Globally anisotropic high porosity silica aerogels

J. Pollanen, K. R. Shirer, S. Blinstein, J. P. Davis, H. Choi, T. M. Lippman, W. P. Halperin*, L. B. Lurio

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

28 Scopus citations

Abstract

We discuss two methods by which high porosity silica aerogels can be engineered to exhibit global anisotropy. First, anisotropy can be introduced with axial strain (i.e. axial compression). In addition, intrinsic anisotropy can result during growth and drying stages and, suitably controlled, it can be correlated with preferential radial shrinkage in cylindrical samples. We have performed small angle X-ray scattering (SAXS) to characterize these two types of anisotropy. We show that global anisotropy originating from either strain or shrinkage leads to optical birefringence and that optical cross-polarization studies are a useful characterization of the uniformity of the imposed global anisotropy.

Original languageEnglish (US)
Pages (from-to)4668-4674
Number of pages7
JournalJournal of Non-Crystalline Solids
Volume354
Issue number40-41
DOIs
StatePublished - Oct 15 2008

Keywords

  • Aerogels
  • Mechanical, stress relaxation
  • Optical properties
  • Porosity
  • Silica
  • Sol-gel, aerogel and solution chemistry
  • Superfluid He
  • X-rays

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Condensed Matter Physics
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Globally anisotropic high porosity silica aerogels'. Together they form a unique fingerprint.

Cite this