scholarly journals Improving anti-infrared radiation and heat insulation by potassium hexatitanate whisker-doped Al 2 O 3 –SiO 2 composite xerogel

2018 ◽  
Vol 5 (12) ◽  
pp. 180787
Author(s):  
Liang Furong ◽  
Liu Weijun ◽  
Han Xiuxiu ◽  
Zhang Boru ◽  
Zhang Shuhua
Keyword(s):  
Thermal Conductivity ◽  
Infrared Radiation ◽  
Near Infrared ◽  
Raw Materials ◽  
Sol Gel ◽  
Spectral Characteristics ◽  
Molar Ratio ◽  
Thermal Insulating ◽  
Infrared Spectral ◽  
Potassium Hexatitanate

Taking potassium hexatitanate whisker (PTW) modified by silane coupling agent KH550, aluminium nitrate inorganic salt and tetraethyl orthosilicate and deionized water, respectively, as infrared sunscreen, aluminium source and raw materials forming the network structure of a composite xerogel, a series of structurally intact PTW-doped Al 2 O 3 –SiO 2 composite xerogel thermal-insulating materials were prepared by the sol–gel method and dried under atmospheric pressure. The infrared spectral characteristics, infrared radiation transmittance, microstructures, morphology and thermal conductivity of different composite materials prepared have been determined by a Fourier transform infrared spectrometer, UV–visible–near-infrared spectrophotometer, X-ray diffractometer, scanning electron microscope and thermal conductivity tester. The results exhibit that when the Al to Si molar ratio is 1 : 9, the composite material with 5 wt% modified PTW shows the best infrared radiation blocking performance and the lowest thermal conductivity (0.0604 W m −1 K −1 ).

Sol-Gel Synthesis and Characterization of Ultrafine ZrSiO4 Powder

2014 ◽  
Vol 906 ◽  
pp. 66-71
Author(s):  
Zhen Quan Li ◽  
Qiang Zhen ◽  
Ya Li Wang
Keyword(s):  
Wavelength Range ◽  
High Purity ◽  
Raw Materials ◽  
Formation Rate ◽  
Sol Gel ◽  
Molar Ratio ◽  
Sem And Tem ◽  
Homogeneous Product ◽  
Sol Gel Synthesis ◽  
Calcined Temperature

High purity ZrSiO4 powder were synthesized using Si (C2H5O)4 and ZrOCl2·8H2O as raw materials by the sol-gel method, LiCl was added as mineralizer to promote crystallization of zircon. The influences of molar ratio of Zr:Si, calcined time and calcined temperature on the synthesis of ZrSiO4 powder were investigated. XRD, SEM and TEM were used to characterize the powders. It was found that when the molar ratio of Zr:Si was 1:1.2, the calcined temperature was 1600°C and the calcined time was 4h, the high purity ZrSiO4 ultrafine powder was obtained. The ZrSiO4 formation began at 1300°C and when the gel was calcined at 1600°Cfor 4 h, the formation rate of ZrSiO4 was up to 95%. SEM and TEM studies reveal a homogeneous product with particle sizes on the order of 0.1-1μm. The IR emissivity of ultrafine ZrSiO4 is 0.892 at the whole wavelength range, and that is up to 0.951 at the wavelength range of 8-14 μm.

Solar Reflection Characteristics of Phthalocyanine Green/TiO2 Composite Green Pigments Prepared via Different Approaches

2016 ◽  
Vol 849 ◽  
pp. 725-731 ◽  
Author(s):  
Xiao Juan Feng ◽  
Qian Jin Mao ◽  
Qiu Rui Lv ◽  
Zi Ming Wang ◽  
Su Ping Cui
Keyword(s):  
Near Infrared ◽  
Sol Gel ◽  
Coating Materials ◽  
Gel Method ◽  
Sol Gel Method ◽  
Reflective Coating ◽  
Study Results ◽  
Infrared Spectral ◽  
Physical Mixing ◽  
Green Pigments

Near-infrared pigment is the key to control the near-infrared performance of solar heat-reflective coating which has good economic and application prospects as a new special coating. Green infrared reflective pigments were prepared through physical mixing, inorganic lake method and sol-gel processes in this study. Results show that the near-infrared spectral reflectance of composite pigments is improved when using inorganic lake method and sol-gel method. Chromaticity of composite pigment is the closest to phthalocyanine green when using sol-gel method. Physically mixing method is not suitable to prepare infrared reflective pigment. The coating materials have influence on the coating effect and the reflectivity of near-infrared spectral range in a certain extent.

