Globally Anisotropic High Porosity Silica Aerogels

Autor:	Pollanen, J., Shirer, K., Blinstein, S., Davis, J. P., Choi, H., Lippman, T. M., Lurio, L. B., Halperin, W. P.
Rok vydání:	2007
Předmět:	Condensed Matter - Other Condensed Matter
Druh dokumentu:	Working Paper
DOI:	10.1016/j.jnoncrysol.2008.05.047
Popis:	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. 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. Comment: 18 pages, 14 figures, submitted to Journal of Non-Crystalline Solids
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/0711.3495 Zobrazit plný text záznamu View this record from Arxiv