scholarly journals Thermal Analysis of Organic and Nanoencapsulated Electrospun Phase Change Materials

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 995
Author(s):  
Evdoxia Paroutoglou ◽  
Peter Fojan ◽  
Leonid Gurevich ◽  
Göran Hultmark ◽  
Alireza Afshari
Keyword(s):  
Phase Change ◽  
Latent Heat ◽  
Phase Change Materials ◽  
Electrospun Fiber ◽  
Sodium Dodecyl ◽  
Scanning Calorimetry ◽  
Electrospinning Technique ◽  
Improve Energy Efficiency ◽  
Change Temperature

Latent heat stored in phase change materials (PCM) can greatly improve energy efficiency in indoor heating/cooling applications. This study presents the materials and methods for the formation and characterization of a PCM layer for a latent heat thermal energy storage (LHTES) application. Four commercially available PCMs comprising the classes of organic paraffins and organic non-paraffins were selected for thermal storage application. Pure organic PCM and PCM in water emulsions were experimentally investigated. PCM electrospun microfibers were produced by a co-axial electrospinning technique, where solutions of Polycaprolactone (PCL) 9% w/v and 12% w/v in dichloromethane (DCM) were used as the fiber shell materials. PCM emulsified with sodium dodecyl sulfate (SDS), and Polyvinylalcohol 10% w/v (PVA) constituted the core of the fibers. The thermal behavior of the PCM, PCM emulsions, and PCM electrospun fibers were analyzed with differential scanning calorimetry (DSC). A commercial organic paraffin with a phase change temperature of 18 °C (RT 18) in its pure and emulsified forms was found to be a suitable PCM candidate for LHTES. The PVA-PCM electrospun fiber matrix of the organic paraffin RT18 with a PCL concentration of 12% w/v showed the most promising results leading to an encapsulation efficiency of 67%.

scholarly journals Investigation of Lactones as Innovative Bio-Sourced Phase Change Materials for Latent Heat Storage

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1300 ◽  
Author(s):  
Rebecca Ravotti ◽  
Oliver Fellmann ◽  
Nicolas Lardon ◽  
Ludger Fischer ◽  
Anastasia Stamatiou ◽  
...  
Keyword(s):  
Phase Change ◽  
Latent Heat ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Scanning Calorimetry ◽  
Latent Heat Storage ◽  
Chemical Structures ◽  
Wide Range ◽  
Temperature Ranges ◽  
Change Temperature

In the presented work, five bio-based and bio-degradable cyclic esters, i.e. lactones, have been investigated as possible phase change materials for applications in latent heat storage systems. Commercial natural lactones such as ε-caprolactone and γ-valerolactone were easily purchased through chemical suppliers, while 1,2-campholide, oxa-adamantanone and dibenzochromen-6-one were synthesized through Baeyer-Villiger oxidation. The compounds were characterized with respect to attenuated total reflectance spectroscopy and gas chromatography coupled with mass spectroscopy, in order to confirm their chemical structures and identity. Subsequently, thermogravimetric analysis and differential scanning calorimetry were used to measure the phase change temperatures, enthalpies of fusion, degradation temperatures, as well to estimate the degree of supercooling. The lactones showed a wide range of phase change temperatures from −40 °C to 290 °C, making them a high interest for both low and high temperature latent heat storage applications, given the lack of organic phase change materials covering phase change temperature ranges below 0 °C and above 80 °C. However, low enthalpies of fusion, high degrees of supercooling and thermal degradations at low temperatures were registered for all samples, rendering them unsuitable as phase change materials.

scholarly journals Characterization of Unripe and Mature Avocado Seed Oil in Different Proportions as Phase Change Materials and Simulation of Their Cooling Storage

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 107
Author(s):  
Evelyn Reyes-Cueva ◽  
Juan Francisco Nicolalde ◽  
Javier Martínez-Gómez
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Seed Oil ◽  
Energy System ◽  
Maturity Stage ◽  
Natural Environments ◽  
Renewable Materials ◽  
Scanning Calorimetry ◽  
Avocado Seed

Environmental problems have been associated with energy consumption and waste management. A solution is the development of renewable materials such as organic phase change materials. Characterization of new materials allows knowing their applications and simulations provide an idea of how they can developed. Consequently, this research is focused on the thermal and chemical characterization of five different avocado seed oils depending on the maturity stage of the seed: 100% unripe, 25% mature-75% unripe, 50% mature-50% unripe, 75% mature-25% unripe, and 100% mature. The characterization was performed by differential scanning calorimetry, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The best oil for natural environments corresponded to 100% matured seed with an enthalpy of fusion of 52.93 J·g−1, and a degradation temperature between 241–545 °C. In addition, the FTIR analysis shows that unripe seed oil seems to contain more lipids than a mature one. Furthermore, a simulation with an isothermal box was conducted with the characterized oil with an initial temperature of −14 °C for the isothermal box, −27 °C for the PCM box, and an ambient temperature of 25 °C. The results show that without the PCM the temperature can reach −8 °C and with it is −12 °C after 7 h, proving its application as a cold thermal energy system.

