The effect of nanoparticle agglomeration on the elastic and thermal properties of composites with an interphase
Jing Pan, Jinghong Liu, Xiaojian Liu, Lingbo Zhang, Wei Wang
Abstract
The interface plays a crucial role in nanoparticle-reinforced composite materials. So this article presents a micromechanical model to predict the elastic and thermal properties of composites comprising nanoparticles encapsulated by an interphase. Nanoparticles are easy to agglomerate in the matrix because of their large surface area ratio. Therefore, the study focuses on the effect of nanoparticles agglomeration on the elastic modulus and thermal expansion coefficient (CTE). In the present study, the regions with concentrated particles are assumed to be spherical in shape and are considered as inclusions. The size efficiency factor is introduced to reflect the influence of the agglomerated inclusions diameter in the analysis. The effects of the volume fractions, radius, and agglomerated degree of nanoparticles, and also the thickness and properties of the interphase are studied in detail. The micromechanical method is used to predict the effective elastic and thermal properties of nanoparticles reinforced three-phase composites. Analysis shows that the agglomeration of nanoparticles has a significant effect on the elastic modulus and thermal expansion coefficient of composites. The agglomeration of nanoparticles reduces the elastic modulus of the composites, but increases the thermal expansion coefficient of the composites. Increasing the thickness of the interface enhances the elastic modulus of composites, while increasing the particle radius reduces the elastic modulus of composites. Besides, the more severe the agglomeration of particles, the larger the coefficient of thermal expansion of the composites. The present study will provide a theoretical basis for the preparation and practical application of particle reinforced composites.