The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Sumin Kim - One of the best experts on this subject based on the ideXlab platform.
-
analysis on phase transition range of the pure and mixed phase change materials pcm using a thermostatic chamber test and differentiation
Journal of Thermal Analysis and Calorimetry, 2018Co-Authors: Seong Jin Chang, Su Gwang Jeong, Sumin KimAbstract:A phase change material (PCM) is a type of thermal storage material. The thermal performance of PCMs is evaluated by latent heat capacity and phase change temperature range. The phase change temperature of the phase change materials (PCM) is a critical factor in selecting a PCM. In this study, the conditions of physical and chemical bonding of PCMs including n-Octadecane, n-docosane, palm wax, and two types of mixed PCMs were analyzed using the differential scanning calorimetry and the Fourier transform infrared. The phase change temperature range of these PCMs were analyzed using a thermostatic chamber test. In addition, the analysis method of the phase transition range of these PCMs was studied using the first and second derivatives. As a result, the phase changes of n-Octadecane, n-docosane, and palm wax occurred at 27, 43, and 45–62 °C, respectively. It is not possible to determine the exact temperature at which phase change occurs with palm wax because palm wax includes various acids. Also, the results of the mixed PCM of n-Octadecane and palm wax indicate several peaks. Finally, through a second derivative, it proved that the mixed PCM of n-Octadecane and palm wax melts at 18.3–29.1 and 35.1–42.9 °C and freezes at 48.4–51.8, 31.8–34.1, and 23.7–26.9 °C.
-
development of thermal enhanced n Octadecane porous nano carbon based materials using 3 step filtered vacuum impregnation method
Thermochimica Acta, 2017Co-Authors: Jongki Lee, Su Gwang Jeong, Seong Jin Chang, Sumin KimAbstract:In this study, n-Octadecane/porous nano carbon-based materials (OPNCs) were thermally enhanced using a 3-step filtered vacuum impregnation method. n-Octadecane as phase change materials (PCMs) and supporting materials of C-300, C-500, Activated carbon (AC), Expanded graphite (EG) and Exfoliated graphite nanoplatelets (xGnP) made of the same raw material. Through scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) analysis, n-Octadecane was well impregnated in carbon-based materials not a chemical bonding. Thermal conductivities of OPNCs were increased up to 580% compared with n-Octadecane by TCi. Dfferential scanning calorimetry (DSC) analysis was used to verify thermal performance of OPNCs, the latent heat capacities of OPNCs were measured from 220J/g to 393J/g. Analysis of thermal stability by thermogravimetric analysis (TGA) showed that the impregnation ratio of OPNCs was about 56% and that of EG was 88.53%. 3-step filtered vacuum impregnation method manufactured a stable and thermally enhanced OPNCs.
-
Development of thermal enhanced n-Octadecane/porous nano carbon-based materials using 3-step filtered vacuum impregnation method
Thermochimica Acta, 2017Co-Authors: Jongki Lee, Su Gwang Jeong, Seong Jin Chang, Sumin KimAbstract:In this study, n-Octadecane/porous nano carbon-based materials (OPNCs) were thermally enhanced using a 3-step filtered vacuum impregnation method. n-Octadecane as phase change materials (PCMs) and supporting materials of C-300, C-500, Activated carbon (AC), Expanded graphite (EG) and Exfoliated graphite nanoplatelets (xGnP) made of the same raw material. Through scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) analysis, n-Octadecane was well impregnated in carbon-based materials not a chemical bonding. Thermal conductivities of OPNCs were increased up to 580% compared with n-Octadecane by TCi. Dfferential scanning calorimetry (DSC) analysis was used to verify thermal performance of OPNCs, the latent heat capacities of OPNCs were measured from 220J/g to 393J/g. Analysis of thermal stability by thermogravimetric analysis (TGA) showed that the impregnation ratio of OPNCs was about 56% and that of EG was 88.53%. 3-step filtered vacuum impregnation method manufactured a stable and thermally enhanced OPNCs.
