High thermal capacity silica-based fibers for potential application as insulators

C. Robinson, A. Sahu, S. Banks, R. Nelson
American Nano, LLC,
United States

Keywords: silica, thermal stability, polymer


Herein we report a novel isomeric, hydrated, silica-based polymer in fiber form with excellent insulative properties. Thermal conductivity, under steady state conditions, ranges between 0.017 W/mK (at ~250°C) to 0.099 W/mK (at ~1200°C). To our knowledge, this is amongst the lowest reported values for application-based materials currently available. The fibers have a high aspect ratio with tunable cross-linked morphological features. Both chemical composition and physical characteristics of the material contribute to its high thermal capacity. Flammability tests (at ~ 2000 °C) and thermogravimetric analysis (TGA) confirmed exceptional thermal stability, minimal to nonexistent degassing, and no mass loss. Characteristic morphological properties and chemical composition of the material were validated via extensive elemental and imaging analyses including scanning electron microscopy/energy-dispersive x-ray spectroscopy (SEM/EDX), powder x-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), as well as proton, carbon, and silicon nuclear magnetic resonance (NMR). Large scale production, and a certain degree of tunability in the aspect ratio of the fibers, have been established following a proprietary manufacturing process. The material has promising applicability as an insulator for high temperature and cryogenic conditions. Additionally, its nondegradable and nontoxic properties can be exploited for numerous environmental and medical applications.