Characterization of Latent Heat-Releasing Phase Change Materials for Dermal Therapies

2011 ◽  
Vol 115 (16) ◽  
pp. 8369-8375 ◽  
Author(s):  
D. G. Wood ◽  
M. B. Brown ◽  
S. A. Jones ◽  
D. Murnane
Keyword(s):  
Phase Change ◽  
Latent Heat ◽  
Phase Change Materials

scholarly journals Characterization of Thermophysical Properties of Phase Change Materials Using Unconventional Experimental Technologies

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4687
Author(s):  
Arnold Martínez ◽  
Mauricio Carmona ◽  
Cristóbal Cortés ◽  
Inmaculada Arauzo
Keyword(s):  
Thermal Properties ◽  
Phase Change ◽  
Thermophysical Properties ◽  
Phase Change Materials ◽  
Small Sample ◽  
Alternative Methods ◽  
Accurate Estimation ◽  
Inhomogeneous Materials ◽  
Scanning Calorimetry

The growing interest in developing applications for the storage of thermal energy (TES) is highly linked to the knowledge of the properties of the materials that will be used for that purpose. Likewise, the validity of representing processes through numerical simulations will depend on the accuracy of the thermal properties of the materials. The most relevant properties in the characterization of phase change materials (PCM) are the phase change enthalpy, thermal conductivity, heat capacity and density. Differential scanning calorimetry (DSC) is the most widely used technique for determining thermophysical properties. However, several unconventional methods have been proposed in the literature, mainly due to overcome the limitations of DSC, namely, the small sample required which is unsuitable for studying inhomogeneous materials. This paper presents the characterization of two commercial paraffins commonly used in TES applications, using methods such as T-history and T-melting, which were selected due to their simplicity, high reproducibility, and low cost of implementation. In order to evaluate the reliability of the methods, values calculated with the proposed alternative methods are compared with the results obtained by DSC measurements and with the manufacturer’s technical datasheet. Results obtained show that these non-conventional techniques can be used for the accurate estimation of selected thermal properties. A detailed discussion of the advantage and disadvantage of each method is given.

Preparation and Characterization of Tetradecanol Microcapsule Phase Change Materials by Emulsion Polymerization

2015 ◽  
Vol 1089 ◽  
pp. 137-141 ◽  
Author(s):  
Xiao Qiu Song ◽  
Long Di Cao ◽  
Dan Dan Xu
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Result Show ◽  
Ft Ir ◽  
Latent Heats ◽  
Test Result

In this study, it was aimed at preparing and characterizating of poly (methyl methacrylate) (PMMA) shell microcapsules containing tetradecanol as phase change materials (PCMs) for thermal energy storage. The tetradecanol microcapsules were characterized by using scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The test result show that the contents of tetradecanol in microcapsules nearly 57.5% and the latent heats of melting and freezing were found to be 120.7 and 118.4 J/g. TGA analyses also indicated that the microPCMs degraded in two steps and have good thermal stability.

Polyethylene Glycol/Expanded Vermiculite Shape-Stabilized Composite Phase Change Materials for Thermal Energy Storage

2016 ◽  
Vol 847 ◽  
pp. 39-45
Author(s):  
Yong Deng ◽  
Jin Hong Li ◽  
Ting Ting Qian ◽  
Wei Min Guan ◽  
Xiang Wang
Keyword(s):  
Polyethylene Glycol ◽  
Phase Change ◽  
Latent Heat ◽  
Phase Change Materials ◽  
Vacuum Impregnation ◽  
Impregnation Method ◽  
Scanning Calorimetry ◽  
Heating And Cooling ◽  
Expanded Vermiculite ◽  
Composite Phase Change Materials

Polyethylene glycol (PEG)/ expanded vermiculite (EVMT) shape-stabilized composite phase change material (ss-CPCM) was prepared by a facile vacuum impregnation method. The maximum mass percentage for PEG retained in ss-CPCM was 75.1 wt.% due to specific non-uniform flat layers pore structure of EVMT. The scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR) analysis results indicated that the melted PEG was adsorbed on the surface and completely dispersed into the pores of EVMT and no chemical changes took place during the heating and cooling processes. X-ray diffraction (XRD) results showed that the crystal structure of PEG was not destroyed after impregnation whereas the crystallization process of PEG was greatly restrained. Differential scanning calorimetry (DSC) results indicated that ss-CPCM melted at 57.61°C with a latent heat of 103.1 J/g and solidified at 33.19°C with a latent heat of 88.29 J/g. In addition, the thermal conductivity of ss-CPCM reached 0.418W/m K. The ss-CPCM can be considered as promising candidate materials for building applications due to their suitable phase change temperature, large latent heat and excellent chemical compatibility.

Characterization Phase Change Materials (PCM) Using T-History Method

2016 ◽  
Author(s):  
Navin Kumar ◽  
Debjyoti Banerjee
Keyword(s):  
Phase Change ◽  
Experimental Validation ◽  
Phase Change Materials ◽  
Reference Sample ◽  
Cost Effective ◽  
Experimental Protocol ◽  
Scanning Calorimetry ◽  
Numerical Predictions ◽  
Change Material

“T-history method” is widely used for characterization of thermal properties of Phase Change Material (PCM). In this study improvements are proposed to the experimental protocol used in the conventional T-History method. Experimental validation of numerical predictions for various samples of PCM were performed using the proposed measurement technique. This enabled the evaluation of the improvements in the proposed approach as well as for analyzing the experimental results. This involved measurement of temperature at the surface and in the center of the PCM samples (as well as that of the reference sample materials). The proposed modifications enable enhanced accuracy for estimation of the material properties (when compared to the conventional approaches). The estimates from the proposed approach were observed to be within 10% of the measured values obtained using Differential Scanning Calorimetry (DSC). The proposed approach is amenable to testing large sample sizes, is simpler to implement, provides more rapid data collection and is more cost-effective than that obtained using standard DSC protocols.

Setting for the Application of Phase Change Paraffin in Block Masonry

2013 ◽  
Vol 448-453 ◽  
pp. 1308-1311
Author(s):  
Feng Jiang ◽  
Yong Le Hou ◽  
Yong Lin Hu ◽  
Wei Dong Zhu ◽  
Qing Hua Wang
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Latent Heat ◽  
Phase Change Materials ◽  
Liquid Paraffin ◽  
Change Temperature ◽  
Composite Phase Change Material ◽  
Heat Preservation ◽  
Solid Liquid ◽  
Change Material

This paper studies the insulation properties of masonry filling paraffin composite phase change material. With high density polyethylene (HDPE) as wrapping materials and solid-liquid mixing paraffin as phase change materials, solid-liquid mixed paraffin phase change material with different amount of admixture is prepared, and the problem of flowing after paraffin phase change is then solved. The phase change temperature and the phase change latent heat of composite phase change material with different amount of admixture are tested. The results showed that the composite material with 30% of 52 # solid paraffin, 70% of liquid paraffin, 70% of HDPE coating performs best as to the phase transition temperature and latent heat. On this basis, This paper studies the composite phase change wall with phase change materials 0%, 33%, 66% and100%. Results show that the composite phase change material wall’s heat preservation performance has significantly improved. the temperature fluctuation range of internal and external wall surface is 4.2 °C lower than unfilled wall.

Preparation and Study of Polyethylene Glycol (PEG)/Titanium Dioxide (TiO2) Phase Change Materials

2011 ◽  
Vol 284-286 ◽  
pp. 214-218 ◽  
Author(s):  
Hai Yang Kang ◽  
Gui Juan Li
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Sol Gel ◽  
Scanning Calorimetry ◽  
Dsc Measurements ◽  
Good Potential ◽  
Ft Ir ◽  
Change Temperature ◽  
Thermal Energy Storage Material ◽  
General Method

This paper adopted the general method of sol-gel to prepare a list of PEG/TiO2 phase change materials (PCMs). The chemical structure of the materials was investigated by FT-IR respectively. The infrared indicate that the materials have good chemical compatibility. The thermal properties of the samples were measured by differential scanning calorimetry(DSC) and thermogravimetry(TG). The surface topography and crystallized behavior of the materials were detected by SEM and XRD. The TG thermographs show the samples can sustain high temperature about 212°C. The DSC measurements display that the phase change temperature of the materials’ range from 52°C to 56°C. The results obtained from experiments show that the phase change materials possesses a good potential as a thermal energy storage material.

Sign in / Sign up

Export Citation Format

Share Document