-
thermal performance enhancement of mortar mixed with Octadecane xgnp sspcm to save building energy consumption
Solar Energy Materials and Solar Cells, 2014Co-Authors: Sughwan Kim, Su Gwang Jeong, Songyee Paek, Jeong Hun Lee, Sumin KimAbstract:Abstract The Octadecane/exfoliated graphite nanoplatelets (xGnP) shape-stabilized PCM (SSPCM) was prepared by impregnating Octadecane as the PCM into xGnP in a vacuum. Fourier transform infrared spectroscopy determined that the heat storage characteristics of Octadecane could integrate into the structure of xGnP due to its physical bonding, without a change in its chemical properties. Scanning electron microscopy images revealed that Octadecane was evenly dispersed in the pores of xGnP. Differential scanning calorimeter analysis displayed that the melting temperature range of the SSPCM was similar to that of pure Octadecane. Thermo gravimetric analysis measurements of the Octadecane/xGnP SSPCM determined that the percentage of impregnated Octadecane into xGnP was 55.9%, with 110.9 J/g of latent heat storage energy. In addition, mortar with the prepared SSPCM was investigated, in terms of developing advanced building materials with thermal energy storage properties. The purpose was to improve the thermal properties of mortar by using the latent heat storage of the Octadecane/xGnP SSPCM. In consequence, mortar preserved with the SSPCM could be utilized as a construction material that stored thermal energy, to result in saving in buildings energy consumption.
-
Thermal performance enhancement of mortar mixed with Octadecane/xGnP SSPCM to save building energy consumption
Solar Energy Materials and Solar Cells, 2014Co-Authors: Sughwan Kim, Su Gwang Jeong, Songyee Paek, Jeong Hun Lee, Sumin KimAbstract:Abstract The Octadecane/exfoliated graphite nanoplatelets (xGnP) shape-stabilized PCM (SSPCM) was prepared by impregnating Octadecane as the PCM into xGnP in a vacuum. Fourier transform infrared spectroscopy determined that the heat storage characteristics of Octadecane could integrate into the structure of xGnP due to its physical bonding, without a change in its chemical properties. Scanning electron microscopy images revealed that Octadecane was evenly dispersed in the pores of xGnP. Differential scanning calorimeter analysis displayed that the melting temperature range of the SSPCM was similar to that of pure Octadecane. Thermo gravimetric analysis measurements of the Octadecane/xGnP SSPCM determined that the percentage of impregnated Octadecane into xGnP was 55.9%, with 110.9 J/g of latent heat storage energy. In addition, mortar with the prepared SSPCM was investigated, in terms of developing advanced building materials with thermal energy storage properties. The purpose was to improve the thermal properties of mortar by using the latent heat storage of the Octadecane/xGnP SSPCM. In consequence, mortar preserved with the SSPCM could be utilized as a construction material that stored thermal energy, to result in saving in buildings energy consumption.
Su Gwang Jeong - One of the best experts on this subject based on the ideXlab platform.
-
analysis on phase transition range of the pure and mixed phase change materials pcm using a thermostatic chamber test and differentiation
Journal of Thermal Analysis and Calorimetry, 2018Co-Authors: Seong Jin Chang, Su Gwang Jeong, Sumin KimAbstract:A phase change material (PCM) is a type of thermal storage material. The thermal performance of PCMs is evaluated by latent heat capacity and phase change temperature range. The phase change temperature of the phase change materials (PCM) is a critical factor in selecting a PCM. In this study, the conditions of physical and chemical bonding of PCMs including n-Octadecane, n-docosane, palm wax, and two types of mixed PCMs were analyzed using the differential scanning calorimetry and the Fourier transform infrared. The phase change temperature range of these PCMs were analyzed using a thermostatic chamber test. In addition, the analysis method of the phase transition range of these PCMs was studied using the first and second derivatives. As a result, the phase changes of n-Octadecane, n-docosane, and palm wax occurred at 27, 43, and 45–62 °C, respectively. It is not possible to determine the exact temperature at which phase change occurs with palm wax because palm wax includes various acids. Also, the results of the mixed PCM of n-Octadecane and palm wax indicate several peaks. Finally, through a second derivative, it proved that the mixed PCM of n-Octadecane and palm wax melts at 18.3–29.1 and 35.1–42.9 °C and freezes at 48.4–51.8, 31.8–34.1, and 23.7–26.9 °C.
