scholarly journals Microstructure and Thermal Insulation Property of Silica Composite Aerogel

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 993 ◽  
Author(s):  
Lei Shang ◽  
Yang Lyu ◽  
Wenbo Han
Keyword(s):  
Thermal Insulation ◽  
Silica Aerogel ◽  
Infrared Radiation ◽  
Performance Test ◽  
Heat Insulation ◽  
Insulation Material ◽  
Cold Surface ◽  
Composite Aerogel ◽  
Aerogel Composite ◽  
Insulation Performance

Tetraethyl orthosilicate was selected as a matrix of heat insulating materials among three silanes, and an anti-infrared radiation fiber was chosen as a reinforcement for silica aerogel insulation composite. The silica aerogel was combined well and evenly distributed in the anti-infrared radiation fiber. The heat insulation effect was improved with the increase in thickness of the aerogel insulation material, as determined by the self-made aerospace insulation material insulation performance test equipment. The 15 mm and 30 mm thick thermal insulation material heated at 250 °C for 3 h, the temperatures at the cold surface were about 80 °C and 60 °C, respectively, and the temperatures at 150 mm above the cold surface were less than 60 °C and 50 °C, respectively. The silica aerogel composites with various thicknesses showed good thermal insulation stability. The silica insulation composite with a thickness of 15 mm exhibited good heat insulation performance, meets the thermal insulation requirements of general equipment compartments under low-temperature and long-term environmental conditions. The thermal conductivity of prepared silica aerogel composite was 0.0191 W·m−1·k−1 at room temperature and 0.0489 W·m−1·k−1 at 500 °C.

scholarly journals Cost-Effective Additive Manufacturing of Ambient Pressure-dried Silica Aerogel

2020 ◽  
pp. 1-32
Author(s):  
Zipeng Guo ◽  
Ruizhe Yang ◽  
Tianjiao Wang ◽  
Lu An ◽  
Shenqiang Ren ◽  
...  
Keyword(s):  
Thermal Insulation ◽  
Silica Aerogel ◽  
Processing Time ◽  
Ambient Pressure ◽  
Cost Effective ◽  
Supercritical Drying ◽  
Insulation Material ◽  
Market Demand ◽  
Insulation Property ◽  
Insulation Performance

Abstract The conventional manufacturing processes of aerogel insulation material is largely relying on the supercritical drying, which suffers from issues of massive energy consumption, high-cost equipment, and prolonged processing time. With the consideration of large market demand of the aerogel insulation material in the next decade, a low-cost and scalable fabrication technique is highly desired. In this paper, a direct ink writing (DIW) method is used to three-dimensionally fabricate the silica aerogel insulation material, followed by room-temperature and ambient pressure drying. Compared to the supercritical drying and freeze-drying, the reported method significantly reduces the fabrication time and costs. The cost-effective DIW technique offers the capability to print complex hollow internal structures, coupled with the porous structure, is found to be beneficial to the thermal insulation property. The addition of fiber to the ink assures the durability of the fabricated product, without sacrificing the thermal insulation performance. The foam ink preparation methods and the printability are demonstrated in this paper, along with the printing of complex three-dimensional geometries. The thermal insulation performance of the printed objects is characterized, and the mechanical properties are also examined. The proposed approach is found to have 56% reduction in the processing time. The printed silica aerogels exhibit a low thermal conductivity of 0.053 W m−1 K−1.

Thermal insulation performance of silicone rubber / silica aerogel composite

2021 ◽  
pp. 125359
Author(s):  
Zulhelmi Alif Abd Halim ◽  
Norhayati Ahmad ◽  
M. Azizi M. Yajid ◽  
Halimaton Hamdan
Keyword(s):  
Thermal Insulation ◽  
Silicone Rubber ◽  
Silica Aerogel ◽  
Aerogel Composite ◽  
Insulation Performance

scholarly journals Influence of Far Infrared TiO2 and Multi-Walled Carbon Nanotubes Coatings on the Performance of a Hot Water Heater

