Modifying the Pore Size of Resorcinol Formaldehyde Aerogels for Fabrication of Hollow Spheres for Direct Drive ICF Experiments

Abstract

AbstractThis work investigates an alternative way to modify the pore size of a 100 mg/cc resorcinol formaldehyde (R/F) aerogel without any significant change to the aerogel target density. This was successfully accomplished by an addition of hydrophilic polymer additive [Poly Vinyl Alcohol (PVA) or Poly Acrylic Acid (PAA)] to the R/F precursor solution which acts as an impurity in the reaction. The polymer can modify the cross linking or aggregation of the primary particles which can change the structure formation of the aerogel, thus changing the pore size. This paper will discuss this process modification and the fabrication of hollow, large pore R/F aerogel spheres that are used for direct drive inertial confinement fusion (ICF) cryogenic ice layering experiments at the University of Rochester Laboratory for Laser Energetics (LLE). The aerogels were characterized using scanning electron microscopy (SEM), nitrogen gas adsorption, and ultra small angle x-ray scattering (USAXS).