The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform

Yi Long - One of the best experts on this subject based on the ideXlab platform.

  • Index-tunable anti-reflection coatings: Maximizing solar modulation ability for vanadium dioxide-based smart Thermochromic glazing
    Journal of Alloys and Compounds, 2018
    Co-Authors: Chang Liu, Schlomo Magdassi, Chor Yong Tay, Shancheng Wang, Daniel Mandler, Qi Lu, Haibo Yang, Yang Zhou, Yi Long
    Abstract:

    Vanadium dioxide (VO2) nanoparticles with reversible semiconductor-metal phase transition holds the tremendous potential as a Thermochromic Material for the energy-saving smart glazing. However, the trade-off between improving the luminous transmittance (Tlum) while sacrificing the solar modulation ability (ΔTsol) hampers its bench-to-market translation. Previous studies of anti-reflection coatings (ARCs) focused primarily on increasing Tlumwhile neglecting ΔTsol, which is a key energy-saving determinant. The intrinsically low ΔTsol(

  • Tungsten doped VO2/microgels hybrid Thermochromic Material and its smart window application
    RSC Advances, 2017
    Co-Authors: Yong Sheng Yang, Freddy Boey Yin Chiang, Yang Zhou, Yi Long
    Abstract:

    Thermal sensitive microgels were synthesized directly from hydroxypropyl cellulose (HPC) and acrylic acid (AA) in pure water. The first cloud point temperature, near 45 °C, of the inorganic/organic hybrid Thermochromic Material was obtained by dispersing W doped VO2 in HPCA microgels and the composite microgel is highly transparent at room temperature with Tlum = 80% when the thickness is 25 μm. The excellent solar modulating ability (ΔTsol) of 36%, high averaged Tlum of 56% and relatively high cloud point temperature of 50 °C make it suitable for smart windows applications compared with pure VO2 based Materials and previously reported Thermochromic hybrids.

  • tungsten doped vo2 microgels hybrid Thermochromic Material and its smart window application
    RSC Advances, 2017
    Co-Authors: Yong Sheng Yang, Freddy Boey Yin Chiang, Yang Zhou, Yi Long
    Abstract:

    Thermal sensitive microgels were synthesized directly from hydroxypropyl cellulose (HPC) and acrylic acid (AA) in pure water. The first cloud point temperature, near 45 °C, of the inorganic/organic hybrid Thermochromic Material was obtained by dispersing W doped VO2 in HPCA microgels and the composite microgel is highly transparent at room temperature with Tlum = 80% when the thickness is 25 μm. The excellent solar modulating ability (ΔTsol) of 36%, high averaged Tlum of 56% and relatively high cloud point temperature of 50 °C make it suitable for smart windows applications compared with pure VO2 based Materials and previously reported Thermochromic hybrids.

  • temperature responsive hydroxypropylcellulose based Thermochromic Material and its smart window application
    RSC Advances, 2016
    Co-Authors: Yong Sheng Yang, Freddy Boey Yin Chiang, Yang Zhou, Yi Long
    Abstract:

    Thermochromic Materials are the most cost effective smart window Materials and the organic hydrogel Material has large solar modulating ability (ΔTsol) and the luminous transmittance (Tlum) compared with inorganic VO2 based Materials. Here we report a green and new organic Thermochromic Material based on hydroxypropylcellulose. With increasing addition of NaCl from 0.5% (wt%) to 5% (wt%), the LCST (lower critical solution temperature) could reduce from 42 °C to 30 °C. The morphology change of freeze dried samples below and above LCST proves that the phase change of this hydroxypropylcellulose based hydrogel is due to the solubility change of the polymer in water. The fine-tuned recipe can give an outstanding solar modulating ability (ΔTsol) of 25.7% and high averaged Tlum of 67.4% with LCST of 38 °C.

