Computational Hierarchy Modeling of Self-assembled Polyurea Aerogels

G.D. Chen
Missouri University of Science and Technology, US

Keywords: nanomechanics, polyurea aerogels, molecular dynamics, computer simulations

Summary:

An economical environmentally friendlier synthesis of nanoporous polyurea aerogels from triisocuyanates and water has recently been described. Owing to their multi-functionality and superior mechanical properties, those materials are finding their way into various engineering applications. This paper describes a theoretical framework to computationally simulate the molecular dynamics of the aerogel within a united atom model at different scales. The united atom model was validated by comparing the simulated failure mechanisms and mechanical properties under tension and compression with the corresponding experimental data at various load rates. The self-assembly of elementary nanoparticles into the fractal hierarchical structure of polyurea aerogels was represented by a phenomenological model that was validated by comparing the simulated three-dimensional fiber-type nanostructure with that reconstructed from a series of two-dimensional surface images.