2021 ◽  
Vol 11 (15) ◽  
pp. 7043
Author(s):  
Tun-Ping Teng ◽  
Shang-Pang Yu ◽  
Yeou-Feng Lue ◽  
Qi-Lin Xie ◽  
Hsiang-Kai Hsieh ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Heating Rate ◽  
Heat Insulation ◽  
Far Infrared ◽  
Hot Water ◽  
Insulation Material ◽  
Water Heater ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Insulation Performance

This study selects titanium dioxide (TiO2) and multi-walled carbon nanotubes (MWCNTs) as far-infrared materials (FIRMs), and further adds water-based acrylic coatings to prepare far-infrared coatings (FIRCs). FIRCs are uniformly coated on #304 stainless steel sheets to make the test samples, which are then installed between the shell and insulation material of the hot water heater to measure the influences of various FIRCs on the performance of the hot water heater. The research results show no significant difference in the heating rate or heat insulation performance of the hot water heater with or without FIRCs coating. However, the uniformity of the water temperatures of the test samples is significantly improved with FIRCs. Considering that the uniformity of water temperature will inhibit the heating rate and heat insulation performance of the hot water heater, TiO2-FIRC should provide better performance improvement when applied to the hot water heater in this study. The application of TiO2-FIRC to large-scale hot water heaters with a high aspect ratio will effectively improve the quality of hot water supply in the future.

Preparation and Properties of Phase Change Thermal Insulation Materials

2018 ◽  
Vol 281 ◽  
pp. 131-136
Author(s):  
Shi Chao Zhang ◽  
Wei Wu ◽  
Yu Feng Chen ◽  
Liu Shi Tao ◽  
Kai Fang ◽  
...  
Keyword(s):  
Phase Change ◽  
Thermal Insulation ◽  
Calcium Silicate ◽  
Phase Change Materials ◽  
Performance Test ◽  
Thermal Protection ◽  
Insulation Material ◽  
Insulation Materials ◽  
Short Time ◽  
Change Material

With the increase of the speed of vehicle, the thermal protection system of its powerplant requires higher insulation materials. Phase change materials can absorb large amounts of heat in short time. So the introduction of phase change materials in thermal insulation materials can achieve efficient insulation in a limited space for a short time. In this paper, a new phase change thermal insulation material was prepared by pressure molding with microporous calcium silicate as matrix and Li2CO3 as phase change material. The morphology stability, exudation and heat insulation of the materials were tested. The results show that the porous structure of microporous calcium silicate has a good encapsulation when the phase transition of Li2CO3 is changed into liquid. And the material has no leakage during use. The thermal performance test also shows that the insulation performance of the material has obvious advantages in the short term application.

Lightweight, Flexible and Hydrophobic Cotton Fiber/Silica Aerogel Composite by Freeze-Drying for Organic Solvent/Water Separation and Thermal Insulation

2021 ◽  
Vol 13 (9) ◽  
pp. 1820-1824
Author(s):  
Jian-Chun Huo ◽  
Hai-Xia Yang ◽  
Yuan Ma ◽  
Jie Bai
Keyword(s):  
Thermal Insulation ◽  
Cotton Fiber ◽  
Silica Aerogel ◽  
Low Cost ◽  
Sol Gel ◽  
Water Separation ◽  
Organic Reagents ◽  
Strong Adsorption ◽  
Aerogel Composite ◽  
Oil Water Separation

Natural cotton fiber used for reinforcement is low-cost, environmentally friendly, good flexibility and easy to obtain. In this study, a new cotton fiber/silica aerogel composite was developed by sol–gel method via freezedrying. The obtained composite has excellent flexibility and can be restored to its original state after bending for 180° without obvious cracks. After 20 cycles continuous compression, the total unrecoverable strain loss is only 20% under strain of 60%. The composite also shows very prominent hydrophobicity, and the contact angle with water reaches 145 degrees. It has strong adsorption capacity for organic reagents and oil, with adsorption ratios of 500% and 600%, respectively. In addition, the composite has a low thermal conductivity of 0.038 W/(m·K) at room temperature. The obtained composite exhibits considerable promise in oil-water separation and thermal insulation.

