Wu,Zhonghao Rao
Sugar alcohols phase change thermal energy storage materials have many advantages such as high latent heat, non-toxicity and abundance, which are extremely potential in the field of thermal energy storage. However, the application of sugar alcohols in thermal energy storage is greatly restricted by high supercooling. In this work, alumina porous ceramics (APC) were successfully prepared by replication template method , and then the prepared APC were modified by 3-aminopropyltriethoxysilane to obtain APC-SiX. The APC and APC-SiX were used to improve the thermal properties of erythritol (ET), d -mannitol (DMT) and d-dulcitol (DDT), respectively. Based on the results, the supercooling degree and solidification stability degree of sugar alcohols were suppressed observably, among which, the supercooling suppression for ET was the most significant. The supercooling degree and solidification stability degree of ET were suppressed to 3.3 ± 0.1 °C and 0.7 ± 0.2 °C, respectively. Besides, the thermal conductivity of the sugar alcohols was also obviously enhanced. Furthermore, the high latent heat, excellent cycling thermal stability and anti-leakage of sugar alcohols composite phase change materials (PCM) are also available. This conclusion is important for supercooling regulation and thermal property optimization of sugar alcohols, and indeed, can promote the utilization of sugar alcohols in thermal 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 COLLOID AND INTERFACE SCIENCE
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2024
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IF 9.4
Shuhua Liang,Xinyu Wang,Liheng Chen,Xueqing Qiu
Fatty acids, in particular, are valued as phase change materials (PCMs) for their non-toxic, biodegradable nature and thermal stability. However, the leakage and supercooling issues during phase transitions limit their application. Microencapsulation of PCMs, while improving thermal response, often leads to supercooling, complicating temperature regulation and increasing energy consumption. Lignin, a renewable biomass resource, offers potential as a shell material for PCM encapsulation. To address compatibility issues between lignin and fatty acids, we modified lignin via acetylation and prepared hybrid acetylated lignin-stearic acid capsules (hyb-ACLSCs) using an anti-solvent method. Density functional theory (DFT) revealed that acetylated lignin exhibits stronger interactions with fatty acids, leading to higher particle yields (40.8 %), enhanced fatty acid loading (57.2 %) with a high phase-transition temperature of about 70 ℃, and improved phase transition behavior with a stable latent heat of about 250 J/g after 50 heating–cooling cycles. The heterogeneity of lignin facilitated multi-hierarchical self-assembly, preventing supercooling and enabling the formation of nano-sized phase change materials. The resulting hybrid capsules demonstrated high latent heat, negligible supercooling, and are highly promising for energy storage applications.
研究领域:
材料科学
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能源工程
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生物质利用
✓ 已验证
产品关联
DOI
PubMed
高影响因子
International Journal of Extreme Manufacturing
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2025
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IF 21.3
Guofeng Liu,Pengcheng Xia,Weicheng Kong,Tianhong Qiao,Yuan Sun,Wenjie Ren,Yong He
3D printing of soft/tough hydrogels has been widely used in flexible electronics, regenerative medicine, and other fields. However, due to their loose crosslinking, strong hydration and plasticizing effect of solvent (typically water) and susceptibility to swelling, the printed hydrogels always suffer from bearing compressive stress and shear stress. Here we report a 3D photo-printable hard/soft switchable hydrogel composites which enabled by the phase transition (liquid/solid transition) of supercooled hydrated salt solution (solvents) within hydrogel. In hard status, it achieved a hardness of 86.5 Shore D (comparable to hard plastics), a compression strength of 81.7 MPa and Young's modulus of 1.2 GPa. These mechanical property parameters far exceed those of any currently 3D printed hydrogels. The most interesting thing is that the soft/hard states are easily switchable and this process can be repeated for many times. In supercooled state, the random arrangement of liquid solvent molecular within hydrogels makes it as soft as conventional hydrogels. Upon artificially seeding of crystal nucleus, the solvent in hydrogel undergoes rapid crystallization, resulting in the in-situ formation of numerous rigid, ordered rod-like nanoscale crystals uniformly embedded within the hydrogel matrix. This hierarchical structure remarkably enhances the Young's modulus from kPa to GPa. Furthermore, the softness of hydrogel can be restored by heating and then cooling down to recover the supercooled state of solvent. Taking the advantage of soft/hard status switching, the hydrogel can conform to complex surface morphologies in their soft and then frozen that shape through crystallization, enabling rapid mold fabrication. Moreover, a shape fixation and recyclable smart hydrogel medical plaster bandage was developed also, capable of conforming the limb shapes and providing adequate support for the bone fracture patients after 10 minutes of crystallization. Our work suggests a bright future for direct use of the hard hydrogel as a robust industrial material.
