Nanostructure evolution of silica aerogels under rapid heating from 600 °C to 1300 °C via in-situ TEM observation

Cai, Huafei; Jiang, Yonggang; Qu, Chao; Zhang, Sizhao; Li, Liangjun; Feng, Jing

doi:10.1016/j.ceramint.2020.02.011

Cited by 49 publications

(28 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…1 The aerogel family finds its applications such as high-performance thermal insulators, catalyst supports, absorbents, and cosmic dust collectors, due to its special features such as low density, high porosity, and large surface area. 2,3 Among the wide variety of aerogels, the oxide aerogels are considered to be qualified for hightemperature applications owing to their desirable thermal stability [3][4][5][6] in aerobic environment. For instance, alumina aerogels have attracted vast attention for their ability to maintain the large surface area and mesopore structure up to 1000 • C. [7][8][9] Alumina aerogels can be synthesized by using aluminum alkoxides or inorganic aluminum salts as precursors.…”

Section: Introductionmentioning

confidence: 99%

Foreign element doping and thermal stability of alumina aerogels

Peng

Feng

et al. 2021

J Am Ceram Soc.

Self Cite

View full text Add to dashboard Cite

The addition of foreign elements is considered as an effective method to improve the thermal stability of alumina aerogels at a higher temperature. However, the location and stabilizing mechanism of the foreign elements in the alumina aerogel have not been carefully studied. In this work, Si or La was introduced into the network of alumina aerogels through a sol-gel strategy. The Si-doped alumina aerogel maintained high surface area (92 m 2 /g) and pore volume (0.572 cm 3 /g) even at 1300 • C. The dopants prevented α-Al 2 O 3 transformation at elevated temperatures (1200 • C-1300 • C). The distribution of foreign ions and their stabilizing mechanism were discussed in detail. The doped alumina aerogels reinforced by mullite fiber felt, with quite low density and thermal conductivity, can be used as high-temperature thermal insulations.

show abstract

Section: Introductionmentioning

confidence: 99%

Foreign element doping and thermal stability of alumina aerogels

Peng

Feng

et al. 2021

J Am Ceram Soc.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Recently, silica aerogels as ideal supports have been widely drawn a lot of interest in catalytic applications, because of their low density, large surface areas, uniform pore size, high chemical/thermal/ mechanical stability, and good adsorption capacity. [15,16] Especially, the amorphous slender skeleton and unique porous structure of silica aerogels effectively inhibit gaseous and solid heat conduction, which can be used up to 800 C. [17] When silica aerogels are used above 800 C, they will sinter and shrink, caused by pore collapse and particle agglomeration during the sintering process. [17,18] However, when heat temperature is below 600 C, the nanostructure of silica aerogels has no obvious change.…”

Section: Introductionmentioning

confidence: 99%

“…[15,16] Especially, the amorphous slender skeleton and unique porous structure of silica aerogels effectively inhibit gaseous and solid heat conduction, which can be used up to 800 C. [17] When silica aerogels are used above 800 C, they will sinter and shrink, caused by pore collapse and particle agglomeration during the sintering process. [17,18] However, when heat temperature is below 600 C, the nanostructure of silica aerogels has no obvious change. [19,20] Therefore, silica aerogels are ideal supports for catalytic materials.…”

Section: Introductionmentioning

confidence: 99%

Porous SiO₂ supported CuO as a promising catalyst on the thermal decomposition of ammonium perchlorate

