The Experts below are selected from a list of 2976 Experts worldwide ranked by ideXlab platform
Guiyin Fang - One of the best experts on this subject based on the ideXlab platform.
-
Palmitic acid/Polyvinyl Butyral/expanded graphite composites as form-stable phase change materials for solar thermal energy storage
Applied Energy, 2018Co-Authors: Yaxue Lin, Chuqiao Zhu, Guruprasad Alva, Guiyin FangAbstract:Abstract In order to improve the performances of phase change material (PCM) in applications, a novel form-stable phase change materials were fabricated via solution blending method in this work. Palmitic acid (PA) was used as phase change material to release and absorb large amounts of latent heat at operating temperature. Polyvinyl Butyral (PVB) is the polymer that was used as supporting matrix to prevent the leakage of palmitic acid in melting state. Expanded graphite (EG) was used not only to enhance thermal conductivity of form-stable phase change materials, but also to help reduce leakage. A series of form-stable phase change materials were prepared, containing pure palmitic acid/Polyvinyl Butyral composites, and palmitic acid/Polyvinyl Butyral composites doped with expanded graphite of 3 wt%, 5 wt% and 7 wt%. Fourier transformation infrared spectroscope (FT-IR), X-ray diffractometer (XRD), scanning electronic microscope (SEM) and thermal gravimetric analyzer (TGA) were used to analyze the chemical structures, crystal structures, microstructure and thermal stability of the form-stable phase change materials. Thermal storage properties were determined by differential scanning calorimeter (DSC), the latent heat value of form-stable phase change material with the highest palmitic acid content (70 wt%) was 128.08 J/g, corresponding to melting point of 59.5 °C. The thermal conductivity of form-stable phase change materials which was measured by thermal conductivity meter (TCM) was greatly enhanced by expanded graphite, and the thermal conductivity of form-stable phase change materials can be increased 4.2 times by 7 wt% expanded graphite. Therefore, the novel form-stable phase change materials are promising in thermal energy storage systems, especially in low-temperature solar energy systems.
-
palmitic acid Polyvinyl Butyral expanded graphite composites as form stable phase change materials for solar thermal energy storage
Applied Energy, 2018Co-Authors: Yaxue Lin, Chuqiao Zhu, Guruprasad Alva, Guiyin FangAbstract:Abstract In order to improve the performances of phase change material (PCM) in applications, a novel form-stable phase change materials were fabricated via solution blending method in this work. Palmitic acid (PA) was used as phase change material to release and absorb large amounts of latent heat at operating temperature. Polyvinyl Butyral (PVB) is the polymer that was used as supporting matrix to prevent the leakage of palmitic acid in melting state. Expanded graphite (EG) was used not only to enhance thermal conductivity of form-stable phase change materials, but also to help reduce leakage. A series of form-stable phase change materials were prepared, containing pure palmitic acid/Polyvinyl Butyral composites, and palmitic acid/Polyvinyl Butyral composites doped with expanded graphite of 3 wt%, 5 wt% and 7 wt%. Fourier transformation infrared spectroscope (FT-IR), X-ray diffractometer (XRD), scanning electronic microscope (SEM) and thermal gravimetric analyzer (TGA) were used to analyze the chemical structures, crystal structures, microstructure and thermal stability of the form-stable phase change materials. Thermal storage properties were determined by differential scanning calorimeter (DSC), the latent heat value of form-stable phase change material with the highest palmitic acid content (70 wt%) was 128.08 J/g, corresponding to melting point of 59.5 °C. The thermal conductivity of form-stable phase change materials which was measured by thermal conductivity meter (TCM) was greatly enhanced by expanded graphite, and the thermal conductivity of form-stable phase change materials can be increased 4.2 times by 7 wt% expanded graphite. Therefore, the novel form-stable phase change materials are promising in thermal energy storage systems, especially in low-temperature solar energy systems.