-
development of thermal enhanced n Octadecane porous nano carbon based materials using 3 step filtered vacuum impregnation method
Thermochimica Acta, 2017Co-Authors: Jongki Lee, Su Gwang Jeong, Seong Jin Chang, Sumin KimAbstract:In this study, n-Octadecane/porous nano carbon-based materials (OPNCs) were thermally enhanced using a 3-step filtered vacuum impregnation method. n-Octadecane as phase change materials (PCMs) and supporting materials of C-300, C-500, Activated carbon (AC), Expanded graphite (EG) and Exfoliated graphite nanoplatelets (xGnP) made of the same raw material. Through scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) analysis, n-Octadecane was well impregnated in carbon-based materials not a chemical bonding. Thermal conductivities of OPNCs were increased up to 580% compared with n-Octadecane by TCi. Dfferential scanning calorimetry (DSC) analysis was used to verify thermal performance of OPNCs, the latent heat capacities of OPNCs were measured from 220J/g to 393J/g. Analysis of thermal stability by thermogravimetric analysis (TGA) showed that the impregnation ratio of OPNCs was about 56% and that of EG was 88.53%. 3-step filtered vacuum impregnation method manufactured a stable and thermally enhanced OPNCs.
-
Development of thermal enhanced n-Octadecane/porous nano carbon-based materials using 3-step filtered vacuum impregnation method
Thermochimica Acta, 2017Co-Authors: Jongki Lee, Su Gwang Jeong, Seong Jin Chang, Sumin KimAbstract:In this study, n-Octadecane/porous nano carbon-based materials (OPNCs) were thermally enhanced using a 3-step filtered vacuum impregnation method. n-Octadecane as phase change materials (PCMs) and supporting materials of C-300, C-500, Activated carbon (AC), Expanded graphite (EG) and Exfoliated graphite nanoplatelets (xGnP) made of the same raw material. Through scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) analysis, n-Octadecane was well impregnated in carbon-based materials not a chemical bonding. Thermal conductivities of OPNCs were increased up to 580% compared with n-Octadecane by TCi. Dfferential scanning calorimetry (DSC) analysis was used to verify thermal performance of OPNCs, the latent heat capacities of OPNCs were measured from 220J/g to 393J/g. Analysis of thermal stability by thermogravimetric analysis (TGA) showed that the impregnation ratio of OPNCs was about 56% and that of EG was 88.53%. 3-step filtered vacuum impregnation method manufactured a stable and thermally enhanced OPNCs.
-
preparation of energy efficient paraffinic pcms expanded vermiculite and perlite composites for energy saving in buildings
Solar Energy Materials and Solar Cells, 2015Co-Authors: Okyoung Chung, Su Gwang JeongAbstract:Abstract This paper deals with the preparation, characterization, thermal properties and thermal reliability of form-stable composite phase change materials (PCMs), composed of n-Octadecane, expanded vermiculite, and perlite for thermal energy storage. The composite PCMs were prepared by incorporation of liquid n-Octadecane within the expanded vermiculite (eVMT) and expanded perlite (ePLT), using a vacuum impregnation method. The microstructures of n-Octadecane/expanded vermiculite and pearlite were characterized by scanning electron microscopy (SEM). Analysis of Fourier transform infrared spectroscopy (FT-IR) of the prepared composite PCMs showed good compatibility between n-Octadecane and the expanded vermiculite and pearlite. The thermal conductivities of composites were reduced, based on the TCi results. Differential scanning calorimetry (DSC) analysis indicated that the n-Octadecane/eVMT and n-odtadecane/ePLT composites maintained their large latent heat capacity and original phase change temperatures, due to large surface area and good dispersion of the eVMT and ePLT. TGA analysis revealed that the prepared composite PCMs had good thermal durability in the working temperature ranges. Therefore, n-Octadecane based composite PCMs can be considered as suitable candidates for latent heat thermal energy storage, with high thermal performance.
