Energies
·
2022
·Vol. 15
·期 15
·5354
·
IF 3.252
Hongbing Chen,Rui Zhao,Congcong Wang,Lianyuan Feng,Shuqian Li,Yutong Gong
In this paper, a new type of microencapsulated phase change materials (MPCMs) with docosane as the core and titanium dioxide (TiO2) as the shell was prepared by in situ polymerization. Its phase transition temperature was approximately 40 °C, and it can be used as a phase change material (PCM) in a low-temperature solar heat collection system. The properties of the new material were examined including the microstructure, the chemical elements on the surface of the microcapsules, and thermal conductivity. In addition, to obtain the optimized formula of the microcapsules, single-factor analysis on the emulsifier type, its mass fraction, ultrasonic oscillation time, pH, and core–shell ratio were performed. The results showed that the MPCMs prepared in this paper had a particle size of 2–5 μm and were spherical. Its surface was uniform and smooth without cracks, and the TiO2was well dispersed around the docosane, completely coating the docosane without impurities. The MPCMs had good performance in terms of thermal properties and heat storage when using 0.40% SDS as an emulsifier, 10 min ultrasonic, a 3.5 pH value, and a 1:1 core–shell ratio. However, the stirring method, time, and experimental reaction temperature also affected the properties of the material, which was not studied in this experiment. We will continue to study these factors in the future.Keywords:microencapsulated phase change material;core–shell ratio;nanoparticles;thermal property
研究领域:
材料科学
·
太阳能技术
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 11
·2441
·
IF 5
Weiping Li,Dajiang Mei,Jihu Wang,Hui Wu,Shaoguo Wen
Microencapsulated phase change materials (MCPCM) as a green energy storage material not only prevent leakage of phase change materials but also increase the heat transfer area of phase change materials. Extensive previous work has shown that the performance of MCPCM depends on the shell material and MCPCM with polymers, as the shell material suffers from low mechanical strength and low thermal conductivity. In this study, a novel MCPCM with hybrid shells of melamine-urea-formaldehyde (MUF) and sulfonated graphene (SG) was prepared by in situ polymerization using SG-stabilized Pickering emulsion as a template. The effects of SG content and core/shell ratio on the morphology, thermal properties, leak-proof properties, and mechanical strength of the MCPCM were investigated. The results showed that the incorporation of SG into the shell of MUF effectively improved the contact angles, leak-proof performance, and mechanical strength of the MCPCM. Specifically, the contact angles of MCPCM-3SG were reduced by 26°, the leakage rate was reduced by 80.7%, and the breakage rate after high-speed centrifugation was reduced by 63.6% compared to MCPCM without SG. These findings suggest that the MCPCM with MUF/SG hybrid shells prepared in this study has great potential for application in thermal energy storage and management systems.Keywords:microencapsulated phase change materials;sulfonated graphene;Pickering emulsion
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 MATERIALS SCIENCE
·
2017
·Vol. 53
·期 4
·2566-2575
·
IF 2.599
Yang Wenbin,Zhang Li,Guo Yongli,Jiang Zhuoni,He Fangfang,Xie Changqiong,Fan Jinghui,Wu Juying,Zhang Kai
Paraffin, due to its linear chain and saturated hydrocarbons with low thermal conductivity, is difficult to transfer energy effectively. Using amphiphilicity of graphene oxide (GO), Pickering emulsion of paraffin@GO was obtained and then paraffin@graphene microencapsulated phase change materials (MEPCMs) were achieved by chemical reduction through adding hydrazine hydrate. Thermally conductive PCMs with segregated structure were constructed by hot compression of paraffin@graphene microencapsules. Scanning electronic microscopy, differential scanning calorimetry and thermal conductivity test were used to characterize microstructure and thermal properties of MEPCMs. Meanwhile, the effect of graphene on the phase change