INTERNATIONAL JOURNAL OF ENERGY RESEARCH
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2022
·Vol. 46
·期 11
·15722-15732
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IF 4.672
Yu Bai,Wenjuan Qiu,Shuangfeng Wang
Summary At present, there are few kinds of phase change materials that suitable for medium temperature heat storage. Among them, sugar alcohols have broad application prospects in the heat storage at medium temperature due to their suitable phase transition temperature. In this work, eutectic phase change material (PCM) was prepared with D-mannitol as PCM and KBr as melting point modifier. Expanded graphite (EG) was used as thermally conductive support network to prepare shape-stable composite phase change material (CPCM). The prepared CPCM—10% EG/PCM has an appropriate phase transition temperature (136.88°C), high phase melting enthalpy (215.7 J/g), and good photothermal conversion (81.9%). The thermal conductivity of 10% EG/PCM reached 6.01 W/(m K), which is approximately 10 times higher than D-mannitol (0.603 W/(m K)). Because of its excellent thermal properties, the applications of CPCM in energy storage and photothermal conversion can be further broadened.
研究领域:
材料科学
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能源存储
·
太阳能利用
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF THERMOPHYSICS
·
2020
·Vol. 41
·期 5
·1-12
·
IF 0.794
Mo Songping,He Lijuan,Jia Lisi,Chen Ying,Cheng Zhengdong
Thermophysical properties are important parameters that influence the performance of phase change materials (PCMs) and heat transfer fluids. Micro/nanoencapsulation is an effective technique for preventing leakage and enhancing thermophysical properties of PCMs. In the present study, novel d -mannitol nanocapsules with inorganic shells were synthesized as a medium-temperature PCM. The nanocapsulation was confirmed by scanning electronic microscopy. The specific heat and thermal diffusivity of the nanocapsules and their suspension with heat transfer oil as base fluid were measured by a differential scanning calorimeter and light flash apparatus. The thermal conductivity of the nanocapsule suspension was measured using a hot-disk thermal constants analyzer. The viscosity of the nanocapsule suspension was measured by a rotational rheometer. The results show that the thermal conductivity and thermal diffusivity of the nanocapsules were enhanced compared to the bulk of the PCM due to the inorganic shell. The specific heat, thermal conductivity, and viscosity of the nanocapsule suspension were increased compared to the base fluid. The potential of the nanocapsule suspension as a heat storage and transfer fluid was evaluated.
研究领域:
材料科学
·
热力学
✓ 已验证
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2020
·
IF 6.984
Lijuan He,Songping Mo,Pengcheng Lin,Lisi Jia,Ying Chen,Zhengdong Cheng
Sugar alcohols with high latent heat have great potential for medium temperature thermal energy storage . Micro/nano-encapsulation can effectively improve the performance of phase change materials (PCMs), such as avoiding leakage and enhancing thermophysical properties . However, only a few work have been reported on the microencapsulation of sugar alcohol, and the reported methods showed some drawbacks such as requiring strictly controlled reactions or resulting in disability for the capsules to solidify. This paper reports for the first time the synthesis and properties of nanocapsules of a sugar alcohol D-mannitol (DM) by a facile sol-gel method. The nanoencapsulation was confirmed by various characterization using Fourier transformation infrared spectroscope (FT-IR), X-ray diffractometer (XRD), and transmission electron microscope (TEM). Uniform size distribution of the nanoencapsulated DM (NEDM) in 100–200 nm was observed by scanning electron microscope (SEM). The phase change performance of the NEDMs were investigated by differential scanning calorimeter (DSC). The results show that the NEDMs with a melting temperature of 166.2 °C, a melting enthalpy of 220.3 J/g, and an encapsulation ratio of 76.5% were obtained. The thermal reliability of the NEDMs was demonstrated by thermal cycling experiments. The thermal stability of the NEDMs was enhanced compared to DM as investigated by thermogravimetric analyzer (TGA). The NEDMs exhibited great potential for applications in medium temperature thermal energy storage and transfer.
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
APPLIED ENERGY
·
2020
·
IF 8.848
Lijuan He,Songping Mo,Pengcheng Lin,Lisi Jia,Ying Chen,Zhengdong Cheng
Sugar alcohols have considerable potential for usage in medium-temperature thermal energy storage applications; however, they suffer from poor thermal reliability and low thermal conductivity . Nanoencapsulation is an effective approach to improve the thermal energy storage performance of the phase-change materials. Until now, nanoencapsulation of sugar alcohols with a high phase-change performance has been rarely reported. The objective of this study is to develop a method for the nanoencapsulation of sugar alcohols with an enhanced phase-change performance. D-mannitol nanocapsules with a silica–graphene oxide composite shell were synthesized and investigated to demonstrate the validity of this novel method. The morphology, size distribution, and core–shell microstructure of the nanocapsules were observed using a scanning electron microscope, particle size and zeta potential analyzer, and transmission electron microscope. In addition, the phase-change performance of the nanocapsules was studied using a differential scanning calorimeter, a thermogravimetric analyzer, and weight loss and appearance investigation. The results demonstrate that the melting and solidifying latent heat of the nanocapsules are 216.7 and 174.4 kJ/kg, respectively. The energy storage efficiency of the nanocapsules was 75.8% and its 96.1% was maintained after repeated thermal cycling. Compared with pure D-mannitol, the thermal conductivity of the nanocapsules was observed to increase by up to 128.6%. The novel nanocapsules exhibited good medium-temperature thermal energy storage prospects.