  • terbium doped vo2 thin films reduced phase transition temperature and largely enhanced luminous transmittance
    Langmuir, 2016
    Co-Authors: Ning Wang, Martial Duchamp, Rafal E Duninborkowski, Xianting Zeng, Yi Long
    Abstract:

    Vanadium dioxide (VO2) is a well-known Thermochromic Material with large IR modulating ability, promising for energy-saving smart windows. The main drawbacks of VO2 are its high phase transition temperature (τc = 68 °C), low luminous transmission (Tlum), and weak solar modulating ability (ΔTsol). In this paper, the terbium cation (Tb3+) doping was first reported to reduce τc and increase Tlum of VO2 thin films. Compared with pristine VO2, 2 at. % doping level gives both enhanced Tlum and ΔTsol from 45.8% to 54.0% and 7.7% to 8.3%, respectively. The Tlum increases with continuous Tb3+ doping and reaches 79.4% at 6 at. % doping level, representing ∼73.4% relative increment compared with pure VO2. This has surpassed the best reported doped VO2 thin films. The enhanced Thermochromic properties is meaningful for smart window applications of VO2 Materials.

Yang Zhou - One of the best experts on this subject based on the ideXlab platform.

  • Index-tunable anti-reflection coatings: Maximizing solar modulation ability for vanadium dioxide-based smart Thermochromic glazing
    Journal of Alloys and Compounds, 2018
    Co-Authors: Chang Liu, Schlomo Magdassi, Chor Yong Tay, Shancheng Wang, Daniel Mandler, Qi Lu, Haibo Yang, Yang Zhou, Yi Long
    Abstract:

    Vanadium dioxide (VO2) nanoparticles with reversible semiconductor-metal phase transition holds the tremendous potential as a Thermochromic Material for the energy-saving smart glazing. However, the trade-off between improving the luminous transmittance (Tlum) while sacrificing the solar modulation ability (ΔTsol) hampers its bench-to-market translation. Previous studies of anti-reflection coatings (ARCs) focused primarily on increasing Tlumwhile neglecting ΔTsol, which is a key energy-saving determinant. The intrinsically low ΔTsol(

  • Tungsten doped VO2/microgels hybrid Thermochromic Material and its smart window application
    RSC Advances, 2017
    Co-Authors: Yong Sheng Yang, Freddy Boey Yin Chiang, Yang Zhou, Yi Long
    Abstract:

    Thermal sensitive microgels were synthesized directly from hydroxypropyl cellulose (HPC) and acrylic acid (AA) in pure water. The first cloud point temperature, near 45 °C, of the inorganic/organic hybrid Thermochromic Material was obtained by dispersing W doped VO2 in HPCA microgels and the composite microgel is highly transparent at room temperature with Tlum = 80% when the thickness is 25 μm. The excellent solar modulating ability (ΔTsol) of 36%, high averaged Tlum of 56% and relatively high cloud point temperature of 50 °C make it suitable for smart windows applications compared with pure VO2 based Materials and previously reported Thermochromic hybrids.

  • tungsten doped vo2 microgels hybrid Thermochromic Material and its smart window application
    RSC Advances, 2017
    Co-Authors: Yong Sheng Yang, Freddy Boey Yin Chiang, Yang Zhou, Yi Long
    Abstract:

    Thermal sensitive microgels were synthesized directly from hydroxypropyl cellulose (HPC) and acrylic acid (AA) in pure water. The first cloud point temperature, near 45 °C, of the inorganic/organic hybrid Thermochromic Material was obtained by dispersing W doped VO2 in HPCA microgels and the composite microgel is highly transparent at room temperature with Tlum = 80% when the thickness is 25 μm. The excellent solar modulating ability (ΔTsol) of 36%, high averaged Tlum of 56% and relatively high cloud point temperature of 50 °C make it suitable for smart windows applications compared with pure VO2 based Materials and previously reported Thermochromic hybrids.

