نتایج جستجو برای: silica aerogel

تعداد نتایج: 38570  

2005
C. E. Ashton N. Mulders A. I. Golov

A torsional oscillator has been used to study the flow of liquid 4He through silica aerogel. The tortuosity and dissipation of the flow in the fractal aerogel environment has been measured, for both capillary condensed films and a fully saturated cell. The scaling of tortuosity as a function of filling fraction has been investigated. We compare the results of our 88%-porous aerogel to a 92%-por...

2010
M. Alnaief I. Smirnova

Due to high surface area, low density, open pore structure and excellent insulation properties aerogels were intensively investigated in the past decades for diverse range of applications. The state of the art of aerogel production by supercritical drying is to produce monolithic aerogel, where the sol is aged in molds and dried by extraction with supercritical CO2. Aerogels in form of spherica...

Journal: :Chemical Engineering Journal 2022

Polymer aerogels are a promising, non-brittle alternative to silica aerogel, but limited by their very poor high-temperature stability. Polyimide is widely known for its high heat-resistance, however, degree of volume shrinkage common polyimide after exposure temperatures above 200 °C. Here, we present the aerogel-in-aerogel composites that comprise aerogel grains with nanoparticulate microstru...

In the present study, silica aerogel- egg shell was synthesized for dye removal of colored wastewater. The nano composite structure was characterized by Fourier transform infrared spectra FTIR and scanning electron microscope SEM.The ability of nano composite absorption was assessed for removal basic violet 16BV16 dye from aqueous solutions and was compared with two other adsorbents such as egg...

Journal: :Materials & Design 2022

• Comprehensive review of all approaches used to assemble aerogel-fiber materials. “In situ sol-gel” and “via pre-formed aerogel” are described evaluated. Enhanced mechanical/physical properties obtained while keeping low thermal conductivity. An overview the market future research trends identified. Silica aerogels have a unique structure that makes them promising materials for variable applic...

2016
Sofia Ximenes Ana Silva António Soares Inês Flores-Colen Jorge de Brito

Statistical models using multiple linear regression are some of the most widely used methods to study the influence of independent variables in a given phenomenon. This study's objective is to understand the influence of the various components of aerogel-based renders on their thermal and mechanical performance, namely cement (three types), fly ash, aerial lime, silica sand, expanded clay, type...

2016
NIKOLAOS A. VAINOS VAGELIS KAROUTSOS BEN MILLS ROBERT W. EASON MICHEL PRASSAS

A novel route is presented enabling minimization of feature sizes via laser ablative micro-patterning in highly porous silica aerogel monoliths and subsequent viscous sintering. Vitrification yields isotropically contracted silica solids preserving their original stereometric forms. The contraction depends on aerogel structure and porosity and we demonstrate here the first realization of a 3:1 ...

2012
Hexin Zhang Changqing Hong Yingjie Qiao

Nano-porous silica aerogels are unique materials often having a high specific surface area, a high porosity (75-99%), a low thermal conductivity (0.01-0.03W/mK), and a low index of refraction. Because of their unique properties, aerogels have been extensively studied, not only for use as transparent thermal insulators but also as inter-metal dielectric materials, optical and acoustic applicatio...

2008
J. Pollanen

Measurements of superfluid He in 98% aerogel demonstrate the existence of a metastable A-like phase and a stable B-like phase. It has been suggested that the relative stability of these two phases is controlled by anisotropic quasiparticle scattering in the aerogel. Anisotropic scattering produced by axial compression of the aerogel has been predicted to stabilize the axial state of superfluid ...

Journal: :Optics Express 2010

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید