Ambient Pressure Drying as an Advanced Approach to the Synthesis of Silica Aerogel Composite for Building Thermal Insulation

The article presents the synthesis of silica aerogel from a much cheaper precursor of water glass that was reinforced with short pitch carbon fiber by way of ambient pressure drying. Before being added to the silica gel, the carbon fibers were surface modified to increase adhesion at the interfacial border. We were able to obtain stable structures of the composite with the amount of fibers above 10% by volume. The presence of fibers in the silica matrix resulted in lower synthesis time of the composite, improved adhesion of fibers to the aerogel nanostructure, and increased mechanical and structural parameters. An additional effect of the presence of fibers in excess of 10% by volume was a new function of the nanocomposite—the ability to conduct electric current. The most optimal parameters of the composite, however, were obtained for silica aerogel reinforced with 10 vol.% of carbon fibers. This material indicated relatively low density and good physical parameters. The paper also analyzes the results on the synthesis of fiber-reinforced silica aerogels that have appeared in recent years and compares these to the results gained in presented work.

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Experimental Study on Cost-Effective Additive Manufacturing of Silica Aerogel

Volume 1: Additive Manufacturing; Advanced Materials Manufacturing; Biomanufacturing; Life Cycle Engineering; Manufacturing Equipment and Automation ◽

10.1115/msec2020-8510 ◽

2020 ◽

Author(s):

Zipeng Guo ◽

Ruizhe Yang ◽

Tianjiao Wang ◽

Lu An ◽

Shenqiang Ren ◽

...

Keyword(s):

Thermal Insulation ◽

Silica Aerogel ◽

Low Cost ◽

Ambient Pressure ◽

Cost Effective ◽

Supercritical Drying ◽

Ambient Pressure Drying ◽

Insulation Material ◽

Market Demand ◽

Insulation Property

Abstract The conventional manufacturing process of aerogel insulation material relies largely 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. The foam ink preparation methods and the printability are demonstrated in this paper, along with the printed samples for characterizing thermal insulation performance and mechanical properties.

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Silica Aerogel Monoliths Derived from Silica Hydrosol with Various Surfactants

Molecules ◽

10.3390/molecules23123192 ◽

2018 ◽

Vol 23 (12) ◽

pp. 3192 ◽

Cited By ~ 3

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.

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EFFECT of IONIC LIQUID CONTENT on MONOLITHIC STRUCTURE of AMINE-MEDIATED SILICA AEROGEL via AMBIENT PRESSURE DRYING

Journal of the Turkish Chemical Society Section A Chemistry ◽

10.18596/jotcsa.390372 ◽

2018 ◽

pp. 663-678

Author(s):

Nilay Gizli ◽

Selay SERT ÇOK ◽

Fatoş KOÇ

Keyword(s):

Ionic Liquid ◽

Silica Aerogel ◽

Ambient Pressure ◽

Ambient Pressure Drying ◽

Liquid Content ◽

Monolithic Structure

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

Science of Advanced Materials ◽

10.1166/sam.2021.4060 ◽

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.

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