کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1484348 1510523 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Globally anisotropic high porosity silica aerogels
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Globally anisotropic high porosity silica aerogels
چکیده انگلیسی

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.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Non-Crystalline Solids - Volume 354, Issues 40–41, 15 October 2008, Pages 4668–4674
نویسندگان
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