Temperature Dependence of Enthalpy and Heat Capacity of Alkanes and Related Phase Change Materials (PCMs) with a Peltier-element-based Adiabatic Scanning Calorimeter

MRS Advances ◽  
2016 ◽  
Vol 1 (60) ◽  
pp. 3935-3940 ◽  
Author(s):  
Jan Leys ◽  
Christ Glorieux ◽  
Jan Thoen
Keyword(s):  
Heat Capacity ◽  
Phase Change ◽  
Temperature Dependence ◽  
Phase Change Materials ◽  
Storage Capacity ◽  
Thermal Storage ◽  
Scanning Calorimetry ◽  
Peltier Element ◽  
Simulation Input ◽  
Adiabatic Scanning Calorimeter

ABSTRACTResearch in the field of phase change materials (PCMs) requires that the temperature dependence of the thermal storage capacity be well known for the selection of PCMs as well as for simulation input. A differential scanning calorimeter (DSC) is often used, but it substantially misrepresents the true heat capacity in the vicinity of large-enthalpy phase transitions. Therefore, other suitable experimental techniques should be applied for the determination of the thermal storage capacity. Peltier-element-based adiabatic scanning calorimetry (pASC) measures the heat capacity and the enthalpy of PCMs in thermodynamic equilibrium, thus removing the rate dependence and deformation that are inherent to DSC. The technique is illustrated here by measurements on the pure alkane tricosane (C23), the commercial alkane mixture RT42 and its bound counterpart PX42.

scholarly journals Thermal Storage of Nitrate Salts as Phase Change Materials (PCMs)

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7223
Author(s):  
Marco A. Orozco ◽  
Karen Acurio ◽  
Francis Vásquez-Aza ◽  
Javier Martínez-Gómez ◽  
Andres Chico-Proano
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Sodium Nitrite ◽  
Phase Change Materials ◽  
Storage Capacity ◽  
Thermal Storage ◽  
Potassium Nitrate ◽  
Ternary Mixtures ◽  
Scanning Calorimetry ◽  
Nitrate Salts

This study presents the energy storage potential of nitrate salts for specific applications in energy systems that use renewable resources. For this, the thermal, chemical, and morphological characterization of 11 samples of nitrate salts as phase change materials (PCM) was conducted. Specifically, sodium nitrate (NaNO3), sodium nitrite (NaNO2), and potassium nitrate (KNO3) were considered as base materials; and various binary and ternary mixtures were evaluated. For the evaluation of the materials, differential Fourier transform infrared spectroscopy (FTIR), scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) to identify the temperature and enthalpy of phase change, thermal stability, microstructure, and the identification of functional groups were applied. Among the relevant results, sodium nitrite presented the highest phase change enthalpy of 220.7 J/g, and the mixture of 50% NaNO3 and 50% NaNO2 presented an enthalpy of 185.6 J/g with a phase change start and end temperature of 228.4 and 238.6 °C, respectively. This result indicates that sodium nitrite mixtures allow the thermal storage capacity of PCMs to increase. In conclusion, these materials are suitable for medium and high-temperature thermal energy storage systems due to their thermal and chemical stability, and high thermal storage capacity.

scholarly journals Measurements of Heat Capacity and Enthalpy of Phase Change Materials by Adiabatic Scanning Calorimetry

2011 ◽  
Vol 32 (5) ◽  
pp. 913-924 ◽  
Author(s):  
Patricia Losada-Pérez ◽  
Chandra Shekhar Pati Tripathi ◽  
Jan Leys ◽  
George Cordoyiannis ◽  
Christ Glorieux ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Phase Change ◽  
Phase Change Materials ◽  
Scanning Calorimetry ◽  
Adiabatic Scanning Calorimetry

Next Generation Phase Change Materials as Multifunctional Watery Suspension for Heat Transport and Heat Storage

2009 ◽  
Vol 1188 ◽  
Author(s):  
Milka Markova Hadjieva ◽  
Metodi Bozukov ◽  
Ivan Gutzov
Keyword(s):  
Phase Transition ◽  
Thermal Cycling ◽  
Phase Change ◽  
Heat Transport ◽  
Phase Change Materials ◽  
Storage Capacity ◽  
Heat Storage ◽  
Thermal Storage ◽  
Temperature Range ◽  
Cooling Technology