  • temperature responsive hydroxypropylcellulose based Thermochromic Material and its smart window application
    RSC Advances, 2016
    Co-Authors: Yong Sheng Yang, Freddy Boey Yin Chiang, Yang Zhou, Yi Long
    Abstract:

    Thermochromic Materials are the most cost effective smart window Materials and the organic hydrogel Material has large solar modulating ability (ΔTsol) and the luminous transmittance (Tlum) compared with inorganic VO2 based Materials. Here we report a green and new organic Thermochromic Material based on hydroxypropylcellulose. With increasing addition of NaCl from 0.5% (wt%) to 5% (wt%), the LCST (lower critical solution temperature) could reduce from 42 °C to 30 °C. The morphology change of freeze dried samples below and above LCST proves that the phase change of this hydroxypropylcellulose based hydrogel is due to the solubility change of the polymer in water. The fine-tuned recipe can give an outstanding solar modulating ability (ΔTsol) of 25.7% and high averaged Tlum of 67.4% with LCST of 38 °C.

  • Temperature-responsive hydroxypropylcellulose based Thermochromic Material and its smart window application
    RSC Adv., 2016
    Co-Authors: Yong Sheng Yang, Freddy Boey Yin Chiang, Freddy Boey Yin Chiang, Yang Zhou, Yi Long
    Abstract:

    Thermochromic Materials are the most cost effective smart window Materials and the organic hydrogel Material has large solar modulating ability (Δ T sol ) and the luminous transmittance ( T lum ) compared with inorganic VO 2 based Materials.

Yimin Xuan - One of the best experts on this subject based on the ideXlab platform.

  • radiative properties of Thermochromic Material with solar reflection films
    Solar Energy Materials and Solar Cells, 2013
    Co-Authors: Qiang Li, Yimin Xuan, Junfei Fang
    Abstract:

    Abstract Thermochromic Material La 0.7 Ca 0.2 Sr 0.1 MnO 3 is synthesized by solid-state reaction method. The solar absorptance, thermal emittance and reflectance are investigated. The research results indicated that the Material has such a large solar absorptance value of 0.78 that it is disadvantageous for the thermal control Material in space. Within the 97–373 K range, the thermal emittance of the Material increases with the rise of temperature, and its variation amplitude is 0.6. To reduce the high solar absorptance and keep the variation amplitude of the emittance, solar reflection films are deposited onto the surface of the Material. Experimental results show that the solar absorptance is reduced from the 0.78 of bare Thermochromic Material to the 0.27 of Thermochromic Material with solar reflection films, and the variation amplitude of the emittance is not affected by the films. In addition, irradiation suitability study of the Material with solar reflection films for space application suggests that the variable emittance properties have no degradation undergoing the electrons and protons irradiation.

  • tailoring the solar absorptivity of Thermochromic Material la0 7ca0 2sr0 1mno3
    Journal of Quantitative Spectroscopy & Radiative Transfer, 2011
    Co-Authors: Qiang Li, Yimin Xuan
    Abstract:

    Abstract La 0.7 Ca 0.2 Sr 0.1 MnO 3 is a Thermochromic Material which can be used as thermal control device. However, its solar absorptivity is too high for that in spacecraft application. To reduce its solar absorptivity, an optical thin film is designed in this paper by using simulated annealing genetic algorithm. This film can effectively reflect the solar radiation at the short wave and can be transparent at long wave. A designed optical thin film is deposited on the surface of Thermochromic Material by electron beam evaporation. Experiments show that the solar absorptivity is reduced from 0.78 to 0.28 at short wave, and the transmissivity is 0.87 at long wave. The results match pretty well with the theoretical predictions in a global view.