-
thermal performance enhancement of mortar mixed with Octadecane xgnp sspcm to save building energy consumption
Solar Energy Materials and Solar Cells, 2014Co-Authors: Sughwan Kim, Su Gwang Jeong, Songyee Paek, Jeong Hun Lee, Sumin KimAbstract:Abstract The Octadecane/exfoliated graphite nanoplatelets (xGnP) shape-stabilized PCM (SSPCM) was prepared by impregnating Octadecane as the PCM into xGnP in a vacuum. Fourier transform infrared spectroscopy determined that the heat storage characteristics of Octadecane could integrate into the structure of xGnP due to its physical bonding, without a change in its chemical properties. Scanning electron microscopy images revealed that Octadecane was evenly dispersed in the pores of xGnP. Differential scanning calorimeter analysis displayed that the melting temperature range of the SSPCM was similar to that of pure Octadecane. Thermo gravimetric analysis measurements of the Octadecane/xGnP SSPCM determined that the percentage of impregnated Octadecane into xGnP was 55.9%, with 110.9 J/g of latent heat storage energy. In addition, mortar with the prepared SSPCM was investigated, in terms of developing advanced building materials with thermal energy storage properties. The purpose was to improve the thermal properties of mortar by using the latent heat storage of the Octadecane/xGnP SSPCM. In consequence, mortar preserved with the SSPCM could be utilized as a construction material that stored thermal energy, to result in saving in buildings energy consumption.
Xiaoming Fang - One of the best experts on this subject based on the ideXlab platform.
-
thermal energy storage cement mortar containing n Octadecane expanded graphite composite phase change material
Renewable Energy, 2013Co-Authors: Zhengguo Zhang, Shuping Wang, Xiaoming FangAbstract:Here we demonstrate thermal energy storage cement mortar (TESCM) fabricated by integrating ordinary cement mortar with a composite phase change material (PCM) based on n-Octadecane and expanded graphite (EG). The mass percentage of n-Octadecane in the composite PCM can reach as high as 90% due to the excellent adsorption ability of EG, which endows the composite PCM with large latent heat. SEM images of the composite PCM show that n-Octadecane is adsorbed into the pores of EG and uniformly covers on the nanosheets of EG, which microstructure contributes to preventing leakage of melted n-Octadecane after it changes phase from solid state to liquid state. The n-Octadecane/EG composite PCM has a good compatibility with ordinary cement mortar, and does not obviously deteriorate the apparent densities of the TESCM samples. Based on the thermal energy storage performance evaluation, it is found that the TESCM containing the n-Octadecane/EG composite PCM plays a role in reducing the variation of indoor temperature, which helps to decrease the energy consumption for buildings.
-
Thermal energy storage cement mortar containing n-Octadecane/expanded graphite composite phase change material
Renewable Energy, 2013Co-Authors: Zhengguo Zhang, Shuping Wang, Xiaoming Fang, Guoquan Shi, Xiaohong LiuAbstract:Here we demonstrate thermal energy storage cement mortar (TESCM) fabricated by integrating ordinary cement mortar with a composite phase change material (PCM) based on n-Octadecane and expanded graphite (EG). The mass percentage of n-Octadecane in the composite PCM can reach as high as 90% due to the excellent adsorption ability of EG, which endows the composite PCM with large latent heat. SEM images of the composite PCM show that n-Octadecane is adsorbed into the pores of EG and uniformly covers on the nanosheets of EG, which microstructure contributes to preventing leakage of melted n-Octadecane after it changes phase from solid state to liquid state. The n-Octadecane/EG composite PCM has a good compatibility with ordinary cement mortar, and does not obviously deteriorate the apparent densities of the TESCM samples. Based on the thermal energy storage performance evaluation, it is found that the TESCM containing the n-Octadecane/EG composite PCM plays a role in reducing the variation of indoor temperature, which helps to decrease the energy consumption for buildings.
Gui Yin Fang - One of the best experts on this subject based on the ideXlab platform.
