Engineering and physical science
Faster Production of Aerogel Monoliths
Aerogels are used for a wide variety of applications, yet they are still limited by certain aspects of their production. One of the most prohibitive steps of manufacture is solvent exchange. This step is usually necessary because the solvents used in the wet gel formation cannot be present when the aerogel is being supercritically dried to preserve its porosity. Solvent exchange adds expense due to the amount of fresh solvent needed for complete exchange. In order to ensure complete diffusion, the solvent exchange process is very time consuming and limits the size of aerogel that can be produced.
Dr. Massimo Bertino has developed a new method that allows for larger monoliths to be formed in a shorter amount of time. This process uses supercritical ethanol during the drying process, and due to a modification in the wet gel chemistry, does not require solvent exchange. Without the need transfer to fresh solvent batches, the process becomes more cost efficient and synthesis can be performed in a single step. With this method, the size of the monolith is no longer limited by the time required for complete solvent exchange. If required, Cross-linking with a polymer can be carried out to increase the mechanical strength of the monoliths without any increase in processing cost or time. The increased strength expands the applications to include ballistic protection, shock absorption, and thermal protection. Functionally graded, honeycomb sandwiched and cellular solid structures can also be produced.