  • Emissivity and Optical Properties of Thermochromic Material La0.7Ca0.3−xSrxMnO3 (0 ≤ x ≤ 0.3)
    International Journal of Thermophysics, 2011
    Co-Authors: Qiang Li, Yimin Xuan
    Abstract:

    La0.7Ca0.3−xSrxMnO3 (0 ≤ x ≤ 0.3) (LCSMO) is a Thermochromic Material. The Material can show a phase transition from ferromagnetic-metal to paramagnetic-insulator under the appropriate doping level (x). In this paper, LCSMO compounds were synthesized by a conventional solid-state reaction method. The normal emissivity and the spectral reflectance of LCSMO with different doping levels (x) are experimentally investigated. Based on the spectral reflectance data, the optical constants (refractive index n and extinction coefficient k) are calculated by using Kramers–Kronig (K–K) relations. Then, the emissivity changing mechanism is discussed. The experimental results show that the emissivity of LCSMO increases with increasing temperature. For the samples with x = 0.1 and 0.15, their emissivity has a sudden change in the vicinity of the phase transition temperature Tp.

  • emissivity and optical properties of Thermochromic Material la0 7ca0 3 xsrxmno3 0 x 0 3
    International Journal of Thermophysics, 2011
    Co-Authors: Qiang Li, Yimin Xuan
    Abstract:

    La0.7Ca0.3−xSrxMnO3 (0 ≤ x ≤ 0.3) (LCSMO) is a Thermochromic Material. The Material can show a phase transition from ferromagnetic-metal to paramagnetic-insulator under the appropriate doping level (x). In this paper, LCSMO compounds were synthesized by a conventional solid-state reaction method. The normal emissivity and the spectral reflectance of LCSMO with different doping levels (x) are experimentally investigated. Based on the spectral reflectance data, the optical constants (refractive index n and extinction coefficient k) are calculated by using Kramers–Kronig (K–K) relations. Then, the emissivity changing mechanism is discussed. The experimental results show that the emissivity of LCSMO increases with increasing temperature. For the samples with x = 0.1 and 0.15, their emissivity has a sudden change in the vicinity of the phase transition temperature Tp.

  • Tailoring the solar absorptivity of Thermochromic Material La0.7Ca0.2Sr0.1MnO3
    Journal of Quantitative Spectroscopy and Radiative Transfer, 2011
    Co-Authors: Desong Fan, Qiang Li, Yimin Xuan
    Abstract:

    La0.7Ca0.2Sr0.1MnO3 is a Thermochromic Material which can be used as thermal control device. However, its solar absorptivity is too high for that in spacecraft application. To reduce its solar absorptivity, an optical thin film is designed in this paper by using simulated annealing genetic algorithm. This film can effectively reflect the solar radiation at the short wave and can be transparent at long wave. A designed optical thin film is deposited on the surface of Thermochromic Material by electron beam evaporation. Experiments show that the solar absorptivity is reduced from 0.78 to 0.28 at short wave, and the transmissivity is 0.87 at long wave. The results match pretty well with the theoretical predictions in a global view. © 2011 Elsevier Ltd.

Yong Sheng Yang - One of the best experts on this subject based on the ideXlab platform.

  • Tungsten doped VO2/microgels hybrid Thermochromic Material and its smart window application
    RSC Advances, 2017
    Co-Authors: Yong Sheng Yang, Freddy Boey Yin Chiang, Yang Zhou, Yi Long
    Abstract:

    Thermal sensitive microgels were synthesized directly from hydroxypropyl cellulose (HPC) and acrylic acid (AA) in pure water. The first cloud point temperature, near 45 °C, of the inorganic/organic hybrid Thermochromic Material was obtained by dispersing W doped VO2 in HPCA microgels and the composite microgel is highly transparent at room temperature with Tlum = 80% when the thickness is 25 μm. The excellent solar modulating ability (ΔTsol) of 36%, high averaged Tlum of 56% and relatively high cloud point temperature of 50 °C make it suitable for smart windows applications compared with pure VO2 based Materials and previously reported Thermochromic hybrids.

