Synthesis of high strength monolithic alumina aerogels at ambient pressure

RSC Advances ◽  
2015 ◽  
Vol 5 (23) ◽  
pp. 18025-18028 ◽  
Author(s):  
Fengchao Cao ◽  
Lili Ren ◽  
Xueai Li

Mechanically strong monolithic alumina aerogels were obtained via ambient pressure drying by incorporating attapulgite (ATP) and alumina sol.

2018 ◽  
Vol 13 (9) ◽  
pp. 1240-1244
Author(s):  
Chi Li ◽  
Zheng Gong ◽  
Likang Ding ◽  
Donglai Guo ◽  
Wenbin Hu

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3983
Author(s):  
Dongxuan Du ◽  
Fengqi Liu ◽  
Yonggang Jiang ◽  
Junzong Feng ◽  
Liangjun Li ◽  
...  

To further reduce the manufacturing cost and improve safety, silica aerogel composites (SAC) with low density and low thermal conductivity synthesized via ambient pressure drying (APD) technology have gradually become one of the most focused research areas. As a solvent, ethanol is flammable and needs to be replaced by other low surface tension solvents, which is dangerous and time-consuming. Therefore, the key steps of solvent replacement and surface modification in the APD process need to be simplified. Here, we demonstrate a facile strategy for preparing high strength mullite fiber reinforced SAC, which is synthesized by APD using water as a solvent, rather than using surface modification or solvent replacement. The effects of the fiber density on the physical properties, mechanical properties, and thermal conductivities of SAC are discussed in detail. The results show that when the fiber density of SAC is 0.24 g/cm3, the thermal conductivity at 1100 °C is 0.127 W/m·K, and the compressive strength at 10% strain is 1.348 MPa. Because of the simple synthesis process and excellent thermal-mechanical performance, the SAC is expected to be used as an efficient and economical insulation material.


Author(s):  
Guoqing Zu ◽  
Sheng Zeng ◽  
Ben Yang ◽  
Jia Huang

We report transparent, flexible, and superinsulating biocomposite aerogels with a homogeneous, highly porous, and nanofibrous structure based on oxidized starch and polyorganosiloxane via facile ambient pressure drying for the first time.


2017 ◽  
Vol 28 (12) ◽  
pp. 1945-1950 ◽  
Author(s):  
Ancy Smitha Alex ◽  
Ananda Lekshmi M.S. ◽  
Sekkar V. ◽  
Bibin John ◽  
Gouri C. ◽  
...  

2018 ◽  
Vol 86 (2) ◽  
pp. 479-492 ◽  
Author(s):  
Siqi Liu ◽  
Xiezhen Zhou ◽  
Weiqing Han ◽  
Jiansheng Li ◽  
Xiuyun Sun ◽  
...  

2010 ◽  
Vol 148-149 ◽  
pp. 1152-1162 ◽  
Author(s):  
Wen Zhi Zheng ◽  
Li Chen ◽  
Xiang Hua Huang ◽  
Lei Fu

Under microwave radiation and using trimethyl chlorosilane as modifier, hydrophobic SiO2 aerogel was prepared through fractional hydrophobic modification and ambient pressure drying of the raw material, tetraethoxysilane (TEOS), in the process of sol-gel and acid-base catalysis. Hydrophilic SiO2 aerogels were also prepared using the microwave method and water bath heating method. The SiO2 aerogels prepared using the three methods, including their morphology and chemical composition, were analyzed and compared using scanning electron microscopy, Brunauer-Emmett-Teller analysis method, Fourier transform infrared spectroscopy, X-ray diffraction, and themogravimetric-differential scanning calorimetry. The results indicate that by adopting the microwave reaction, the specific surface area of the SiO2 aerogels was effectively increased and the structure of the internal nanoscale pores of petal-coated shape was found to exist under the dense external surface of the SiO2 aerogels. Thermal stability of the hydrophobic SiO2 aerogels prepared through fractional modification assisted by the microwave method was increased with the hydrophobic angle at153°, which showed super hydrophobicity.


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