-
Thermal and electrical characterization of polymer/ceramic composites with Polyvinyl Butyral matrix
Materials Chemistry and Physics, 2018Co-Authors: Guruprasad Alva, Yaxue Lin, Guiyin FangAbstract:Abstract As polymers have the ability to be easily molded in to any shape, they have a wide range of applications in industry. Composites prepared by dispersing ceramics in to polymer matrix have higher thermal conductivity than the original polymer, and they still retain their high electrical resistance. In this work, Polyvinyl Butyral (PVB) is chosen as the polymer matrix. Ceramic nanoparticles like boron nitride (BN), zinc oxide (ZnO) and silicon carbide (SiC) are used as fillers. Polymer composites with different filler loading ratio (wt %) are prepared and their thermal and electrical properties are analyzed. FT–IR, XRD and TGA characterizations are also performed on the composites. The results indicated that PVB composite with hexagonal boron nitride (h–BN) showed the best improvement in thermal conductivity up to 0.5194 W m−1.K−1 which is an increase of 131.87%, and volume resistivity of composites remained high, above the 1010 Ω–cm level.
-
thermal and electrical characterization of polymer ceramic composites with Polyvinyl Butyral matrix
Materials Chemistry and Physics, 2018Co-Authors: Guruprasad Alva, Yaxue Lin, Guiyin FangAbstract:Abstract As polymers have the ability to be easily molded in to any shape, they have a wide range of applications in industry. Composites prepared by dispersing ceramics in to polymer matrix have higher thermal conductivity than the original polymer, and they still retain their high electrical resistance. In this work, Polyvinyl Butyral (PVB) is chosen as the polymer matrix. Ceramic nanoparticles like boron nitride (BN), zinc oxide (ZnO) and silicon carbide (SiC) are used as fillers. Polymer composites with different filler loading ratio (wt %) are prepared and their thermal and electrical properties are analyzed. FT–IR, XRD and TGA characterizations are also performed on the composites. The results indicated that PVB composite with hexagonal boron nitride (h–BN) showed the best improvement in thermal conductivity up to 0.5194 W m−1.K−1 which is an increase of 131.87%, and volume resistivity of composites remained high, above the 1010 Ω–cm level.
Tai-huei Wei - One of the best experts on this subject based on the ideXlab platform.
-
Reverse saturable absorption of copper phthalocyanines in toluene and sol-gel tetraethyl orthosilicate/Polyvinyl Butyral hybrid film
Dyes and Pigments, 2004Co-Authors: W.b. Wang, Jun-rong Chen, Lung-chang Liu, Chia-hon Tai, Tai-huei WeiAbstract:Abstract Materials with strong reverse saturable absorption have been searched for power limiting applications, and metallophthalocyanine molecules are one of them. Here we report our investigations of reverse saturable absorptive properties of copper phthalocyanines with three different side substitutions. By dissolving them in toluene or incorporating them in polymer-silica hybrid material using a sol-gel process with Polyvinyl Butyral and tetraethyl orthosilicate as precursors, we found that substitution of copper phthalocyanines influence the optical nonlinearities. Regarding the preparation process of phthalocyanines in the solids, a new route has been successfully used.
-
reverse saturable absorption of copper phthalocyanines in toluene and sol gel tetraethyl orthosilicate Polyvinyl Butyral hybrid film
Dyes and Pigments, 2004Co-Authors: W.b. Wang, Jun-rong Chen, Lung-chang Liu, Chia-hon Tai, Tai-huei WeiAbstract:Abstract Materials with strong reverse saturable absorption have been searched for power limiting applications, and metallophthalocyanine molecules are one of them. Here we report our investigations of reverse saturable absorptive properties of copper phthalocyanines with three different side substitutions. By dissolving them in toluene or incorporating them in polymer-silica hybrid material using a sol-gel process with Polyvinyl Butyral and tetraethyl orthosilicate as precursors, we found that substitution of copper phthalocyanines influence the optical nonlinearities. Regarding the preparation process of phthalocyanines in the solids, a new route has been successfully used.