latent heat and phase transition temperature was investigated. Results indicated that GO did not react with paraffin during the process of chemical reduction and the obtained MEPCMs were regular spheres. These MEPCMs had paraffin content of 99% or even more. Graphene working as shell materials increased the phase change latent heat of paraffin from 227.6 to 232.4 J/g, without affecting the phase transition temperature. The hot-compress molding makes graphene shell form segregated structure with more thermal pathways, further enhancing thermal conductivity. The segregated-structure PCMs with high latent heat and thermal conductivity can be applied in energy storage field.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2019
·
IF 6.019
Qihang Zhao,Fangfang He,Quanping Zhang,Jinghui Fan,Ren He,Kai Zhang,Hongjian Yan,Wenbin Yang
The superior thermal behavior and light-to-thermal energy conversion performance are crucial for microencapsulated phase change materials (microPCMs) in thermal energy management. In this work, a series of paraffin@graphene/melamine-formaldehyde microPCMs based on graphene Pickering stabilizer were prepared by in-situ polymerization. Graphene was served as a Pickering stabilizer. We have undertaken a comprehensive study of the effects of different graphene concentrations and core/shell ratio on the microPCMs. The leakage rate test showed that the leakage rate of the microPCMs with 0.2 wt% of graphene is decreased by 93.20% than that of the microPCMs without graphene. Graphene promotes light-to-thermal conversion efficiency of microPCMs, which reaches to 90.7%. Additionally, the optical microscope (OM) and scanning electron microscope (SEM) were used to characterize the morphology of the Pickering emulsion droplet and microPCMs, respectively. Thermal properties of microPCMs were evaluated by differential scanning calorimetry (DSC) and thermal conductivity test. The results indicated that the latent heat of the microPCMs with core/shell ratio of 4/1 is 204.0 J g −1 and thermal conductivity of that is 0.707 W m −1 K −1 . Furthermore, because of the leakage prevention performance, thermal conductivity and light-to-thermal conversion performance of microPCMs, it may be forecast that microPCMs possess significant applications in thermal energy storage management.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2023
·
IF 7.4
Dongdong Xu,Yun Huang,Wenwei Liu,Tong Sun,Meiju Zhang
High-performance thermal energy storage technology based on phase change material (PCM) plays an important role in reducing the building energy consumption and realizing efficient energy utilization. However, the drawbacks such as liquid phase leakage, poor thermal conductivity, and low cycle stability, significantly reduces its service life and limits its further application. In this paper, a new microencapsulated phase change material (MPCM) containing graphite-SiO 2 shell and eicosane-octadecane (E-O) core was prepared by the sol–gel method. A high thermal conductivity shell was successfully constructed inside the MPCM by double-layer encapsulation technology to accommodate the poor thermal conductivity of E-O. The prepared MPCM had core–shell structures and spherical morphologies, with great enhancement in the thermal conductivity. When the mass ratio of E-O/SiO 2 is 2:1, the encapsulation ratio reaches 71.2%, and the corresponding phase change enthalpy of the MPCM is 133.2 kJ/kg. The MPCM is further added to phosphogypsum (PG) which is a by-product of the wet-process production of phosphoric acid, to form composite MPCM. The compressive strength of the composite material is still as high as 5.8 MPa with 15% MPCM despite the negative effect on strength by MPCM. The PG-MPCM showed a good thermal storage capacity and compatibility, furthermore, the thermal stability was maintained also after 2000 thermal cycles. Therefore, the composite PG-MPCM developed in this work is capable of energy storage to reduce the building energy consumption and provides great potential in the PG resource utilization for enhanced environmental protection.