  • tungsten doped vo2 microgels hybrid Thermochromic Material and its smart window application
    RSC Advances, 2017
    Co-Authors: Yong Sheng Yang, Freddy Boey Yin Chiang, Yang Zhou, Yi Long
    Abstract:

    Thermal sensitive microgels were synthesized directly from hydroxypropyl cellulose (HPC) and acrylic acid (AA) in pure water. The first cloud point temperature, near 45 °C, of the inorganic/organic hybrid Thermochromic Material was obtained by dispersing W doped VO2 in HPCA microgels and the composite microgel is highly transparent at room temperature with Tlum = 80% when the thickness is 25 μm. The excellent solar modulating ability (ΔTsol) of 36%, high averaged Tlum of 56% and relatively high cloud point temperature of 50 °C make it suitable for smart windows applications compared with pure VO2 based Materials and previously reported Thermochromic hybrids.

  • temperature responsive hydroxypropylcellulose based Thermochromic Material and its smart window application
    RSC Advances, 2016
    Co-Authors: Yong Sheng Yang, Freddy Boey Yin Chiang, Yang Zhou, Yi Long
    Abstract:

    Thermochromic Materials are the most cost effective smart window Materials and the organic hydrogel Material has large solar modulating ability (ΔTsol) and the luminous transmittance (Tlum) compared with inorganic VO2 based Materials. Here we report a green and new organic Thermochromic Material based on hydroxypropylcellulose. With increasing addition of NaCl from 0.5% (wt%) to 5% (wt%), the LCST (lower critical solution temperature) could reduce from 42 °C to 30 °C. The morphology change of freeze dried samples below and above LCST proves that the phase change of this hydroxypropylcellulose based hydrogel is due to the solubility change of the polymer in water. The fine-tuned recipe can give an outstanding solar modulating ability (ΔTsol) of 25.7% and high averaged Tlum of 67.4% with LCST of 38 °C.

  • Temperature-responsive hydroxypropylcellulose based Thermochromic Material and its smart window application
    RSC Adv., 2016
    Co-Authors: Yong Sheng Yang, Freddy Boey Yin Chiang, Freddy Boey Yin Chiang, Yang Zhou, Yi Long
    Abstract:

    Thermochromic Materials are the most cost effective smart window Materials and the organic hydrogel Material has large solar modulating ability (Δ T sol ) and the luminous transmittance ( T lum ) compared with inorganic VO 2 based Materials.

Qiang Li - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of cooling effect and pavement performance for Thermochromic Material modified asphalt mixtures under solar radiation
    Construction and Building Materials, 2020
    Co-Authors: Qiang Li, Tingyu Hu, Chaohui Wang, Yongsheng Guan
    Abstract:

    Abstract The thermal effect of asphalt pavements on the surrounding environment in summer is of increasing concern since they absorb a great deal of heat from solar radiation and contribute greatly to the urban heat island effect. A novel Thermochromic Material modified asphalt binder is proposed to modulate pavement temperature by reversibly changing colors and reflectivity to solar radiation in response to temperature variations. In this study, an attempt is extended into the mixture scale. The cooling effect and pavement performance of Thermochromic Material modified asphalt mixtures are evaluated using a proposed solar radiation simulation test and various mechanical tests. The Thermochromic Material modification mechanism is revealed from the physical and chemical points of view. It is found that the addition of Thermochromic additive to base binders has a significant cooling effect on asphalt pavements in summer. The maximum temperature reduction is observed at the bottom of the top asphalt layer and the top of the middle asphalt layer. Two types of Thermochromic additives show positive and negative effects on rutting resistance. Thermochromic Material modification has little effect on low-temperature cracking resistance and all Thermochromic Material modified mixtures exhibit good moisture stability. Preliminary recommendations on the optimum additive type and content of Thermochromic Material are proposed. The characteristics of coating, dispersion, and intactness of Thermochromic additives in base binders significantly affect the pavement performance of asphalt mixtures. The particle size of the Thermochromic additive and the chemical composition of shell Material are critical to binder modification.

