Preparation and Properties of Super Insulation Material SiO&lt;sub&gt;2&lt;/sub&gt; Aerogel

Ni, Xing Yuan; Wang, Ji Chao; Liu, Guang Wu; Zhang, Zhi Hua; Shen, Jun; Zhou, Bin; Wu, Guangcheng

doi:10.4028/www.scientific.net/amr.516-517.1531

Cited by 8 publications

(2 citation statements)

References 5 publications

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“…In view of this, the screening of catalysts was mainly focused on F-containing reagents since, like their compounds with metals/metalloids and others that are relatively strong LAs, the fluoride anion is a fairly strong base as it was mentioned in studies by Andrianov, Brinker, Pinnavaia and Prouzet, and Ni et al ,− As it turned out, of all the compounds that we used, a gel is formed from TMOS in an acetone solution only in the presence of AgBF 4 or SbF 3 : the wet gel formation time ( t w/g ) is 3 h (however, the gels formed are heterogeneous and contain a precipitate because of the low solubility of the catalysts in this system). In the case of HF, t w/g is 1.5 h, whereas in the presence of BF 3 ·Et 2 O, gels are formed in a record-short t w/g of 5–10 min (Table and Table S1, Supp.Inf.1).…”

Section: Resultsmentioning

confidence: 99%

Silica-Based Aerogels with Tunable Properties: The Highly Efficient BF₃-Catalyzed Preparation and Look inside Their Structure

et al. 2021

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This work presents a solution to one of the most fundamentally and practically important challenges in the production of silica-based aerogels, time consumption and expensiveness of these processes, with the main focus on the sol−gel process. We suggested a highly efficient BF 3 -catalyzed method for the production of aerogels, which allows one to shorten the stage of the formation of a (wet) gel to 5 min, the stage of gel aging to 0, while the stage of gel workup is not required; the duration of these stages, according to the literature, ranges from days to weeks. The process is performed using commercially available, simple, and inexpensive reagents and under mild reaction conditions: BF 3 •Et 2 O as the catalyst, acetone as the solvent, room temperature, and at atmospheric pressure. This approach allows one to quickly obtain both classic opaque and transparent silica-based aerogels from Si(OMe) 4 or Si(OEt) 4 as well as transparent superhydrophobic ones from their mixtures with MeSi(OMe) 3 or Me 2 Si(OMe) 2 . In addition, we succeeded in obtaining a series of aerogels with various organic and inorganic additives, in particular, in this way, luminescent and metallasiloxane ones were prepared. Also, the effect of the method for producing silica-based aerogels on their (supra)molecular structure and morphology was thoroughly studied by a set of physicochemical methods of analysis: scanning electron and light microscopy, X-ray microtomography, and NMR experiments. These findings allow to tune the density, transparency, mechanical strength, hydrophobicity, and other properties depending on the need by choosing the right technique.

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Section: Resultsmentioning

confidence: 99%

Silica-Based Aerogels with Tunable Properties: The Highly Efficient BF₃-Catalyzed Preparation and Look inside Their Structure

et al. 2021

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“…Aerogel is considered to be the solid material with the lowest thermal conductivity [1,2,3], among which SiO 2 aerogel is studied most comprehensively and has been applied in military, aeronautic and civil uses due to its thermal conductivity that can be as low as 0.013 W/(m·K) [4,5,6,7]. However, the effect of sintering is obvious when the usage temperature is over 1073 K, which leads to a serious degradation of the heat insulation property of the material [8,9,10].…”

Section: Introductionmentioning

confidence: 99%

Preparation and Properties of SiBCO Aerogel and Its Composites

Feng

Yin³

et al. 2018

Nanomaterials

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To obtain new high-temperature resistant composites that can meet the requirements of aircraft development for thermal insulation and mechanical properties, SiBCO aerogel composites were prepared by sol-gel, supercritical drying and high-temperature pyrolysis with trimethyl borate (TMB) or phenylboronic acid (PBA) as the boron source and mullite fiber as reinforcement. The structure and composition of the SiBCO aerogel and its composites were characterized with SEM, FT-IR, ICP and nitrogen adsorption tests. The specific surface area of the SiBCO aerogel is 293.22 m2/g, and the pore size is concentrated in the range of 10–150 nm. The mechanical properties, the thermal insulation properties and the temperature resistance were also studied. Due to the introduction of boron, the temperature resistance of SiBCO aerogel composites is improved greatly, and the service temperature of composites reached 1773 K. When n (TMB)/n (TEOS) = 1/1, the temperature resistance of the composites is the best. After heating in air at 1773 K for 30 min, the shrinkage of SiBCO aerogel composites is only 2.45%, and the thermal conductivity of the composites is 0.138 W/(m·K) at 1773 K. In addition, the type and amount of catalyst also have certain effects on the mechanical properties and temperature resistance of the composites.

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Iridescent structural color by using ultra-low refractive index aerogel as optical cavity dielectric

Paik,

Feng,

Clark

et al. 2024

Micro Nano Manuf.

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Iridescent color-shift pigments have been used in some industrial applications, e.g., for cosmetics and packaging. To achieve environmental-friendly and lasting color, thin-film interference is used to generate structural color. By maximizing the refractive index (RI) difference between the thin films (i.e., using an ultralow RI film), super-iridescent structural color can be produced. While the lowest refractive index of a naturally occurring solid dielectric is close to 1.37 (i.e., MgF2), we synthesized highly porous dielectric SiO2 aerogel to achieve ultralow-RI (n ~ 1.06) and demonstrated a high-refractive index/low-refractive index/absorber (HLA) trilayer structural color. The achieved structural color is highly iridescent and capable of tracing a near-closed loop in CIE color space. By tuning the refractive index, thickness, and geometry of the aerogel layer, we control the reflection dip’s shape, therefore producing a wide range of vivid and iridescent colors.

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Preparation and Properties of Super Insulation Material SiO<sub>2</sub> Aerogel

Cited by 8 publications

References 5 publications

Silica-Based Aerogels with Tunable Properties: The Highly Efficient BF₃-Catalyzed Preparation and Look inside Their Structure

Silica-Based Aerogels with Tunable Properties: The Highly Efficient BF₃-Catalyzed Preparation and Look inside Their Structure

Preparation and Properties of SiBCO Aerogel and Its Composites

Iridescent structural color by using ultra-low refractive index aerogel as optical cavity dielectric

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Preparation and Properties of Super Insulation Material SiO<sub>2</sub> Aerogel

Cited by 8 publications

References 5 publications

Silica-Based Aerogels with Tunable Properties: The Highly Efficient BF3-Catalyzed Preparation and Look inside Their Structure

Silica-Based Aerogels with Tunable Properties: The Highly Efficient BF3-Catalyzed Preparation and Look inside Their Structure

Preparation and Properties of SiBCO Aerogel and Its Composites

Iridescent structural color by using ultra-low refractive index aerogel as optical cavity dielectric

Contact Info

Product

Resources

About

Silica-Based Aerogels with Tunable Properties: The Highly Efficient BF₃-Catalyzed Preparation and Look inside Their Structure

Silica-Based Aerogels with Tunable Properties: The Highly Efficient BF₃-Catalyzed Preparation and Look inside Their Structure