研究领域:
材料科学
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能源存储
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纳米技术
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
·
2023
·
IF 9.4
Yu Bai,Shuangfeng Wang
Accelerate the development of medium-temperature phase change materials (PCMs) with high enthalpy of phase change and light absorption capability is very important for medium-temperature energy storage and solar thermal utilization. However, low energy conversion capacity and easy leakage limit the practical application of PCMs. To improve these properties of materials, a MXene/DM aerogel composite phase change material was prepared by self-assembly followed by freeze-drying of d -mannitol (DM) and MXene nanosheets using a simple solution blending method. The MXene/DM containing 20 wt% MXene has a high enthalpy (H m ) of phase change (202.7 J/g) with phase change temperature (T m ) of 153.3 °C, and still has good shape stability at 170 °C without leakage. In addition, MXene/DM has strong absorption ability in UV–Vis-NIR regions, with significant solar-thermal conversion efficiency of 88.1 %. The results indicate that the MXene/DM aerogel have comprehensive performance and have promising applications in medium-temperature thermal storage and photothermal conversion.
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
New Biotechnology
·
2021
·
IF 5.079
Wen-Bin Su,Fei-Long Li,Xue-Yong Li,Xiao-Man Fan,Rui-Jiang Liu,Ye-Wang Zhang
L-Tagatose, a promising building block in the production of many value-added chemicals, is generally produced by chemical routes with a low yield, which may not meet the increasing demands. Synthesis of l -tagatose by enzymatic oxidation of d -galactitol has not been applied on an industrial scale because of the high cofactor costs and the lack of efficient cofactor regeneration methods. In this work, an efficient and environmentally friendly enzymatic method containing a galactitol dehydrogenase for d -galactitol oxidation and a water-forming NADH oxidase for regeneration of NAD + was first designed and used for l -tagatose production. Supplied with only 3 mM NAD + , subsequent reaction optimization facilitated the efficient transformation of 100 mM of d -galactitol into l -tagatose with a yield of 90.2 % after 12 h (obtained productivity: 7.61 mM.h −1 ). Compared with the current chemical and biocatalytic methods, the strategy developed avoids by-product formation and achieves the highest yield of l -tagatose with low costs. It is expected to become a cleaner and more promising route for industrial biosynthesis of l -tagatose.
研究领域:
生物技术
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生物化学
·
酶学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2025
·
IF 4.7
Mingyu Wang,Haofei Sun,Xinyi Bai,Bo Su,Kai Li,Shengbo Zhang,Hailin Cui,Cunlin Zhang,Zhaoxin Geng
Hypertension directly or indirectly accounts for over 10% of maternal deaths. L-methyldopa is a safe antihypertensive for pregnant women, yet its low aqueous solubility substantially reduces bioavailability. This study enhances L-methyldopa's solubility in simulated gastric and intestinal fluids through cocrystallization with D-mannitol, thereby improving bioavailability. The cocrystal was synthesized via slow solvent evaporation. Then, multiple characterization techniques including powder X-ray diffraction (PXRD), Raman spectroscopy (Raman), scanning electron microscopy (SEM), and differential scanning calorimetry-thermogravimetric analysis (DSC-TGA) were employed to confirm the formation of cocrystals and verify the crystal structure and purity. Subsequently, a terahertz time-domain spectroscopy (THz-TDS) system was used to measure the spectral properties of D-mannitol, L-methyldopa, physical mixture, and cocrystal, and it was found that terahertz absorption spectroscopy can effectively characterize the formation of cocrystals. Furthermore, we also performed DFT calculations to simulate the crystal structures of D-mannitol, L-methyldopa, and the corresponding cocrystal. By comparing the experimental and simulated terahertz absorption spectra, it was found that they showed good agreement. High-performance liquid chromatography (HPLC) measurements showed that, compared with pure L-methyldopa, the solubility of L-methyldopa in the cocrystal in simulated intestinal fluid and gastric fluid increased by 53% and 67% respectively. DSC-TGA analysis confirmed significantly enhanced thermal stability of the cocrystal. This work provides valuable methodological insights for pharmaceutical cocrystal development.
研究领域:
药学
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材料科学
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光谱学
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计算化学
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晶体工程
✓ 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）