Jianfeng Yang - One of the best experts on this subject based on the ideXlab platform.
-
Characterization of defects of mullite fibers prepared by Polyvinyl Butyral as spinning aid
Science of Sintering, 2010Co-Authors: Y.b. Zhang, C.f. Xiao, Jianfeng YangAbstract:Mullite fibers have been synthesized using Polyvinyl Butyral as spinning aids. Defects including cracks, core-sheath structure, randomly arranged powders, shots and rough surface were observed. The results showed that circumferential cracks were terminated by the main axial crack. The thermal shrinkage could be considered as the reason for the formation of cracks and core-sheath structure. Improper control of heat treatment resulted in the rough surface around fibers. The wet gel fibers were easily inserted by some alumina powders which were used to obtain the uniform shrinkage during calcinations in the kiln.
-
mullite fibres prepared by sol gel method using Polyvinyl Butyral
Journal of The European Ceramic Society, 2009Co-Authors: Yabin Zhang, Yaping Ding, Jiqiang Gao, Jianfeng YangAbstract:Abstract Mullite fibres with uniform diameter and smooth surface have been synthesized using commercial grade Polyvinyl Butyral (PVB) as binder. The sol with good spinnablity was obtained at reaction temperature of 60 °C for 1 h. The results of X-ray diffraction indicated that the Al–Si spinel was obtained before complete mullization, which implied the addition of PVB retarded the phase transformation of mullite. The fibres showed a rough surface and lateral cracks at 800 °C. Smooth and dense surface was observed when fibres were sintered at 1200 °C and completed transformation to mullite was achieved. This technique offered the possibility of synthesizing mullite fibres at considerably lower cost than at present.
-
Mullite fibres prepared by sol–gel method using Polyvinyl Butyral
Journal of The European Ceramic Society, 2009Co-Authors: Yabin Zhang, Yaping Ding, Jiqiang Gao, Jianfeng YangAbstract:Abstract Mullite fibres with uniform diameter and smooth surface have been synthesized using commercial grade Polyvinyl Butyral (PVB) as binder. The sol with good spinnablity was obtained at reaction temperature of 60 °C for 1 h. The results of X-ray diffraction indicated that the Al–Si spinel was obtained before complete mullization, which implied the addition of PVB retarded the phase transformation of mullite. The fibres showed a rough surface and lateral cracks at 800 °C. Smooth and dense surface was observed when fibres were sintered at 1200 °C and completed transformation to mullite was achieved. This technique offered the possibility of synthesizing mullite fibres at considerably lower cost than at present.
-
Synthesis and characterization of Polyvinyl Butyral–Al(NO3)3 composite sol used for alumina based fibers
Journal of Sol-Gel Science and Technology, 2008Co-Authors: Yabin Zhang, Yaping Ding, Jiqiang Gao, Jianfeng YangAbstract:The Polyvinyl Butyral–Al(NO3)3 composite sol used for alumina based fibers was synthesized by the sol–gel process in an aqueous solution using the Polyvinyl Butyral (PVB) and Al(NO3)3 · 9H2O (AN). The alumina fibers with smooth surface and uniform diameter were prepared. PVB, AN, PVB–AN composite sol and alumina fibers have been studied by X-ray diffraction (XRD), derivative thermo-gravimetric/differential scanning calorimetry (DTG/DSC), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The interaction between PVB and AN was reported. The presence of a new weak peak at low angle and deviation of diffraction angle in XRD patterns implied that the reaction between PVB and AN took place. DTG/DSC curves showed the decomposition temperatures of AN increased and that of PVB decreased in the PVB–AN composite sol, which was considered to be caused by the interaction between PVB and AN. FTIR spectroscopy of PVB–AN gel showed a new absorption peak due to the COOH group, which implied the presence of new reaction product. The schematic reaction formula was shown in this paper. The XRD pattern of fibers sintered at 1,200 °C showed the formation of α-alumina and the fibers showed smooth surface and uniform diameter.
