There have been a number of review papers on layered silicate and carbon nanotube reinforced polymer nanocomposites, in which the fillers have high aspect ratios. Particulate–polymer nanocomposites containing fillers with small aspect ratios are also an important class of polymer composites. However, they have been apparently overlooked. Thus, in this paper, detailed discussions on the effects of particle size, particle/matrix interface adhesion and particle loading on the stiffness, strength and toughness of such particulate–polymer composites are reviewed. To develop high performance particulate composites, it is necessary to have some basic understanding of the stiffening, strengthening and toughening mechanisms of these composites. A critical evaluation of published experimental results in comparison with theoretical models is given.

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Effects of particle size, particle/matrix interface adhesion and particle loading on mechanical properties of particulate–polymer composites

Thermal conductivity of carbon nanotubes and their polymer nanocomposites: A review

Thermal Conductivity of Polymer-Based Composites: Fundamentals and Applications

A review of nanofluid stability properties and characterization in stationary conditions

Review of thermal conductivity in composites: Mechanisms, parameters and theory

In this study, the thermal conductivity and viscosity of TiO2 nanoparticles in deionized water were investigated up to a volume fraction of 3% of particles. The nanofluid was prepared by dispersing TiO2 nanoparticles in deionized water by using ultrasonic equipment. The mean diameter of TiO2 nanoparticles was 21 nm. While the thermal conductivity of nanofluids has been measured in general using conventional techniques such as the transient hot-wire method, this work presents the application of the 3ω method for measuring the thermal conductivity. The 3ω method was validated by measuring the thermal conductivity of pure fluids (water, methanol, ethanol, and ethylene glycol), yielding accurate values within 2%. Following this validation, the effective thermal conductivity of TiO2 nanoparticles in deionized water was measured at temperatures of 13 °C, 23 °C, 40 °C, and 55 °C. The experimental results showed that the thermal conductivity increases with an increase of particle volume fraction, and the enhancement was observed to be 7.4% over the base fluid for a nanofluid with 3% volume fraction of TiO2 nanoparticles at 13 °C. The increase in viscosity with the increase of particle volume fraction was much more than predicted by the Einstein model. From this research, it seems that the increase in the nanofluid viscosity is larger than the enhancement in the thermal conductivity.

Thermal Conductivity and Viscosity Measurements of Water-Based TiO2 Nanofluids

Thermal conductivity and mechanical properties such as tensile strength, elongation at break, and modulus of elasticity of aluminum powder-filled high-density polyethylene composites are investigated experimentally in the range of filler content 0–33% by volume for thermal conductivity and 0–50% by volume for mechanical properties. Experimental results from thermal conductivity measurements show a region of low particle content, 0–12% by volume, where the particles are distributed homogeneously in the polymer matrix and are not interacting with each other; in this region most of the thermal conductivity models for two-phase systems are applicable. At higher particle content, the filler tends to form ag-glomerates and conductive chains resulting in a rapid increase in thermal conductivity. The model developed by Agari and Uno estimates the thermal conductivity in this region. Tensile strength and elongation at break decreased with increasing aluminum particles content, which is attributed to the introduction of discontinuities in the structure. Modulus of elasticity increased up to around 12% volume content of aluminum particles. Einstein's equation, which assumes perfect adhesion between the filler particles and the matrix, explains the experimental results in this region quite well. For particle content higher than 30%, a decrease in the modulus of elasticity is observed which may be attributed to the formation of cavities around filler particles during stretching in tensile tests. © 1996 John Wiley & Sons, Inc.

Thermal and mechanical properties of aluminum powder-filled high-density polyethylene composites

Thermal conductivity of particle filled polyethylene composite materials

Thermal conductivity of copper powder filled polyamide composites are investigated experimentally in the range of filler content 0-30% by volume for particle shape of short fibers and 0-60% by volume for particle shapes of plates and spheres. The thermal conductivity of polymer composites is measured by the Hot-Disk method. It is seen that the experimental values for all the copper particle shapes are close to each other at low particle content, φ<10, as the particles are dispersed in the polyamide matrix and they are not interacting with each other. For particle content greater than 10% by volume, a rapid increase occurs in the thermal conductivity for the copper fibers filled polymer composite. As a result of this study, thermal conductivity of copper filled polyamide composites depends on the thermal conductivity of the filler particles, filler particle shape and size, and the volume fraction and spatial arrangement of the filler particles in the polymer matrix.

Ismail H. Tavman

Papers

Thermal Conductivity and Viscosity Measurements of Water-Based TiO2 Nanofluids

Thermal and mechanical properties of aluminum powder-filled high-density polyethylene composites

Thermal conductivity of particle filled polyethylene composite materials

Effect of Particle Shape on Thermal Conductivity of Copper Reinforced Polymer Composites

Effective thermal conductivity of granular porous materials