Journal of Materials Science

, Volume 42, Issue 9, pp 3207–3214

Low density TEOS based silica aerogels using methanol solvent

  • Sharad D. Bhagat
  • Hiroshi Hirashima
  • A. Venkateswara Rao
Article

DOI: 10.1007/s10853-006-1366-z

Cite this article as:
Bhagat, S.D., Hirashima, H. & Venkateswara Rao, A. J Mater Sci (2007) 42: 3207. doi:10.1007/s10853-006-1366-z

Abstract

Highly transparent monolithic silica aerogels based on the TEOS precursor were prepared by the two-step (acid-base) sol–gel process. The hydrolysis and condensation reactions of tetraethoxysilane (TEOS) proceeded in methanol solvent with oxalic acid and NH4OH as the catalysts, respectively. The wet gels were supercritically dried using methanol. The aerogels were characterized by transmission electron microscopy (TEM) and measurements of optical transmission, bulk density, volume shrinkage, porosity and thermal conductivity. Monolithic silica aerogels with high optical transmission (∼93%), low density (∼0.055 g/cm3), low thermal conductivity (∼0.04 W/mK), and minimum volume shrinkage (∼10%), were obtained for the molar ratio of TEOS:MeOH:acidic H2O:basic H2O at 1:33:3.5:3.5 alongwith the oxalic acid and NH4OH concentrations at 0.001 M and 1 M, respectively.

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Sharad D. Bhagat
    • 1
  • Hiroshi Hirashima
    • 2
  • A. Venkateswara Rao
    • 1
  1. 1.Air Glass Laboratory, Department of PhysicsShivaji UniversityKolhapurIndia
  2. 2.Faculty of Science and TechnologyKeio UniversityKohoku-kuJapan