3D reconstruction of porous materials through FIB-SEM

Concept of 3D acquisition in FIB-SEM

The one particular technique available on the FIB-SEM is referred to as Serial Sectioning Tomography, which is the creation of 3D datasets with nanoscale resolution within a representative volume from the specimen, this can be applied to a large variety of materials. [2]

Example 1

Diatomite also referred to as diatomaceous earth, is a fragile rock that consists of loosely bound fossilized unicellular diatom algae. As a consequence, this material has high porosity and thus high permeability, high surface area, and low density.

These properties make this material particularly interesting as a heavy metal adsorbant for contaminant removal and for catalysis e.g., for the generation of phenol, as a catalytic substrate. 

All these processes are dependent on the interconnectivity of the porosity and accessibility of the surface area, thus 3D visualization can provide a wealth of information about how gases and liquids can permeate these materials.

Example 2

Olivine is a useful input material for a lot of different industrial processes including the neutralization of highly acidic fluids and industrial carbon dioxide sequestration. Amorphous silica can be produced through the experimental reaction of olivine with an acidic solution. 

The formation and properties of newly precipitated material on olivine surfaces will control further reactivity as it will mediate the ability of reactive fluid species to access the reacting interface. The reaction of olivine produced an amorphous silica pseudomorph around the original olivine grain that appeared to be layered from 2D imaging and 3D reconstruction. The layering in reacted silica shows a discrete separation with high porosity. [3]