Super-Compressibility of Ultralow-Density Nanoporous Silica



original image

Porosity generally embrittles ceramics. In contrast to such expectations, this report demonstrates that an effective fracture strain of nanoporous silica aerogels increases with increasing porosity. At ultralow relative densities of <0.5%, nanoporous monoliths start exhibiting super-compressible deformation with effective fracture strains of >50%. This is attributed to consequences of an increase in the aspect ratio of ligaments with decreasing density.