W.b. Wang - One of the best experts on this subject based on the ideXlab platform.
-
Reverse saturable absorption of copper phthalocyanines in toluene and sol-gel tetraethyl orthosilicate/Polyvinyl Butyral hybrid film
Dyes and Pigments, 2004Co-Authors: W.b. Wang, Jun-rong Chen, Lung-chang Liu, Chia-hon Tai, Tai-huei WeiAbstract:Abstract Materials with strong reverse saturable absorption have been searched for power limiting applications, and metallophthalocyanine molecules are one of them. Here we report our investigations of reverse saturable absorptive properties of copper phthalocyanines with three different side substitutions. By dissolving them in toluene or incorporating them in polymer-silica hybrid material using a sol-gel process with Polyvinyl Butyral and tetraethyl orthosilicate as precursors, we found that substitution of copper phthalocyanines influence the optical nonlinearities. Regarding the preparation process of phthalocyanines in the solids, a new route has been successfully used.
-
reverse saturable absorption of copper phthalocyanines in toluene and sol gel tetraethyl orthosilicate Polyvinyl Butyral hybrid film
Dyes and Pigments, 2004Co-Authors: W.b. Wang, Jun-rong Chen, Lung-chang Liu, Chia-hon Tai, Tai-huei WeiAbstract:Abstract Materials with strong reverse saturable absorption have been searched for power limiting applications, and metallophthalocyanine molecules are one of them. Here we report our investigations of reverse saturable absorptive properties of copper phthalocyanines with three different side substitutions. By dissolving them in toluene or incorporating them in polymer-silica hybrid material using a sol-gel process with Polyvinyl Butyral and tetraethyl orthosilicate as precursors, we found that substitution of copper phthalocyanines influence the optical nonlinearities. Regarding the preparation process of phthalocyanines in the solids, a new route has been successfully used.
Yaxue Lin - One of the best experts on this subject based on the ideXlab platform.
-
Palmitic acid/Polyvinyl Butyral/expanded graphite composites as form-stable phase change materials for solar thermal energy storage
Applied Energy, 2018Co-Authors: Yaxue Lin, Chuqiao Zhu, Guruprasad Alva, Guiyin FangAbstract:Abstract In order to improve the performances of phase change material (PCM) in applications, a novel form-stable phase change materials were fabricated via solution blending method in this work. Palmitic acid (PA) was used as phase change material to release and absorb large amounts of latent heat at operating temperature. Polyvinyl Butyral (PVB) is the polymer that was used as supporting matrix to prevent the leakage of palmitic acid in melting state. Expanded graphite (EG) was used not only to enhance thermal conductivity of form-stable phase change materials, but also to help reduce leakage. A series of form-stable phase change materials were prepared, containing pure palmitic acid/Polyvinyl Butyral composites, and palmitic acid/Polyvinyl Butyral composites doped with expanded graphite of 3 wt%, 5 wt% and 7 wt%. Fourier transformation infrared spectroscope (FT-IR), X-ray diffractometer (XRD), scanning electronic microscope (SEM) and thermal gravimetric analyzer (TGA) were used to analyze the chemical structures, crystal structures, microstructure and thermal stability of the form-stable phase change materials. Thermal storage properties were determined by differential scanning calorimeter (DSC), the latent heat value of form-stable phase change material with the highest palmitic acid content (70 wt%) was 128.08 J/g, corresponding to melting point of 59.5 °C. The thermal conductivity of form-stable phase change materials which was measured by thermal conductivity meter (TCM) was greatly enhanced by expanded graphite, and the thermal conductivity of form-stable phase change materials can be increased 4.2 times by 7 wt% expanded graphite. Therefore, the novel form-stable phase change materials are promising in thermal energy storage systems, especially in low-temperature solar energy systems.
