Prediction of Thermal Conductivity of Composites with Spherical Microballoons

Abstract

A new model for predicting the thermal conductivities of a composite with spherical microballoons is proposed and consists of two consecutive procedures, the computation of the thermal conductivity of the microballoon and the composite. The microballoon is first replaced by the equivalent filler of a known thermal conductivity, so the composite is treated as the matrix containing the equivalent fillers and its thermal conductivity is derived by using Eshelby model modified with Mori-Tanaka's mean field approach. The present model is validated comparing the predicted, experimental, and numerical results from the literature. Parametric studies in terms of the microballoon volume fraction, its relative wall thickness, and the thermal conductivity ratio of the shell to the matrix have been made and their results are discussed.

Thermal conductivity of cementitious composites containing microencapsulated phase change materials

“…Several effective medium approximations (EMAs) have been proposed to predict the effective thermal conductivity of three-component core-shell-matrix composites such as cement paste with embedded microencapsulated PCM [13,[39][40][41][42][43].…”

“…In addition, the effective thermal conductivity k c+s of the core-shell particles could be predicted by a model developed by Park et al [39] and expressed as passing through the 600 µm sieve and 0-4% passing through the 150 µm sieve [48].…”

Glassy Microspheres for Energy Applications

“…A cost-effective solution to reduce this energy waste consists in minimizing the solar heat load and the heat dispersion through the roof and walls by using insulator coating materials that have low thermal conductivity and high infrared radiation reflectivity [ 62 , 63 ]; multiple layer thermal insulation coatings may be the most effective solution [ 63 ]. The thermal characteristics of HGM have been the subject of several papers, where different aspects were investigated, such as the mechanism of heat transfer in HGM [ 64 , 65 ] or the effect of inclusion of HGM in different materials [ 66 , 67 , 68 , 69 , 70 , 71 , 72 ]. Figure 5 shows a typical scanning electron microscope (SEM) image of soda-lime silicate glass microbubbles fabricated by Sinosteel Maanshan New Material Technology (Maanshan, China) [ 64 ].…”

Thermal conductivity and compressive properties of hollow glass microsphere filled epoxy–matrix composites

“…This composite was further converted (Figure 1(b)) by using Eshelby's equivalent inclusion method. 23 The thermal conductivity of the composites can be evaluated according to effective thermal conductivity models. Many effective thermal conductivity models have been developed to predict the effective thermal conductivity of polymer-matrix composite.…”