Development of thermal liner for extreme heat protective clothing using aerogel technology

Abstract

In this research, an attempt was made to develop and explore the thermal protective performance of the thermal liner and the effect of various preparation parameters of aerogel technology on it. Efforts have also been made to explore the scope of nanotechnology in finding the solution to problems coming in the way of high thermal stability and insulation of the thermal liner. Silica aerogel is a colloidal suspension of silica-based oxides in the air. Hence, it is a highly insulating material and shows one of the lowest densities for a similar performance. Here we took an approach to deploy silica aerogel composite as a thermal liner layer in order to ensure the aforesaid functionalities. To realize the objective, we tried to find the suitable fibre as well as suitable fabric structure for developing an aerogel on it. Further, we studied the effect of processing parameters such as ageing time, the effect of base catalyst and silylation time during aerogel synthesis on the protective performance of the developed thermal liner. Electrospun Nomex® fibre-aerogel composite and nomex® fibre-aerogel composite was also made, and it was compared to the thermal liner made of Nomex® IIIA nonwoven to find out how it worked. Aerogel treated sample with ammonium fluoride as catalyst performed best compared to sample with ammonium hydroxide as a base catalyst. An increase in ageing and silylation time led to significant increase in the thermal protective performance of the developed aerogel-Nomex® composite due to a better aerogel formation inside the composite.