Silica aerogels are frequently employed as solid desiccants in enthalpy wheels for dehumidifying the supply stream in air-conditioning systems. These desiccant materials possess good moisture adsorption and desorption characteristics due to their porous structure. Analysis of adsorption and desorption isotherms is critical for performance characterization and is often performed to evaluate the ...

Tetraethoxy orthosilicate (TEOS) was used not only as a precursor of silica, but also as an agent which reinforces the skeleton of silica-gel to prepare an aerogel and resultant silica and silica-alumina with large pore size and pore volume. In this gel skeletal reinforcement, the strength of silica aerogel skeleton was enhanced by aging with TEOS/2-propanol mixed solution to prevent the shrink...

the silica aerogel was prepared by the acid–base sol–gel polymerization of tetraethylorthosilicate precursor followed by ambient pressure drying. the prepared silica aerogels were characterized by fourier transform infrared )ft-ir(, thermo-gravimetric and differential thermal analysis )tg/dta(, x-ray diffractometer )xrd(, energy dispersive x-ray microanalysis )edx(, brunauer–emmitt–teller (bet)...

Buildings consume too much energy. For example, 16.6% of all the energy used in the United States goes towards just the heating and cooling of buildings. Many governments, organizations, and companies are setting very ambitious goals to reduce their energy use over the next few years. Because the time periods for these goals are much less than the average lifetime of a building, existing buildi...

Hierarchically structured carbon-silica aerogel (CSA) composites were synthesized from cheap water glass precursors and granulated activated carbon via a post-synthesis surface modification with trimethylchlorosilane (TMCS) and a low-cost ambient pressure drying procedure. The resultant CSA composites possess micro/mesoporous structure and hydrophobic surface. The adsorption and desorption perf...

The Stardust Mission used silica aerogel as the hypervelocity particle capture and return material since silica aerogel was the most reproducible to manufacture and the most thoroughly evaluated type of aerogel at the time [1]. However, the Stardust Science Team recognized that the use of silica aerogel, while expedient, introduced limits to mission’s eventual science return. This is due to the...

We have examined the superfluidity of 3He in 98.2% porous silica aerogel with up to 34% 4He at 21.6 bars. The mixture is phase separated for 4He fractions between ,11% and 34%, and the 4Herich phase preferentially occupies the regions of highest silica density in the aerogel, thus modifying the distribution of the correlated disorder seen by superfluid 3He. The 3He Tc increases slightly with 4H...

Silica monolith aerogels with different degrees of hydrophobicity by incorporating methyltrimethoxysilane (MTMS) or trimethylethoxysilane (TMES) in standard sol-gel synthesis were prepared. Excellent properties of aerogels, obtained with the sol-gel synthesis, were preserved with supercritical drying with CO2. The degree of hydrophobicity of the aerogels was tested by measuring the contact angl...

Introduction: Great care and a large effort was made to minimize the amount of organic matter contained within the flight aerogel used to collect Comet 81P/Wild 2 samples [1]. Even so, by the very nature of the production process and silica aerogel’s affinity for volatile organics keeping silica aerogel free from organics is a monumental task. Silica aerogel from three production batches was fl...

The silica aerogel was prepared by the acid–base sol–gel polymerization of tetraethylorthosilicate precursor followed by ambient pressure drying. The prepared silica aerogels were characterized by Fourier transform infrared )FT-IR(, Thermo-gravimetric and differential thermal analysis )TG/DTA(, X-ray diffractometer )XRD(, Energy dispersive X-ray microanalysis )EDX(, Brunauer–Emmitt–Teller (BET)...