研究领域:
材料科学
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能源工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES
·
2024
·
IF 3.6
Dongyan Yang,Lei Ni,Luping Gu,Qiang Chen,Juncheng Jiang,Jimi Su
Thermal runaway accounts for a high proportion of chemical safety accidents and poses a serious threat to the operational safety of personnel. Phase change materials (PCMs) have a high enthalpy of melting, if the latent heat energy of their phase change can be stored and used to absorb the heat released during thermal runaway, this phenomenon can provide a new approach for the control of reaction thermal runaway. In this work, microencapsulated phase change materials (microPCMs) were prepared by the suspension polymerization method using n -octadecane as the core material and polystyrene (PS) as the shell material. The prepared microPCMs had regular spherical morphologies with smooth surfaces, and the average particle size was 7.54 μm, the thermal conductivity was 0.05964 W/m∙K. The melting enthalpy of the microPCMs was 142.2 J/g, and the encapsulation percentage of the PCMs was 62.15%. The synthesis of the n -butylmagnesium bromide Grignard reagent occurred via a strong exothermic reaction, which was very likely to lead to overpressure venting once control was lost. The prepared microPCMs were applied as inhibitors in this reaction to investigate the temperature control effect under different operating conditions. The results showed that the amount of microPCMs added, and the timing of the addition affected the control effect. The addition of microPCMs could effectively reduce the reaction temperature and slow the rate of temperature increase. Even in the event of an emergency situation, such as a control failure, time could be gained for other emergency measures, effectively reducing the probability of thermal runaway accidents.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2012
·
IF 3.487
Wei Li,Xing-xiang Zhang,Xue-chen Wang,Guo-yi Tang,Hai-feng Shi
A series of MicroPCMs with gelatin-gum arabic shell, polyurethane shell and styrene-based copolymer shell were fabricated via complex coacervation , interfacial polymerization and suspension polymerization , respectively. Furthermore, a novel MicroPCMs with styrene-divinylbenzene copolymer as inner shell and polyurethane as outer shell was investigated, where styrene and divinybenzene were employed both as cosolvent and shell-forming monomers . Macrocapsules containing MicroPCMs with calcium alginate as matrixes were also prepared by piercing-solidifying incuber method. The morphology and structure of these microcapsules and macrocapsules were characterized by scanning electron microscopy (SEM) and optical microscopy (OM). Fourier transform infrared spectroscopy (FTIR) was used to identify the chemical structure of different copolymer shells. The thermal differential scanning calorimetry (DSC) was employed to measure phase change temperature and enthalpy. In addition, the cross-section of MacroPCMs was characterized as well.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2023
·
IF 8.7
Xiaofeng Niu,Qing Ke,Zhaohua Wang,Junming Zhou,Honglin Dong,Omid Mahian
Building on previous findings that showed the efficacy of microencapsulated phase change materials (MicroPCM) in augmenting liquid desiccant dehumidification performance, this study endeavors to further explore the extent of the impact of MicroPCM in the regeneration and the entire dehumidification system. The results of the regeneration experiment on the microencapsulated phase change material slurry (MPCMS) reveal that the addition of MicroPCM impedes regeneration. Specifically, as the concentration of MicroPCM increases, both the regeneration rate and the MPCMS concentration after regeneration decrease, while the regeneration effectiveness exhibits an initial decline followed by an increase. An empirical correlation was proposed to predict the regeneration rate of MPCMS for their future application. The results showed that the addition of MicroPCM led to a decrease in the regeneration rate by as much as 48.1%, when compared to a pure LiCl solution. However, a simulation analysis of the entire system revealed that within a certain concentration range of MicroPCM addition, the coefficient of performance (COP) of the system could still be increased by up to 4.28%. This finding suggests that if a more suitable non-heating regeneration method were used, the addition of MicroPCM could further enhance the overall performance of the liquid desiccant dehumidification system.
研究领域:
建筑环境工程
·
能源工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2023
·
IF 6.9
Chenzhen Liu,Huanxin Cao,Peng Yang,Kun Huang,Zhonghao Rao
Microencapsulation technology solves the problems that phase change materials (PCM) are easy to leak, difficult to transport, and vulnerable to contamination. However, the shell materials are mostly organic materials with low thermal conductivity , which limits their specific application in the field of thermal energy storage . In this regard, in order to enhance the thermal conductivity, a novel type of microencapsulated phase change materials (MicroEPCM) based on an n-eicosane core and a phenol-formaldehyde resin shell modified by nano-BN and nano-SiC, respectively, were fabricated via in-situ polymerization method. The effect of the mass fractions (2, 4 and 6 wt%) of nano-additives on the performance of MicroEPCM-BN and MicroEPCM-SiC was systematically investigated. The morphology, chemical structure and thermal properties of modified MicroEPCM were characterized by SEM , FTIR, XRD and DSC , respectively, to