Simulation and Analysis of Mechanical Properties of Silica Aerogels: From Rationalization to Prediction

Abstract

Silica aerogels are highly porous 3D nanostructures and have exhibited excellent physio-chemical properties. Although silica aerogels have broad potential in many fields, the poor mechanical properties greatly limit further applications. In this study, we have applied the finite volume method (FVM) method to calculate the mechanical properties of silica aerogels with different geometric properties such as particle size, pore size, ligament diameter, etc. The FVM simulation results show that a power law correlation existing between relative density and mechanical properties (elastic modulus and yield stress) of silica aerogels, which are consistent with experimental and literature studies. In addition, depending on the relative densities, different strategies are proposed in order to synthesize silica aerogels with better mechanical performance by adjusting the distribution of pore size and ligament diameter of aerogels. Finally, the results suggest that it is possible to synthesize silica aerogels with ultra-low density as well as high strength and stiffness as long as the textural features are well controlled. It is believed that the FVM simulation methodology could be a valuable tool to study mechanical performance of silica aerogel based materials in the future.

Modelling of Mechanical Behavior of Biopolymer Alginate Aerogels Using the Bonded-Particle Model

“…Two different regimes are identifiable: an elastic and a plastic range. The results are in good agreement with general theory of mechanical behavior of foamed structures and reported results for aerogels [29,30]. However, due to the high material porosity, no densification regions were observed for samples with CaCl2 concentrations of 0.5 and 1 g/L.…”

“…Kim and Buttlar [27] have proposed bilinear cohesive model, Tran V.T., Donze F.V., Marin P. [28] have applied a elastic-hardening-damage law to reproduce irreversible compaction for concretes under high confining pressure. For the simulation of failure behavior of quasi-brittle materials Ma et al [29] proposed a displacement-softening contact model.…”

Mechanical response of mesoporous amorphous NiTi alloy to external deformations

“…6(a) shows the set of the stress-strain curves obtained for the samples with various porosity. Each curve has a step, that is typical for materials with a porous structure, for example, metal foams and aerogels [59,60]. This step arises due to collapse of the pores.…”

Effect of the porosity and microstructure on the mechanical properties of organic xerogels

“…When using monoliths, their mechanical properties become a fundamental issue [3,5]. The dependence of the mechanical properties of monoliths on their microstructure has been studied extensively for materials such as foams, carbons and silica aerogels, suggesting that there is a universal correlation based on the chemical structure of each type of material [3,4,6,[8][9][10][11][12]. This dependence is usually represented by a mathematical correlation (power law) between mechanical parameters such as modulus and strength, and the densities of the studied materials [9,[13][14][15][16][17].…”