  • radiative properties of Thermochromic Material with solar reflection films
    Solar Energy Materials and Solar Cells, 2013
    Co-Authors: Qiang Li, Yimin Xuan, Junfei Fang
    Abstract:

    Abstract Thermochromic Material La 0.7 Ca 0.2 Sr 0.1 MnO 3 is synthesized by solid-state reaction method. The solar absorptance, thermal emittance and reflectance are investigated. The research results indicated that the Material has such a large solar absorptance value of 0.78 that it is disadvantageous for the thermal control Material in space. Within the 97–373 K range, the thermal emittance of the Material increases with the rise of temperature, and its variation amplitude is 0.6. To reduce the high solar absorptance and keep the variation amplitude of the emittance, solar reflection films are deposited onto the surface of the Material. Experimental results show that the solar absorptance is reduced from the 0.78 of bare Thermochromic Material to the 0.27 of Thermochromic Material with solar reflection films, and the variation amplitude of the emittance is not affected by the films. In addition, irradiation suitability study of the Material with solar reflection films for space application suggests that the variable emittance properties have no degradation undergoing the electrons and protons irradiation.

  • tailoring the solar absorptivity of Thermochromic Material la0 7ca0 2sr0 1mno3
    Journal of Quantitative Spectroscopy & Radiative Transfer, 2011
    Co-Authors: Qiang Li, Yimin Xuan
    Abstract:

    Abstract La 0.7 Ca 0.2 Sr 0.1 MnO 3 is a Thermochromic Material which can be used as thermal control device. However, its solar absorptivity is too high for that in spacecraft application. To reduce its solar absorptivity, an optical thin film is designed in this paper by using simulated annealing genetic algorithm. This film can effectively reflect the solar radiation at the short wave and can be transparent at long wave. A designed optical thin film is deposited on the surface of Thermochromic Material by electron beam evaporation. Experiments show that the solar absorptivity is reduced from 0.78 to 0.28 at short wave, and the transmissivity is 0.87 at long wave. The results match pretty well with the theoretical predictions in a global view.

  • Emissivity and Optical Properties of Thermochromic Material La0.7Ca0.3−xSrxMnO3 (0 ≤ x ≤ 0.3)
    International Journal of Thermophysics, 2011
    Co-Authors: Qiang Li, Yimin Xuan
    Abstract:

    La0.7Ca0.3−xSrxMnO3 (0 ≤ x ≤ 0.3) (LCSMO) is a Thermochromic Material. The Material can show a phase transition from ferromagnetic-metal to paramagnetic-insulator under the appropriate doping level (x). In this paper, LCSMO compounds were synthesized by a conventional solid-state reaction method. The normal emissivity and the spectral reflectance of LCSMO with different doping levels (x) are experimentally investigated. Based on the spectral reflectance data, the optical constants (refractive index n and extinction coefficient k) are calculated by using Kramers–Kronig (K–K) relations. Then, the emissivity changing mechanism is discussed. The experimental results show that the emissivity of LCSMO increases with increasing temperature. For the samples with x = 0.1 and 0.15, their emissivity has a sudden change in the vicinity of the phase transition temperature Tp.

  • emissivity and optical properties of Thermochromic Material la0 7ca0 3 xsrxmno3 0 x 0 3
    International Journal of Thermophysics, 2011
    Co-Authors: Qiang Li, Yimin Xuan
    Abstract:

    La0.7Ca0.3−xSrxMnO3 (0 ≤ x ≤ 0.3) (LCSMO) is a Thermochromic Material. The Material can show a phase transition from ferromagnetic-metal to paramagnetic-insulator under the appropriate doping level (x). In this paper, LCSMO compounds were synthesized by a conventional solid-state reaction method. The normal emissivity and the spectral reflectance of LCSMO with different doping levels (x) are experimentally investigated. Based on the spectral reflectance data, the optical constants (refractive index n and extinction coefficient k) are calculated by using Kramers–Kronig (K–K) relations. Then, the emissivity changing mechanism is discussed. The experimental results show that the emissivity of LCSMO increases with increasing temperature. For the samples with x = 0.1 and 0.15, their emissivity has a sudden change in the vicinity of the phase transition temperature Tp.