研究领域:
生物材料学
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医学工程
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 55
·期 7
·2994-3004
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IF 3.442
Ji Jun,Wang Yinghui,Zhang Xuelai,Chen Yue,Munyalo Jotham Muthoka,Liu Sheng
Supercooling of phase change materials (PCMs) during solidification is a major problem in cold thermal energy storage (CTES), which reduces energy efficiency and aggravates energy waste. This study focuses on the supercooling characteristics of PCMs under heterogeneous nucleation, which provides a new idea for researching the influence of different dispersants on the supercooling degree of aqueous solution. The optimal ratios of CNTs water dispersant (TNWDIS) and polymer polyacrylic acid sodium (PAAS) to multi-walled carbon nanotubes (MWCNTs) in mannitol aqueous solution are determined through microstructure and cooling characteristics. How these two surfactants and MWCNTs with different concentrations and particle sizes influence the supercooling degree of nanofluids are investigated. The results indicate that the effect of PAAS is greater than that of TNWDIS. Furthermore, under the action of two dispersants and particle sizes of MWCNTs, the fitting equations of supercooling changing with the concentration of MWCNTs are obtained. In the light of the heterogeneous nucleation theory, with the enlargement of the particle size and the diminution of the contact angle affected by the dispersants, the interfacial free energy of heterogeneous nucleation of PCMs on the surface of nanoparticles is reduced. The supercooling degree therefore decreases. Specifically, the nucleation mechanism is deduced and analyzed through the contact angle and nucleation free energy formula.
研究领域:
能源存储
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材料科学
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热力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF FOOD SCIENCE
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2023
·Vol. 88
·期 3
·977-987
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IF 3.9
Wenfu Hou,Yile Lin,Yujie Zhang,Tingting Liu,Juan Du,Yang Yi,Hongxun Wang
This study investigated the effect of 0.8% (m/v) kojic acid treatment on changes in the microstructure and myofibrillar protein of duck meat covered with oxygen-permeable polyvinylchloride (PVC) film (9 ± 0.5 µM) during superchilled storage (−1.65 ± 0.5°C). The superchilled samples exhibited wider gaps between muscle fibers at 5 weeks storage compared with kojic acid–treated groups. Based on the variation of water status, the water-holding capacity decreased significantly ( p < 0.05), and bound water and immobilized water were gradually converted into free water during superchilled storage. For kojic acid–treated samples, however, no major changes were observed with respect to muscle structure, water status, and protein degradation at 6 weeks. The 0.8% (m/v) kojic acid treatment increased the water-holding capacity, reduced carbonyl content and protein degradation, and decreased the α-helix contents loss of myofibrillar proteins. Kojic acid treatment effectively protected myofibrillar protein structure from being destroyed during superchilled storage, suggesting that this method was a good way to reduce protein oxidation and prolonged its shelf life.
研究领域:
食品科学
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生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
International Journal of Refrigeration
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2021
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IF 3.629
Chang Liu,Yanjun Chen,Chaocan Zhang
Cold energy storage technologies with phase change materials (PCMs) have received increasing attention, but there is still a great vacancy for PCMs that can be applied below 0°C due to high supercooling degree of aqueous solution. In this work, the nanosheet dispersion phase change materials (NDPCMs) containing the ethylene glycol (EG) aqueous solution and the modified montmorillonite (MTT) at different mass fractions were prepared, in which the modified MTT prepared by surface modification of zwitterionic surfactant and polymer quaternary ammonium salt under high speed shearing could be steadily dispersed due to the combination of charge and steric effects. And the modified MTT could be used as the nanosheet nucleating agent to effectively suppress the supercooling as well as improve the thermal properties of the PCM. The NDPCM with 0.4 wt% modified MTT had an appropriate phase transition temperature of -5.0°C, higher latent heat of fusion of 189.96 kJ•kg −1 , and there was no supercooling in the test of step cooling curves. Moreover, the NDPCM still showed excellent dispersion stability after 50 thermal cycles. These results indicate that the NDPCM has practical application value in cold energy storage.
