Novel nanoporous silica aerogel impregnated highly porous ceramics with low thermal conductivity and enhanced mechanical properties

2013 ◽  
Vol 68 (8) ◽  
pp. 599-602 ◽  
Author(s):  
Chang-Qing Hong ◽  
Jie-Cai Han ◽  
Xing-Hong Zhang ◽  
Jian-Cong Du
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Silica Aerogel ◽  
Porous Ceramics ◽  
Nanoporous Silica ◽  
Low Thermal Conductivity ◽  
Highly Porous

Preparation and Properties of SiC/Phenolic Resin for the Heat of LED

2016 ◽  
Vol 848 ◽  
pp. 454-459
Author(s):  
Cong Wu ◽  
Kang Zhao ◽  
Yu Fei Tang ◽  
Ji Yuan Ma
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Powder Metallurgy ◽  
Phenolic Resin ◽  
Bending Strength ◽  
Experimental Results ◽  
Low Thermal Conductivity ◽  
Industry Standard ◽  
Insulation Performance

In order to solve the problem that low thermal conductivity of the plastics for the heat of LED, SiC/Phenolic resin for the heat of LED were fabricated combining powder metallurgy. The effects of particles diameters, content and adding nanoparticles on thermal conductivity of the fabricated composites were investigated, the mechanical properties were also characterized. The experimental results showed that the materials were obtained, and the insulation performance of the fabricated SiC/Phenolic resin was higher than the industry standard one, the thermal conductivity reached 4.1W/(m·k)-1. And the bending strength of the fabricated composites was up to 68.11MPa. The problem of low thermal conductivity of the material is expected to be solved. In addition, it is meaningful for improving LED life.

scholarly journals Silica Aerogel Monoliths Derived from Silica Hydrosol with Various Surfactants

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3192 ◽  
Author(s):  
Dong Chen ◽  
Xiaodong Wang ◽  
Wenhui Ding ◽  
Wenbing Zou ◽  
Qiong Zhu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Silica Aerogel ◽  
Low Cost ◽  
Ambient Pressure ◽  
Silica Aerogels ◽  
Ambient Pressure Drying ◽  
Low Thermal Conductivity ◽  
Silica Hydrosol ◽  
High Production Cost

Owing to their ultra-low thermal conductivity, silica aerogels are promising thermal insulators; however, their extensive application is limited by their high production cost. Thus, scientists have started to explore low-cost and easy preparation processes of silica aerogels. In this work, a low-cost method was proposed to prepare silica aerogels with industrial silica hydrosol and a subsequent ambient pressure drying (APD) process. Various surfactants (cationic, amphoteric, or anionic) were added to avoid solvent exchange and surface modification during the APD process. The effects of various surfactants on the microstructure, thermal conductivity, and thermal stability of the silica aerogels were studied. The results showed that the silica aerogels prepared with a cationic or anionic surfactant have better thermal stability than that prepared with an amphoteric surfactant. After being heated at 600 °C, the silica aerogel prepared with a cationic surfactant showed the highest specific surface area of 131 m2∙g−1 and the lowest thermal conductivity of 0.038 W∙m−1∙K−1. The obtained low-cost silica aerogel with low thermal conductivity could be widely applied as a thermal insulator for building and industrial energy-saving applications.

scholarly journals Hemp-Straw Composites: Gluing Study and Multi-Physical Characterizations

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1199 ◽  
Author(s):  
Marie Viel ◽  
Florence Collet ◽  
Sylvie Prétot ◽  
Christophe Lanos
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Sustainable Development ◽  
Wheat Straw ◽  
Feasibility Study ◽  
Building Materials ◽  
Environmentally Friendly ◽  
Insulating Materials ◽  
Low Thermal Conductivity

In order to meet the requirement of sustainable development, building materials are increasingly environmentally friendly. They can be partially or fully bio-based or recycled. This paper looks at the development of fully bio-based composites where agro-resources are valued as bio-based aggregates (hemp) and as binding materials (wheat). In a previous work, a feasibility study simultaneously investigated the processing and ratio of wheat straw required to ensure a gluing effect. In this paper, three kinds of hemp-straw composites are selected and compared with a hemp-polysaccharides composite. The gluing effect is analyzed chemically and via SEM. The developed composites were characterized multi-physically. They showed sufficiently high mechanical properties to be used as insulating materials. Furthermore, they showed good thermal performances with a low thermal conductivity (67.9–69.0 mW/(m · K) at 23 ° C, dry).

Highly Porous Zirconia Ceramic Foams with Low Thermal Conductivity from Particle-Stabilized Foams

2016 ◽  
Vol 99 (11) ◽  
pp. 3512-3515 ◽  
Author(s):  
Wen-Long Huo ◽  
Xiao-Yan Zhang ◽  
Yu-Gu Chen ◽  
Yu-Ju Lu ◽  
Wen-Ting Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Zirconia Ceramic ◽  
Ceramic Foams ◽  
Low Thermal Conductivity ◽  
Porous Zirconia ◽  
Highly Porous
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