کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1482528 | 1510483 | 2011 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Effect of uni-axial loading on the nanostructure of silica aerogels Effect of uni-axial loading on the nanostructure of silica aerogels](/preview/png/1482528.png)
Aerogels are unique materials offering a combination of remarkable properties that make them useful in a wide range of applications. However, aerogel materials can be difficult to work with because they are fragile. The intent of the work presented here was to study the relationship between axial loading and pore structure in aerogel material. Silica aerogel samples with a bulk density of 0.1 g/mL were compressed by uni-axial force loads from 1 to 5 kN which resulted in stress levels up to 23 MPa. The resulting change in the pore distribution was observed using nitrogen desorption analysis and scanning electron microscopy. Uncompressed aerogel samples exhibit peak pore volume at diameters of about 20 nm. As the aerogels are subjected to increased loading, the location of the peak volume moves to smaller diameters with a reduced volume of pores occurring above this diameter. The peak diameter, the average pore diameter and pore volume all decrease and scale with increasing maximum stress while the surface area of the aerogel samples remains unaffected at about 520 m2/g. When combined with data from the literature, the relation between maximum pore diameter and applied stress suggests a failure mechanism dominated by bending induced fracture.
Research highlights
► Study on the relationship between axial loading and pore structure in silica aerogels.
► Pore size and pore volume scale with the maximum applied pressure.
► Evidence that the failure mechanism may be dominated by bending induced fracture.
Journal: Journal of Non-Crystalline Solids - Volume 357, Issues 16–17, August 2011, Pages 3176–3183