研究领域:
材料科学
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能源技术
✓ 已验证
DOI
高影响因子
ENERGY CONVERSION AND MANAGEMENT
·
2017
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IF 5.589
Shile Shen,Shujuan Tan,Sai Wu,Cheng Guo,Juan Liang,Qian Yang,Guoyue Xu,Jie Deng
Three different methods, acid oxidation, mechanochemical process and ball milling, were used to modify multi-walled carbon nanotubes (MWCNTs). The MWCNTs were dispersed into erythritol (Ery) to prepare composite phase change materials (PCMs). The effects of the MWCNTs on the thermal properties of erythritol-based composite PCMs were studied experimentally. FT-IR and XPS spectroscopy show that hydroxyl groups and carboxylic groups were generated on the surface of the MWCNTs after modification. The pretreatment of MWCNTs can improve their dispersibility in erythritol. When the mass fraction of MWCNTs was 1%, the thermal conductivity of Ery was increased obviously from 0.1956 W/(m·K) to 0.9779 W/(m·K). Besides, the MWCNTs could help improve the supercooling and solidification enthalpy of erythritol significantly. When the mass fraction of A-MWCNTs was only 0.5%, the freezing temperature of PCMs increased from 18.8 °C to 58.15 °C and the solidification enthalpy increased 50 J/g. After 10 heating and cooling cycles, the Ery/A-MWCNTs composites show a very good thermal cycling stability.
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 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
SOLAR ENERGY MATERIALS AND SOLAR CELLS
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2021
·
IF 7.267
Liu Liu,Jianlei Niu,Jian-Yong Wu
This study was to develop stable phase change material (PCM)-water nano-emulsions with low supercooling and low viscosity using two-surfactant mixtures by the phase inversion temperature (PIT) method. The PCM agent n-hexadecane was mixed with Brij L4 as the primary surfactant and polyethylene-block-poly(ethylene glycol) (PE- b -PEG), Tween 60 or Tween 80 as a co-surfactant to form stable nano-emulsions. The results showed that the droplet size , viscosity and PIT point as well as the stability of PCM nano-emulsions were strongly dependent on the combination, mass ratio and total concentration of the two surfactants. In 25% (w/w) PCM nano-emulsions, an optimum formulation was the surfactant combination of Brij L4 and Tween 60 at 6:4 mass ratio, mixed with PCM at 11:20 mass ratio. The corresponding nano-emulsion had a high stability, a small droplet size of 60 nm and desirable Newtonian fluid behaviour with a relatively low viscosity of 50 mPa s. The addition of n-octacosane as a nucleating agent was effective to reduce the emulsion supercooling, though the supercooling degree was notably increased after multiple thermal cycles. The optimized 25% PCM nano-emulsion with 2% (w/w) n-octadecane showed an excellent stability over 120 days and 300 thermal cycles with a droplet size below 80 nm, a supercooling degree of ~5 °C and a latent heat of ~50 J/g, which was very promising for further development and application as a cooling storage medium.
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
DOI
高影响因子
ChemistrySelect
·
2025
·Vol. 10
·期 9
·e202405355
·
IF 2
Shaogang Zhang,Xiaolong Ma,Xin Min,Xiaoguang Zhang,Jinhong Li
Graphical A series of EV-CaCl2·6H2O composite PCMs were prepared. SrCl2·6H2O and copper nanoparticles affect the supercooling and thermal conductivity of EV-CaCl2·6H2O composite PCMs, respectively. The non-isothermal melt crystallization process and crystallization activation energy were studied. Solid-liquid phase change materials (PCMs) made from calcium chloride hexahydrate (CaCl 2 ·6H 2 O) offer benefits such as significant latent heat during phase change, high heat storage efficiency, low preparation costs, a nearly constant temperature exothermic process, and environmentally friendly attributes. However, they also face challenges like poor thermal conductivity, susceptibility to leakage, supercooling, and phase separation. The melt impregnation method prepared shape-stable composite PCMs using expanded vermiculite (EV) and CaCl 2 ·6H 2 O as raw materials. The layered pore structure of EV can be used as an encapsulation matrix to prevent the leakage of the CaCl 2 ·6H 2 O liquid phase. Adding 1 wt% strontium chloride hexahydrate (SrCl 2 ·6H 2 O) nucleating agent and 3 wt% copper nanoparticle thermal conductivity enhancer can reduce the supercooling by 8 °C and increase the thermal conductivity by 0.2092 W/(m·K). The kinetic equation effectively describes the non-isothermal melt crystallization process. An increase in the cooling rate creates a thermal hysteresis effect on melt crystallization; the faster the cooling rate, the lower the temperature at which crystallization begins and the shorter the duration required for crystallization to complete. Both SrCl 2 ·6H 2 O and copper nanoparticles can reduce the crystallization activation energy, which is the essential reason for lowering the supercooling of CaCl 2 ·6H 2 O.
研究领域:
材料科学
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化学工程
✓ 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）