Synthesis Method and its Influence Factors of Hydrotalcite-Like Compounds

2013 ◽  
Vol 690-693 ◽  
pp. 351-354 ◽  
Author(s):  
Hong Dan Xue ◽  
Fu Li Wang ◽  
Guo Li Li ◽  
Pu Liu ◽  
Yong Qing Bai ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Reduction Method ◽  
Ph Value ◽  
Raw Materials ◽  
Sol Gel ◽  
Synthesis Method ◽  
Influence Factors ◽  
Synthetic Methods ◽  
Molar Ratio ◽  
Temperature Reaction

Hydrotalcite-like compounds are a class of anionic lays or layed double hydroxiods (LDHs) which consists of alkalescence, anion-exchanges and memory effect. The synthetic methods of LDHs include coprecipitation, hydrothermal synthesis, mirowave radiation, ion exchange, sol-gel method, roasting reduction method, instant synthesis, etc.The molar ratio of raw materials, pH value,reaction temperature,reaction time and so on have a greater impact on the purity and crystallinity of the LDHs.

scholarly journals Changes in Spectral Fluorescence Properties of a Near-Infrared Photosensitizer in a Nanoform as a Coating of an Optical Fiber Neuroport

Photonics ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 556
Author(s):  
Yuliya Maklygina ◽  
Igor Romanishkin ◽  
Aleksej Skobeltsin ◽  
Dina Farrakhova ◽  
Sergej Kharnas ◽  
...  
Keyword(s):  
Immune System ◽  
Spectral Region ◽  
Near Infrared ◽  
Fiber Optic ◽  
Spectral Characteristics ◽  
Infrared Spectral Region ◽  
Advanced Therapies ◽  
Infrared Spectral

In this work, we tested a new approach to assess the presence of inflammatory process in the implant area using spectral methods and the technique of fiber fluorescence analysis of photosensitizers in nanoform. First of all, the spectral characteristics of the photosensitizer when interacting with the porous surface of the implant, based on hydroxyapatite under in vitro and in vivo conditions, were determined. Thus, it was shown that spectral characteristics of photosensitizers can be used for judgement on the process of inflammation in the implant area and thus on the local presence of the immunocompetent cells. The analysis was performed at a sufficient depth in the biotissue by using the near-infrared spectral region, as well as two different methods: fiber-based laser spectroscopy and fiber-optic neuroscopy, which served to monitor the process and regular fluorescence diagnosis of the studied area. Fluorescence spectroscopic analysis was performed on experimental animals in vivo, i.e., under conditions of active immune system intervention, as well as on cell cultures in vitro in order to judge the role of the immune system in the interaction with the implant in comparison. Thus, the aim of the study was to determine the relationship between the fluorescence signal of nanophotosensitizers in the near infrared spectral region and its parameters with the level of inflammation and the type of surface with which the photosensitizer interacts in the implant area. Thus, fiber-optic control opens up new approaches for further diagnosis and therapy in the implant area, making immune cells a prime target for advanced therapies.

A Preliminary Study on the near Infrared Spectral Characteristics of Purchased Flue-Cured Tobacco

2011 ◽  
Vol 396-398 ◽  
pp. 2027-2032
Author(s):  
Ying Zhang ◽  
Li Yuan He
Keyword(s):  
Spectral Data ◽  
Near Infrared ◽  
Wave Length ◽  
Spectral Characteristics ◽  
Spectral Difference ◽  
Tobacco Leaf ◽  
Positive Group ◽  
Grade Classification ◽  
Infrared Spectral ◽  
Insignificant Difference

In order to explore the application of near-infrared spectrum technology in the grading of purchased flue-cured tobacco, positive group of flue-cured tobacco with different grades was gathered; the near-infrared spectral data across different grades, in the same grade, and different test zones of the same tobacco leaf were determined and acquired to analyze their near-infrared spectral characteristics and their representativeness. The findings indicated that the positive group of flue-cured tobacco was highly homogeneous; there was identical near-infrared spectral characteristics in any zone of the same tobacco leaf; the peaks and troughs of wave length of the near-infrared spectral characteristics of different samples with identical grade were also consistent, with extremely insignificant difference in reflectivity; the near-infrared spectral difference between the tobacco leaves with different grades was much more significant than that in different test zones of the same tobacco leaf. It was highly probable to take the reflectance ratio of the peaks and troughs of wave length as the standard for grade classification. It is feasible to appraise the quality of purchased flue-cured tobacco using near-infrared spectral data.

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