Filtration of Nanometric Airborne Particles Using A new Generation of Aerogel Filters

Abstract

Aerogels are special class of nano-porous materials with porosity about 98% and pore size typically in the range 10-30 nm. These materials can be use in filtration but they have to be strengthened with support materials, such as e.g. glass fibre mats (HEPA membrane). This work presents the results of study on aerodynamic properties and applicability tests of silica aerogel filters produced by impregnation of glass fibre mat (HEPA membrane) with silica sol and drying it in supercritical conditions. The new filter mats were tested aerodynamically and it was found that their resistance to airflow is only two times higher than the original glass fibre substrate. Particle retention tests have been carried out successfully. The results indicate that silica aerogel impregnated glass fibre mats can provide a good substrate for production of ultra HEPA filters retaining nanometric airborne particles.