AbstractThe phase change materials (PCM) are known since years with high thermal storage capacity but with limited applications. The modified PCM mainly paraffin watery suspensions, so called PCM slurry, improve some PCM drawbacks (thermal conductivity) and as paraffin multifunctional fluids can work in both, heat transport and heat storage for cooling technology applications. The structural and thermophysical properties of two types PCM slurry were good basis for comparison of their efficiency: paraffin microcapsule slurry (A) and paraffin emulsion slurry (B), both working in temperature range of phase transition from 2-12 degreesC. The equipments as differential scanning calorimetry (DSC), model NETZSCH DSC 200 PC; scanning electron microscopy (SEM), JOEL model JSM-5510; hot stage optical microscopy, LINKAM model TMS 94 and hand made thermal cycling system operational with Danfoss cooling machine that ensured 2 kW cooling capacity at 40oC; gave accurate results, characterizing completely, from structural and thermal point of view both types of PCM multifunctional structured fluids. Structural stability of the advanced phase change multifunctional fluids was discussed on sample imaging in variable magnifications made by method of Hot Stage microscopy and precise SEM study. Systematization of the DSC results obtained, including temperature range of phase transition and thermal storage capacity, measured before and after repeatable thermal cycling of the PCM multifunctional fluids, allowed selection of the PCM slurry working samples with relatively high thermal capacity applicable to further development in prototypes. Heat absorbed/released, calculated by NETZSCH DSC software, was for PCM slurry A in the range of 80 to 82 kJ/kg, while PCM slurry B showed thermal storage capacity from 56 to 53 kJ/kg. Correlation between the structural properties and thermal storage capacity of the phase change multifunctional fluids led to practical conclusions concerning: homogeneity; crystal growth/conditions; structural compatibility between components; prediction of the heat flow behavior of multifunctional PCM slurries in cooling technology for storage and transport of heat.

Tuning the flexibility and thermal storage capacity of solid–solid phase change materials towards wearable applications

2020 ◽  
Vol 8 (38) ◽  
pp. 20133-20140
Author(s):  
Jinming Shi ◽  
Waseem Aftab ◽  
Zibin Liang ◽  
Kunjie Yuan ◽  
Muhammad Maqbool ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Phase Change ◽  
Phase Change Materials ◽  
Storage Capacity ◽  
Solid Phase ◽  
Thermal Storage

By tuning the molecular weight of the polyethylene glycol segment, the thermal storage capacity and flexibility of polyurethane-based phase change materials (PCMs) are engineered towards wearable applications.

scholarly journals Thermal conductivity of aerated concrete (AC) composites containing micro-encapsulated phase change materials

2019 ◽  
Vol 282 ◽  
pp. 02033
Author(s):  
Shuai-Qi Tian ◽  
Ming-Liang Qu ◽  
Li-Wu Fan ◽  
Zi-Tao Yu ◽  
Jian Ge
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Phase Change ◽  
Phase Change Materials ◽  
Storage Capacity ◽  
Volumetric Heat Capacity ◽  
Liquid Phases ◽  
Aerated Concrete ◽  
Insulation Performance ◽  
Composite Samples

Aerated concrete (AC) was incorporated with micro-encapsulated phase change materials (PCMs) to form a novel PCM-composite AC with improved thermal storage capacity. RT25 paraffin was selected as the PCM and the composite materials were prepared by adding micro-encapsulated paraffin as an ingredient at various loadings. The effective thermal conductivity of the composite samples was measured at both 17 ºC and 35 ºC, while the paraffin was in solid and liquid phases, respectively. The volumetric heat capacity of the composites were also measured. Results showed that both the thermal conductivity and volumetric heat capacity increase upon adding the micro-encapsulated paraffin. However, they were found to decrease when further increase the paraffin loading. The maximum thermal conductivity and volumetric heat capacity were enhanced by approximately 35% and 30% when the paraffin loadings were 1% wt. and 3% wt., respectively. Since the increase of thermal conductivity leads to the deterioration of the thermal insulation performance, the composite samples with 3% wt. micro-encapsulated paraffin with lower thermal conductivity but the highest volumetric heat capacity was exhibited to be more appropriate.

scholarly journals Special Issue “Advanced Phase Change Materials for Thermal Storage”

2021 ◽  
Vol 11 (4) ◽  
pp. 1390
Author(s):  
Rocío Bayón
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Thermal Storage ◽  
Research Topic ◽  
Special Issue ◽  
Advanced Phase

Thermal energy storage using phase change materials (PCMs) is a research topic that has attracted much attention in recent decades [...]

scholarly journals pH-controlled synthesis of sustainable lauric acid/SiO2 phase change material for scalable thermal energy storage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shafiq Ishak ◽  
Soumen Mandal ◽  
Han-Seung Lee ◽  
Jitendra Kumar Singh
Keyword(s):  
Electron Microscopy ◽  
Phase Change ◽  
Lauric Acid ◽  
Photoelectron Spectroscopy ◽  
Phase Change Materials ◽  
Precursor Solution ◽  
Thermal Reliability ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Heating And Cooling

AbstractLauric acid (LA) has been recommended as economic, eco-friendly, and commercially viable materials to be used as phase change materials (PCMs). Nevertheless, there is lack of optimized parameters to produce microencapsulated PCMs with good performance. In this study, different amounts of LA have been chosen as core materials while tetraethyl orthosilicate (TEOS) as the precursor solution to form silicon dioxide (SiO2) shell. The pH of precursor solution was kept at 2.5 for all composition of microencapsulated LA. The synthesized microencapsulated LA/SiO2 has been characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-Ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM). The SEM and TEM confirm the microencapsulation of LA with SiO2. Thermogravimetric analysis (TGA) revealed better thermal stability of microencapsulated LA/SiO2 compared to pure LA. PCM with 50% LA i.e. LAPC-6 exhibited the highest encapsulation efficiency (96.50%) and encapsulation ratio (96.15%) through Differential scanning calorimetry (DSC) as well as good thermal reliability even after 30th cycle of heating and cooling process.

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