Epoxy‐silica nanocomposites: Preparation, experimental characterization, and modeling

Abstract

ABSTRACT:Silica nanoparticles having different sizes were obtained by the sol-gel process and characterized. The prepared nanoparticles were subsequently used as reinforcing fillers to prepare epoxy-based composites with a silica content ranging from 1 to 5 wt %. SEM analysis and tensile tests carried out on the silica-epoxy nanocomposites indicated the absence of particle aggregation and a reinforcing effect in terms of increased elastic modulus. Mechanical properties were also modeled by using a finite element code able to construct a numerical model from a microstructural image of the material. A more reliable model was prepared by considering the presence of an interphase layer surrounding the particles with intermediate elastic properties between the epoxy and the inclusions and a characteristic size proportional to the particle radius.

Synergistic Effects of Mixed Silica Micro-nanoparticles on Compressive Dynamic Stiffness and Damping of Epoxy Adhesive

“…Pure nanoparticles at 2 wt% silica are well dispersed, achieving a large effective interface area; therefore, these provide stronger stiffening effects than those of micro-nanoparticles. Good dispersion of low-content silica nanoparticles was observed, which is in agreement with previous works by Bondioli et al [10], Zheng et al [9], and Feli and Jalilian [8]. This result suggests that composing silica micro and nanoparticles in appropriate ratios improves their dispersion up to certain weight fraction when using only a conventional mechanical mixer.…”

“…Welldispersed silica nanoparticles stiffen and toughen an epoxy adhesive more efficiently than silica microparticles owing to their larger surface-to-volume ratio, forming a more substantial matrix-filler interface area at a given weight fraction [1][2][3][4][5][6][7]. However, without any treatment, high-silica-content nanoparticles are difficult to disperse uniformly using a conventional mechanical mixer and tend to aggregate/agglomerate in the epoxy matrix [8][9][10].…”

Epoxy/Silica Nanocomposites: Nanoparticle‐Induced Cure Kinetics and Microstructure

“…Fundamental understanding is very limited in the field and often leads to the conclusion that approaches commonly used for particulate composites are not suitable when a nanometric phase is involved. [4] There have been significant efforts over the past decade to develop modified epoxies with various nano-additives including carbon nanotubes/fibres, exfoliated nanoclays, and organic/inorganic nanoparticles. However, few systems have achieved uniform dispersions of nanoparticles without agglomeration.…”

Characterizing and Modeling Mechanical Properties of Nanocomposites-Review and Evaluation

“…2. It is observed that for some nanocomposites, with the same filler volume fraction, the stiffness and strength increases as the particle size decreases [125,182,[224][225][226][227].…”