determine the optimum incorporation of nano-additives. Conclusions are as follows: modified MicroEPCM still had a spherical morphology with an average particle size range of 2–8 μm. Furthermore, the addition of nano-additives significantly improved the thermal conductivity of MicroEPCM, and the thermal conductivity gradually increased with the progressive increase in nano-additives content. MicroEPCM-4%BN and MicroEPCM-6%SiC had the best overall performance with phase change enthalpies of 145.83J/g and 131.30J/g, respectively, and the thermal conductivity increased by 61 % and 97 %, respectively, compared to that of MicroEPCM without nano-additives. They also showed excellent thermal cycling and degradation stability. Consequently, MicroEPCM modified by nano-additives will have great potential for thermal energy storage applications.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
·
2023
·
IF 9.4
Linfeng Li,Yaoqi Huang,Wenbin Li,Liyi Zou,Xi Wu,Yuanyuan Li,Xiaomin Cheng
Microencapsulated phase change materials (MEPCMs) have different thermal conductivity requirements under various application conditions. Organic-shell MEPCMs currently dominate the microcapsule due to their easy availability. The aim of this paper is to regulate the thermal properties, especially the thermal conductivity, of organic-shell microcapsules. Herein, with the precision and uniformity of atomic layer deposition (ALD) coating, the thickness of ZnO coating is controlled on the surface of paraffin @ polymethyl methacrylate (PMMA) to realize the regulation of thermal properties of MEPCMs. The experimental results illustrate that the introduction of ALD ZnO shell abates the phase transition enthalpy of MEPCM, but it realizes the optimization of thermal stability and phase transition reversibility for MEPCMs, which is confirmed by the mechanical test results of microcapsules. Furthermore, it is particularly worth mentioning that the thermal conductivity of MEPCM can be adjusted from 0.16 to 1.99 W m −1 K −1 within the ALD cycle range given in this research. The equivalent thermal conductivity of MEPCM was verified by calculation, and the relationship between ALD treatment and thermal conductivity was obtained. This research provides a strategy for accurately regulating the thermal conductivity of phase change microcapsules, breaking through the bottleneck in the application of microcapsules.
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
ADVANCED MATERIALS
·
2025
·
IF 26.8
Mingtai Hou,Hao Chen,Song Li,Xinru Zhang,Jie Chen,Zeyi Jiang,Cunhai Wang,Nien-Chu Lai,Yulong Ding
Solar-thermal-electric conversion shows great promise, especially in off-grid aerospace and navigation. However, low output density and intermittency of solar energy limit its application. Herein, a microencapsulated phase change material (MPCMs) is designed with a n-Tetracosane core and TiO 2 /Ti 2 O 3 composite shell to address the above issue. The MPCM exhibits a latent heat of 144.5 J g −1 , a photothermal conversion efficiency of 93.7% and 100% energy storage capacity. The thermoelectric system resulting from coupling the multifunctional film composed of polydimethylsiloxane and MPCMs with the thermoelectric module is capable of successfully achieving adaptive 24 h uninterrupted power generation on account of its functions of photothermal conversion, energy storage, and radiative cooling. The output power density of the TES ranged from 6.1 to 21.1 W m −2 at light intensities of 1000–5000 W m −2 . The material design innovatively endows a single material with the functions of photothermal conversion, phase change energy storage, and radiative cooling, making it can adaptively harvest energy from both the sun and cold space. This multifunctional material offers new insights into the repeatable storage and high-quality utilization of solar energy, holding significant scientific implications for the development of all-day solar-thermal-electric power generation technology.
研究领域:
材料科学
·
能源技术
·
热力学
·
太阳能利用
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY
·
2021
·
IF 7.147
Songping Mo,Jiarong Ye,Lisi Jia,Ying Chen
Mono suspensions of either nanoparticles or microencapsulated phase change material (MPCM) capsules (microcapsules) have shown superior thermophysical properties and heat transfer performance for thermal management. In this study, hybrid suspensions of nanoparticles and MPCM particles were prepared to integrate the advantages of both materials. The properties of hybrid MPCM/nanoparticle suspensions were investigated in terms of dispersion stability and thermal conductivity , and the cooling performance of the hybrid suspensions on thermal management of light-emitting diodes (LED) were studied. The experimental results show that the addition of graphene oxide , titanium dioxide (TiO 2 ), and aluminum oxide (Al 2 O 3 ) nanoparticles effectively improved the dispersion stability of the MPCM suspension (MPCMS). The thermal conductivity of the MPCMS was enhanced by the TiO 2 and Al 2 O 3 nanoparticles. The hybrid MPCM/Al 2 O 3 suspensions, which exhibited remarkable improvement in both dispersion stability and thermal conductivity, were applied to an LED thermal management system. The results show that the cooling performance of the hybrid suspensions was enhanced compared with that of the mono suspensions of MPCM or nanoparticles. The optimal concentration of the hybrid suspension was obtained. The effects of inlet temperature of the hybrid suspensions on the cooling performance were studied.
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
危险品化学品经营许可证（带存储）