-
palmitic acid Polyvinyl Butyral expanded graphite composites as form stable phase change materials for solar thermal energy storage
Applied Energy, 2018Co-Authors: Yaxue Lin, Chuqiao Zhu, Guruprasad Alva, Guiyin FangAbstract:Abstract In order to improve the performances of phase change material (PCM) in applications, a novel form-stable phase change materials were fabricated via solution blending method in this work. Palmitic acid (PA) was used as phase change material to release and absorb large amounts of latent heat at operating temperature. Polyvinyl Butyral (PVB) is the polymer that was used as supporting matrix to prevent the leakage of palmitic acid in melting state. Expanded graphite (EG) was used not only to enhance thermal conductivity of form-stable phase change materials, but also to help reduce leakage. A series of form-stable phase change materials were prepared, containing pure palmitic acid/Polyvinyl Butyral composites, and palmitic acid/Polyvinyl Butyral composites doped with expanded graphite of 3 wt%, 5 wt% and 7 wt%. Fourier transformation infrared spectroscope (FT-IR), X-ray diffractometer (XRD), scanning electronic microscope (SEM) and thermal gravimetric analyzer (TGA) were used to analyze the chemical structures, crystal structures, microstructure and thermal stability of the form-stable phase change materials. Thermal storage properties were determined by differential scanning calorimeter (DSC), the latent heat value of form-stable phase change material with the highest palmitic acid content (70 wt%) was 128.08 J/g, corresponding to melting point of 59.5 °C. The thermal conductivity of form-stable phase change materials which was measured by thermal conductivity meter (TCM) was greatly enhanced by expanded graphite, and the thermal conductivity of form-stable phase change materials can be increased 4.2 times by 7 wt% expanded graphite. Therefore, the novel form-stable phase change materials are promising in thermal energy storage systems, especially in low-temperature solar energy systems.
-
Thermal and electrical characterization of polymer/ceramic composites with Polyvinyl Butyral matrix
Materials Chemistry and Physics, 2018Co-Authors: Guruprasad Alva, Yaxue Lin, Guiyin FangAbstract:Abstract As polymers have the ability to be easily molded in to any shape, they have a wide range of applications in industry. Composites prepared by dispersing ceramics in to polymer matrix have higher thermal conductivity than the original polymer, and they still retain their high electrical resistance. In this work, Polyvinyl Butyral (PVB) is chosen as the polymer matrix. Ceramic nanoparticles like boron nitride (BN), zinc oxide (ZnO) and silicon carbide (SiC) are used as fillers. Polymer composites with different filler loading ratio (wt %) are prepared and their thermal and electrical properties are analyzed. FT–IR, XRD and TGA characterizations are also performed on the composites. The results indicated that PVB composite with hexagonal boron nitride (h–BN) showed the best improvement in thermal conductivity up to 0.5194 W m−1.K−1 which is an increase of 131.87%, and volume resistivity of composites remained high, above the 1010 Ω–cm level.
-
thermal and electrical characterization of polymer ceramic composites with Polyvinyl Butyral matrix
Materials Chemistry and Physics, 2018Co-Authors: Guruprasad Alva, Yaxue Lin, Guiyin FangAbstract:Abstract As polymers have the ability to be easily molded in to any shape, they have a wide range of applications in industry. Composites prepared by dispersing ceramics in to polymer matrix have higher thermal conductivity than the original polymer, and they still retain their high electrical resistance. In this work, Polyvinyl Butyral (PVB) is chosen as the polymer matrix. Ceramic nanoparticles like boron nitride (BN), zinc oxide (ZnO) and silicon carbide (SiC) are used as fillers. Polymer composites with different filler loading ratio (wt %) are prepared and their thermal and electrical properties are analyzed. FT–IR, XRD and TGA characterizations are also performed on the composites. The results indicated that PVB composite with hexagonal boron nitride (h–BN) showed the best improvement in thermal conductivity up to 0.5194 W m−1.K−1 which is an increase of 131.87%, and volume resistivity of composites remained high, above the 1010 Ω–cm level.