-
preparation and thermal properties of n Octadecane molecular sieve composites as form stable thermal energy storage materials for buildings
Energy and Buildings, 2012Co-Authors: Zhi Chen, Feng Shan, Lei Cao, Gui Yin FangAbstract:Abstract The n-Octadecane/molecular sieve 5A composites as form-stable thermal storage materials were prepared by adsorbing liquid n-Octadecane into the molecular sieve 5A. In the composites, the n-Octadecane was used as thermal storage material, and the molecular sieve 5A acted as the supporting material. Fourier transformation infrared (FT-IR) spectroscope and scanning electronic microscope (SEM) were used to determine the chemical structure and microstructure of the n-Octadecane/molecular sieve 5A composites. The thermal properties and thermal stability were investigated by a differential scanning calorimeter (DSC) and a thermogravimetry analyzer (TGA). The FT-IR analyses indicated that there is no chemical interaction between the n-Octadecane and molecular sieve 5A. The SEM results showed that the n-Octadecane was well adsorbed into the porous network of the molecular sieve 5A and there is no leakage of the n-Octadecane from the composites even when it is in the melting state. The DSC results indicated that the n-Octadecane/molecular sieve 5A composites exhibited the same phase change characteristics as the n-Octadecane and their latent heats increased with the increase of the n-Octadecane content in composites. The TGA results presented that the molecular sieve 5A can improve the thermal stability of the composites as form-stable thermal energy storage materials.
-
Preparation and thermal properties of n-Octadecane/molecular sieve composites as form-stable thermal energy storage materials for buildings
Energy and Buildings, 2012Co-Authors: Zhi Chen, Feng Shan, Lei Cao, Gui Yin FangAbstract:Abstract The n-Octadecane/molecular sieve 5A composites as form-stable thermal storage materials were prepared by adsorbing liquid n-Octadecane into the molecular sieve 5A. In the composites, the n-Octadecane was used as thermal storage material, and the molecular sieve 5A acted as the supporting material. Fourier transformation infrared (FT-IR) spectroscope and scanning electronic microscope (SEM) were used to determine the chemical structure and microstructure of the n-Octadecane/molecular sieve 5A composites. The thermal properties and thermal stability were investigated by a differential scanning calorimeter (DSC) and a thermogravimetry analyzer (TGA). The FT-IR analyses indicated that there is no chemical interaction between the n-Octadecane and molecular sieve 5A. The SEM results showed that the n-Octadecane was well adsorbed into the porous network of the molecular sieve 5A and there is no leakage of the n-Octadecane from the composites even when it is in the melting state. The DSC results indicated that the n-Octadecane/molecular sieve 5A composites exhibited the same phase change characteristics as the n-Octadecane and their latent heats increased with the increase of the n-Octadecane content in composites. The TGA results presented that the molecular sieve 5A can improve the thermal stability of the composites as form-stable thermal energy storage materials.
-
Synthesis and characteristics of form-stable n-Octadecane/expanded graphite composite phase change materials
Applied Physics A, 2010Co-Authors: Hui Xing Li, Xu Liu, Gui Yin FangAbstract:N-Octadecane/expanded graphite composite phase-change materials were prepared by absorbing liquid n-Octadecane into the expanded graphite. The n-Octadecane was used as the phase-change material for thermal energy storage, and the expanded graphite acted as the supporting material. Fourier transformation infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermal diffusivity measurement were used to determine the chemical structure, crystalline phase, microstructure and thermal diffusivity of the composite phase-change materials, respectively. The thermal properties and thermal stability were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DSC results indicated that the composite phase-change materials exhibited the same phase-transition characteristics as the n-Octadecane and their latent heat increased with the n-Octadecane content in composite phase-change materials. The SEM results showed that the n-Octadecane was well absorbed in the porous network of the expanded graphite, and there was no leakage of the n-Octadecane from the composites even when it was in the molten state.
