Facile Incorporation of Optical Sensitizers into Nitrocellulose Aerogels for Improved Laser Ignition and Combustion

Abstract

We demonstrate a straightforward and effective method to achieve uniform infiltration of optical sensitizers into nitrocellulose aerogels using a sol-gel method followed by supercritical carbon dioxide drying. The optical sensitizers employed in this study include gold nanoparticles (AuNPs) capped with self-assembled monolayers of hydroxyl and/or carboxylic functional groups (i.e., OH-AuNPs and COOH-AuNPs) as well as carboxylated multi-walled carbon nanotubes (c-MWCNTs). The resulting robust, monolithic aerogels were characterized in detail by using scanning electron microscopy (SEM), specific surface area measurements, differential scanning colorimetry (DSC), and laser initiation and combustion. Although the composite aerogels exhibited similar surface areas, morphologies, and microstructures as pure nitrocellulose aerogels, they exhibited increased sensitivity to laser stimuli and demonstrated improved combustion properties compared to pure nitrocellulose aerogels. We attribute these enhanced performances to the possible increase in photothermal conversion and thermal conductivity facilitated by the incorporation of optical sensitizers within the aerogels. This study offers valuable insights into the design and development of advanced nitrocellulose-based energetic materials, potentially leading to advancements in laser initiation and combustion technologies.