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Effect of Acidity Levels and Feed Rate on the Porosity of Aerogel from Rice Husk under Ambient Pressure

Title
Effect of Acidity Levels and Feed Rate on the Porosity of Aerogel from Rice Husk under Ambient Pressure
Author
김희택
Keywords
silica aerogel; rice husk; ambient pressure synthesis; rice husk aerogel
Issue Date
2019-02
Publisher
MDPI
Citation
NANOMATERIALS, v. 9, No. 2, Article no. 300
Abstract
Silica aerogels have attracted tremendous interest due to their high specific surface area and the physical, chemical, and mechanical properties as promising materials for thermal insulation, chemical sensors, and energy storage devices. However, large-scale production of silica aerogels remains a challenge due to costly alkoxide precursors and energy-intensive supercritical drying processes. This paper analyzes the effect of acidity levels and feed rate on the porosity of rice husk aerogels with high specific surface area under ambient pressure. This synthetic approach is cost-effective, eco-friendly, and facilitates recycling. Rice husk ash, which consists of 92% amorphous pure silica, was produced by combustion. A process of solvent exchange and surface modification under ambient pressure at different pH levels was conducted for synthesis of the aerogel. The specific surface area of rice husk aerogel was confirmed as ranging from 385 to 861 m(2)/g under pH 1 to pH 9 and acid feed rate of 0.5 to 5.0 mL/min. The optimized aerogel had a specific surface area of 861 m(2)/g, a pore volume of 3.33 cm(3)/g, and an average pore diameter of 12 nm when synthesized at pH 1 and an acid feed rate of 2.5 mL/min. The aerogel was found to be highly hydrophobic, with a water contact angle of 156 degrees up to about 340 degrees C.
URI
https://www.mdpi.com/2079-4991/9/2/300https://repository.hanyang.ac.kr/handle/20.500.11754/112327
ISSN
2079-4991
DOI
10.3390/nano9020300
Appears in Collections:
COLLEGE OF ENGINEERING SCIENCES[E](공학대학) > MATERIALS SCIENCE AND CHEMICAL ENGINEERING(재료화학공학과) > Articles
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2019.02_김희택_Effect of Acidity Levels and Feed Rate on the Porosity of Aerogel Extracted from Rice Husk under Ambient Pressure.pdfDownload
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