Effects of some nucleating agents on the supercooling of erythritol to be applied as phase change material

Zeng, Ju‐Lan; Zhou, Lei; Zhang, Yuefei; Sun, Sai-Ling; Chen, Yuhang; Shu, Li; Yu, Linping; Zhu, Ling; Song, Liubin; Cao, Zhong

doi:10.1007/s10973-017-6296-2

Cited by 38 publications

(11 citation statements)

References 32 publications

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“…In contrast to the fatty acids, some other organic materials such as sugar alcohols require significant supercooling for the crystallization of the solid phase: liquid erythritol is often observed to supercool >80 K without crystallization. 15 However, sugar alcohols also have exceptionally high values of Δ fus H, 324 J g −1 for erythritol, for example. 16 As such, suppression of supercooling in sugar alcohol PCMs is an attractive target as it would allow them to be used in a wider range of applications.…”

Section: Introductionmentioning

confidence: 99%

Supercooling and Nucleation of Fatty Acids: Influence of Thermal History on the Behavior of the Liquid Phase

et al. 2018

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Saturated fatty acids are an exceptionally important class of liquids, used in many consumer products and suggested as phase change materials (PCMs) for thermal energy storage, in part because they crystallize with minimal supercooling. Here we investigate fatty acid nucleation to understand why crystallization is so facile, as a step toward identifying potential mechanisms for the suppression of supercooling in other PCMs. We find that fatty acid supercooling can be induced only if the liquid is first heated above a material-dependent threshold temperature. NMR spin–lattice relaxation time studies show that the average mobility of the alkyl chains in the fatty acids increases more rapidly with temperature above the supercooling threshold temperature, and NMR T 1 hysteresis also sets in at that temperature. Measurements of the real portion of the dielectric constant as a function of temperature show that a liquid fatty acid heated far above its melting point behaves with an apparent temperature upon cooling that is higher than the actual temperature, when compared to its behavior at the same temperature upon heating. Our results suggest that molecular clusters in the liquid fatty acids break apart when the liquids are heated above their threshold temperature and do not immediately re-form on cooling. The breakup of clusters leads to an increase in the mobility of the fatty acid molecules. Because the clusters do not re-form quickly on subsequent cooling, nucleation does not occur, and substantial supercooling results.

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Section: Introductionmentioning

confidence: 99%

Supercooling and Nucleation of Fatty Acids: Influence of Thermal History on the Behavior of the Liquid Phase

et al. 2018

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“…According to a recent review done by Safari et al the main methods to reduce supercooling degree are divided in two ways: adding nucleating agent and microencapsulation. Zeng et al added nine different nucleating agents to reduce the supercooling of erythritol. The result showed that Mg 3 BTC 2 ‐ and Ca 3 BTC 2 are the best nucleating agents.…”

Section: Introductionmentioning

confidence: 99%

End group modification of polyethylene glycol (PEG): A novel method to mitigate the supercooling of PEG as phase change material

et al. 2018

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Summary Polyethylene glycol (PEG) is a kind of phase change material with high phase change enthalpy and good compatibility with the environment. However, there is relatively large supercooling for PEG, limiting their practical applications. To reduce their supercooling degree, herein we use three different small molecules (acryloyl chloride, acetyl chloride, and thionyl chloride) to modify PEG and study the effects of different end group modification on their phase change properties. Fourier‐transform infrared (FTIR) and proton nuclear magnetic resonance (1H‐NMR) spectroscopy are used to confirm the molecular structure of the PEG with different molecular weights and functionalities after chemical modification. Crystal structures of the PEG before and after the modification are verified by X‐ray diffractometry (XRD) method and show no change. Differential scanning calorimetry (DSC) results show that the end group modification is quite effective for mitigating the supercooling of PEG with double ‐OH end groups but not effective for PEG with mono ‐OH end group. The mechanism for the change of supercooling behavior is proposed. The costs of different modification methods are estimated and compared.

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“…This undesirable behavior can lead to the inability of the PCM to release its stored latent heat of fusion in a predictable fashion. In efforts to overcome supercooling, various techniques have been used including coldfinger techniques or additives such as nucleating agents, , such as oxides (e.g., CaO, ZnO, BaO, Al 2 O 3 ), nanoparticles (e.g., carbon nanotubes, graphite), and hydroxides (e.g., Ca(OH) 2 , Sr(OH) 2 , Mg(OH) 2 ). , To prevent phase separation, thickening agents or confinement techniques have been applied. However, thickeners help only temporarily and the anhydrous salt will still separate eventually .…”

Section: Emerging Materials Types For Intermediate Temperature Range ...mentioning

confidence: 99%

Phase Change Materials for Renewable Energy Storage at Intermediate Temperatures

et al. 2022

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Thermal energy storage technologies utilizing phase change materials (PCMs) that melt in the intermediate temperature range, between 100 and 220 °C, have the potential to mitigate the intermittency issues of wind and solar energy. This technology can take thermal or electrical energy from renewable sources and store it in the form of heat. This is of particular utility when the end use of the energy is also as heat. For this purpose, the material should have a phase change between 100 and 220 °C with a high latent heat of fusion. Although a range of PCMs are known for this temperature range, many of these materials are not practically viable for stability and safety reasons, a perspective not often clear in the primary literature. This review examines the recent development of thermal energy storage materials for application with renewables, the different material classes, their physicochemical properties, and the chemical structural origins of their advantageous thermal properties. Perspectives on further research directions needed to reach the goal of large scale, highly efficient, inexpensive, and reliable intermediate temperature thermal energy storage technologies are also presented. CONTENTS References R

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Effects of some nucleating agents on the supercooling of erythritol to be applied as phase change material

Cited by 38 publications

References 32 publications

Supercooling and Nucleation of Fatty Acids: Influence of Thermal History on the Behavior of the Liquid Phase

Supercooling and Nucleation of Fatty Acids: Influence of Thermal History on the Behavior of the Liquid Phase

End group modification of polyethylene glycol (PEG): A novel method to mitigate the supercooling of PEG as phase change material

Phase Change Materials for Renewable Energy Storage at Intermediate Temperatures

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