Enhancement of Mechanical and Thermal Characteristics of Polyurethane-Based Composite with Silica Aerogel

2019 ◽  
Vol 951 ◽  
pp. 63-67 ◽  
Author(s):  
Jae Hyeok Ahn ◽  
Jeong Hyeon Kim ◽  
Jeong Dae Kim ◽  
Seul Kee Kim ◽  
Kang Hyun Park ◽  
...  
Keyword(s):  
Silica Aerogel ◽  
Heat Insulation ◽  
Porous Silica ◽  
Thermal Characteristics ◽  
Weight Percent ◽  
Polyurethane Foams ◽  
Mechanical And Thermal Properties ◽  
Efficient Alternative ◽  
Insulation Performance ◽  
Compressive Tests

Synthesis of polyurethane foams (PUF) with silica aerogel nanoparticles is an efficient alternative to improve the mechanical and thermal properties of the foam owing to the outstanding thermal insulation properties of porous silica aerogel nanoparticles. Silica aerogel was added into polyurethane foams at different weight percent (0, 1, 3, 5 wt.%) to observe the changes in the material properties. To confirm the applicability of the synthesized PUF to the heat insulating material, compressive tests were carried out at ambient and cryogenic temperature (20, -163°C) and the thermal conductivities were measured according to wt.%. In addition, the cell microstructure was identified using FE-SEM to analyze the effect of silica aerogels on the foam morphologies. As a result of the experiment, it was confirmed that the mechanical strength and the heat insulation performance were improved in the polyurethane foam containing 1 wt.% of silica aerogel.

Performance of Thermal Insulation Reflective Composite Coatings

2011 ◽  
Vol 239-242 ◽  
pp. 1771-1774 ◽  
Author(s):  
Meng Qiu Jia ◽  
Yu Hong Jin
Keyword(s):  
Aqueous Solution ◽  
Thermal Insulation ◽  
Heat Insulation ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Insulation Property ◽  
Corrosion Properties ◽  
Rutile Titanium Dioxide ◽  
Insulation Performance ◽  
Good Heat

Reflective topcoat and thermal insulation mid-coat composite coatings system was used in this work. The effect of the content of the hollow glass micro-beads and rutile titanium dioxide on the heat insulation performance and the reflectivity of the coatings were investigated, respectively. The heat insulation performance and the reflectivity of the thermal insulation reflective composite coatings (TIRCCs) were characterized by self-prepared experimental device. The results showed the good heat insulation property, and the insulated temperature reached 12-15°C, and the reflectivity was up to 95%. The anti-corrosion and anti-penetration of the TIRCCs were studied by electrochemical impedance spectroscopy (EIS) technique. The results showed that the resistance of the TIRCCs still be maintained at 108Ω·cm2 after 30 days in the 3.5% aqueous solution of sodium chloride. So The TIRCCs can be used on the surface of the steal structure for decreasing the temperature and enhancing anti-corrosion properties.

Thermal Insulation Property of Newspaper Membrane Encased Soil-Based Aerated Lightweight Concrete Panels

2011 ◽  
Vol 261-263 ◽  
pp. 783-787 ◽  
Author(s):  
Soon Ching Ng ◽  
Kaw Sai Low ◽  
Ngee Heng Tioh
Keyword(s):  
Temperature Gradient ◽  
Thermal Insulation ◽  
Lightweight Concrete ◽  
Clayey Soil ◽  
Heat Insulation ◽  
Control Panel ◽  
Insulation Property ◽  
Concrete Panels ◽  
Thermal Insulation Property ◽  
Insulation Performance

Roof and wall are known to be responsible for heat entering into a building and should therefore be thermally insulated in order to lessen energy consumption required for air-conditioning. In this study, four soil-based aerated lightweight concrete (ALC) panels each measures 750 mm (length) x 750 mm (breadth) x 70 mm (thick) with different aerial intensity of newspaper membrane encased were produced and tested on their thermal insulation property. For environmental friendly and economy reasons, clayey soil was used in place of sand to produce the ALC panels and they were tested in the Thermal Laboratory for twenty hours. Temperature gradient was computed based on the surface temperature measured during the test. The results obtained indicated that newspaper membrane encased soil-based ALC panels have superior heat insulation performance compared to control panel in terms of temperature gradient. It is found that the temperature gradient increased from 1.92 °C/cm to 2.08 °C/cm or 8.3% higher than control panel with just merely 0.05 g/cm2 of newspaper membrane encased.

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