Facile Preparation of Nanoporous Silica Aerogel Granules

나노다공성 실리카 에어로겔 과립의 간단 제조

  • Kim, Nam Hyun (Korea Packaging Center, Korea Institute of Industrial Technology) ;
  • Hwang, Ha Soo (Korea Packaging Center, Korea Institute of Industrial Technology) ;
  • Park, In (Korea Packaging Center, Korea Institute of Industrial Technology)
  • 김남현 (한국생산기술연구원 패키징기술센터) ;
  • 황하수 (한국생산기술연구원 패키징기술센터) ;
  • 박인 (한국생산기술연구원 패키징기술센터)
  • Received : 2011.01.10
  • Accepted : 2011.02.24
  • Published : 2011.04.10

Abstract

Hydrophobic silica aerogel beads with low thermal conductivity and high porosity were prepared using a cost-effective sodium silicate as a silica source via an ambient-pressure drying process. Monolithic wet gels were first prepared by adjusting pH (~5) of a diluted sodium silicate solution. The silica aerogel beads (0.5~20 mm) were manufactured by breaking the wet gel monoliths under a simultaneous solvent exchange/surface modification process and an ambient-pressure drying process without using co-precursors or templates. Dried silica aerogel beads exhibit a comparable porosity ($593m^2/g$ of surface area, 34.9 nm of pore size, and $4.4cm^3/g$ of pore volume) to that of the aerogel powder prepared in the same conditions. Thermal conductivity of the silica aerogel beads (19.8 mW/mK at $20^{\circ}C$) is also identical to the aerogel powder.

Keywords

aerogel;granule;ambient pressure drying;thermal insulator

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