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

doi:10.1016/j.jnoncrysol.2008.05.047

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

Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

37 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 language	English (US)
Pages (from-to)	4668-4674
Number of pages	7
Journal	Journal of Non-Crystalline Solids
Volume	354
Issue number	40-41
DOIs	https://doi.org/10.1016/j.jnoncrysol.2008.05.047
State	Published - Oct 15 2008

Funding

This work was supported by the National Science Foundation, DMR-0703656. Use of the Advanced Photon Source was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

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

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10.1016/j.jnoncrysol.2008.05.047

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title = "Globally anisotropic high porosity silica aerogels",

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.",

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

author = "J. Pollanen and Shirer, {K. R.} and S. Blinstein and Davis, {J. P.} and H. Choi and Lippman, {T. M.} and Halperin, {W. P.} and Lurio, {L. B.}",

note = "Funding Information: This work was supported by the National Science Foundation, DMR-0703656. Use of the Advanced Photon Source was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.",

year = "2008",

month = oct,

day = "15",

doi = "10.1016/j.jnoncrysol.2008.05.047",

language = "English (US)",

volume = "354",

pages = "4668--4674",

journal = "Journal of Non-Crystalline Solids",

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publisher = "Elsevier B.V.",

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TY - JOUR

T1 - Globally anisotropic high porosity silica aerogels

AU - Pollanen, J.

AU - Shirer, K. R.

AU - Blinstein, S.

AU - Davis, J. P.

AU - Choi, H.

AU - Lippman, T. M.

AU - Halperin, W. P.

AU - Lurio, L. B.

N1 - Funding Information: This work was supported by the National Science Foundation, DMR-0703656. Use of the Advanced Photon Source was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

PY - 2008/10/15

Y1 - 2008/10/15

N2 - 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.

AB - 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.

KW - Aerogels

KW - Mechanical, stress relaxation

KW - Optical properties

KW - Porosity

KW - Silica

KW - Sol-gel, aerogel and solution chemistry

KW - Superfluid He

KW - X-rays

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U2 - 10.1016/j.jnoncrysol.2008.05.047

DO - 10.1016/j.jnoncrysol.2008.05.047

M3 - Article

AN - SCOPUS:51349138673

SN - 0022-3093

VL - 354

SP - 4668

EP - 4674

JO - Journal of Non-Crystalline Solids

JF - Journal of Non-Crystalline Solids

IS - 40-41

ER -

Globally anisotropic high porosity silica aerogels

Abstract

Funding

Keywords

ASJC Scopus subject areas

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