Guo

Tian

et al. 2021

Applied Organom Chemis

View full text Add to dashboard Cite

Reducing the thermal decomposition temperature of ammonium perchlorate (AP) is of great significance for its application in composite solid propellants. Here, CuO/SiO 2 nanocomposites were prepared using wet impregnation method with Cu (CH 3 COO) 2 ÁH 2 O as copper precursor followed by a calcination process. The structure and morphology of the prepared samples were characterized with the help of scanning electron microscopy (SEM), Xray diffraction (XRD), and Brunauer-Emmett-Teller (BET), respectively. The outcomes revealed the uniform dispersion of CuO were throughout silica aerogels to prevent agglomeration efficiently. Moreover, results from differential scanning calorimeter (DSC) showed that CuO/SiO 2 nanocomposites could effectively enhance AP's thermal decomposition since they have large specific surface areas, many active reduction sites, and good adsorption capacity. As expected, the high decomposition temperature of AP was reduced from 418.7 C to 341.8 C when the amount of CuO/SiO 2 nanocomposites was 4 wt%. Therefore, silica aerogels were good catalyst supports of CuO for AP's thermal decomposition. It can bring about new potential for application of new materials in high energy as AP-based catalysts propellants which are solid in nature. K E Y W O R D Sammonium perchlorate, CuO/SiO 2 nanocomposites, silica aerogels, the thermal decomposition

show abstract

“…Aerogel, a kind of nano-porous material, exhibits excellent properties such as low density (Zhu et al, 2020), high specific area (Wu et al, 2017), high porosity (Li et al, 2019a;Zhao et al, 2020), and low thermal conductivity (Su et al, 2020), which receives great attention, becoming one of the most potential materials for the high-temperature thermal insulator in a thermal protection system. However, traditional SiO 2 aerogel cannot maintain its thermal stability in the long-time working temperature exceeding 800 °C (Cai et al, 2020). Though Al 2 O 3 aerogel shows improved thermal resistance, the metastable alumina phase converts to stable α-Al 2 O 3 after temperature over 1,050 °C and contributes to the collapse of the nano-porous structure and a considerable loss of surface area (Yang et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

Oxidation Resistance of Double-Layer MoSi2–Borosilicate Glass Coating on Fiber-Reinforced C/SiO2 Aerogel Composite

Dai

Zhang

et al. 2021

Front. Mater.

View full text Add to dashboard Cite

An MoSi2–borosilicate glass coating with high emissivity and oxidation resistance was prepared on the surface of the fiber-reinforced C/SiO2 aerogel composite by the slurry method combined with the embedding sintering method under the micro-oxygen atmosphere. The microstructure and phase composition of the coatings with different MoSi2 contents before and after static oxidation were investigated. This composite material has both excellent radiating properties and outstanding oxidation resistance. The total emissivity values of the as-prepared coatings are all above 0.8450 in the wavelength of 300∼2,500 nm. Meanwhile, the as-prepared M40 coating also has superior thermal endurance after the isothermal oxidation of 1,200°C for 180 min with only 0.27% weight loss, which contributes to the appropriate viscosity of the binder to relieve thermal stress defects. This material has broad application prospects in thermal protection.

show abstract

Nanostructure evolution of silica aerogels under rapid heating from 600 °C to 1300 °C via in-situ TEM observation

Cited by 49 publications

References 54 publications

Foreign element doping and thermal stability of alumina aerogels

Foreign element doping and thermal stability of alumina aerogels

Porous SiO₂ supported CuO as a promising catalyst on the thermal decomposition of ammonium perchlorate

Oxidation Resistance of Double-Layer MoSi2–Borosilicate Glass Coating on Fiber-Reinforced C/SiO2 Aerogel Composite

Contact Info

Product

Resources

About

Nanostructure evolution of silica aerogels under rapid heating from 600 °C to 1300 °C via in-situ TEM observation

Cited by 49 publications

References 54 publications

Foreign element doping and thermal stability of alumina aerogels

Foreign element doping and thermal stability of alumina aerogels

Porous SiO2 supported CuO as a promising catalyst on the thermal decomposition of ammonium perchlorate

Oxidation Resistance of Double-Layer MoSi2–Borosilicate Glass Coating on Fiber-Reinforced C/SiO2 Aerogel Composite

Contact Info

Product

Resources

About

Porous SiO₂ supported CuO as a promising catalyst on the thermal decomposition of ammonium perchlorate