Journal of Sol-Gel Science and Technology

, Volume 41, Issue 2, pp 139–146

Effective preparation of crack-free silica aerogels via ambient drying

  • Sung-Woo Hwang
  • Hae-Hyun Jung
  • Sang-Hoon Hyun
  • Young-Soo Ahn
Article

DOI: 10.1007/s10971-006-0513-y

Cite this article as:
Hwang, SW., Jung, HH., Hyun, SH. et al. J Sol-Gel Sci Technol (2007) 41: 139. doi:10.1007/s10971-006-0513-y

Abstract

Effective ambient-drying techniques for synthesizing crack-free silica aerogel bulks from the industrial waterglass have been developed. Silica wet gels were obtained from aqueous colloidal silica sols prepared by ion-exchange of waterglass solution (4–10 wt% SiO2). Crack-free monolithic silica aerogel disks (diameter of 22 mm and thickness of 7 mm) were produced via solvent exchange/surface modification of the wet gels using isopropanol/trimethylchlorosilane/n-Hexane solution, followed by ambient drying. The effects of the silica content in sol and the molar ratio of trimethylchlorosilane/pore water on the morphology and property of final aerogel products were also investigated. The porosity, density, and specific surface area of silica aerogels were in the range of 92–94%, 0.13–0.16 g/cm3, and ∼675 m2/g, respectively. The degree of springback during the ambient drying processing of modified silica gels was 94%.

Keywords

AerogelSilicaSurface modificationAmbient drying

Copyright information

© Springer Science + Business Media, LLC 2006

Authors and Affiliations

  • Sung-Woo Hwang
    • 1
  • Hae-Hyun Jung
    • 1
  • Sang-Hoon Hyun
    • 1
  • Young-Soo Ahn
    • 2
  1. 1.School of Advanced Materials Science and EngineeringYonsei UniversitySeoulKorea
  2. 2.korea Institute of Energy ResearchDaejeonKorea