-
Synthesis and characteristics of form-stable n-Octadecane/expanded graphite composite phase change materials
Applied Physics A, 2010Co-Authors: Xu Liu, Gui Yin FangAbstract:N-Octadecane/expanded graphite composite phase-change materials were prepared by absorbing liquid n-Octadecane into the expanded graphite. The n-Octadecane was used as the phase-change material for thermal energy storage, and the expanded graphite acted as the supporting material. Fourier transformation infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermal diffusivity measurement were used to determine the chemical structure, crystalline phase, microstructure and thermal diffusivity of the composite phase-change materials, respectively. The thermal properties and thermal stability were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DSC results indicated that the composite phase-change materials exhibited the same phase-transition characteristics as the n-Octadecane and their latent heat increased with the n-Octadecane content in composite phase-change materials. The SEM results showed that the n-Octadecane was well absorbed in the porous network of the expanded graphite, and there was no leakage of the n-Octadecane from the composites even when it was in the molten state.
-
synthesis and characteristics of form stable n Octadecane expanded graphite composite phase change materials
Applied Physics A, 2010Co-Authors: Xu Liu, Gui Yin FangAbstract:N-Octadecane/expanded graphite composite phase-change materials were prepared by absorbing liquid n-Octadecane into the expanded graphite. The n-Octadecane was used as the phase-change material for thermal energy storage, and the expanded graphite acted as the supporting material. Fourier transformation infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermal diffusivity measurement were used to determine the chemical structure, crystalline phase, microstructure and thermal diffusivity of the composite phase-change materials, respectively. The thermal properties and thermal stability were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DSC results indicated that the composite phase-change materials exhibited the same phase-transition characteristics as the n-Octadecane and their latent heat increased with the n-Octadecane content in composite phase-change materials. The SEM results showed that the n-Octadecane was well absorbed in the porous network of the expanded graphite, and there was no leakage of the n-Octadecane from the composites even when it was in the molten state.
Zhengguo Zhang - One of the best experts on this subject based on the ideXlab platform.
-
thermal energy storage cement mortar containing n Octadecane expanded graphite composite phase change material
Renewable Energy, 2013Co-Authors: Zhengguo Zhang, Shuping Wang, Xiaoming FangAbstract:Here we demonstrate thermal energy storage cement mortar (TESCM) fabricated by integrating ordinary cement mortar with a composite phase change material (PCM) based on n-Octadecane and expanded graphite (EG). The mass percentage of n-Octadecane in the composite PCM can reach as high as 90% due to the excellent adsorption ability of EG, which endows the composite PCM with large latent heat. SEM images of the composite PCM show that n-Octadecane is adsorbed into the pores of EG and uniformly covers on the nanosheets of EG, which microstructure contributes to preventing leakage of melted n-Octadecane after it changes phase from solid state to liquid state. The n-Octadecane/EG composite PCM has a good compatibility with ordinary cement mortar, and does not obviously deteriorate the apparent densities of the TESCM samples. Based on the thermal energy storage performance evaluation, it is found that the TESCM containing the n-Octadecane/EG composite PCM plays a role in reducing the variation of indoor temperature, which helps to decrease the energy consumption for buildings.
-
Thermal energy storage cement mortar containing n-Octadecane/expanded graphite composite phase change material
Renewable Energy, 2013Co-Authors: Zhengguo Zhang, Shuping Wang, Xiaoming Fang, Guoquan Shi, Xiaohong LiuAbstract:Here we demonstrate thermal energy storage cement mortar (TESCM) fabricated by integrating ordinary cement mortar with a composite phase change material (PCM) based on n-Octadecane and expanded graphite (EG). The mass percentage of n-Octadecane in the composite PCM can reach as high as 90% due to the excellent adsorption ability of EG, which endows the composite PCM with large latent heat. SEM images of the composite PCM show that n-Octadecane is adsorbed into the pores of EG and uniformly covers on the nanosheets of EG, which microstructure contributes to preventing leakage of melted n-Octadecane after it changes phase from solid state to liquid state. The n-Octadecane/EG composite PCM has a good compatibility with ordinary cement mortar, and does not obviously deteriorate the apparent densities of the TESCM samples. Based on the thermal energy storage performance evaluation, it is found that the TESCM containing the n-Octadecane/EG composite PCM plays a role in reducing the variation of indoor temperature, which helps to decrease the energy consumption for buildings.