A quantitative method for analysing the dispersion of carbon nanotubes in cement composite materials

The dispersion of carbon nanotubes (CNTs) within cement-based composite materials plays a key role in determining many essential properties. In this study, a method to quantify the dispersion of CNTs within cement-based composite materials has been developed. The dispersion quantity, D, is measured by the particle size rather than the free-path spacing between particles. The particle sizes are given in terms of the true length/nm rather than pixels. A Gaussian function is used as the probability density function (PDF) fits a Gaussian distribution better than a lognormal distribution depending on the statistical data and the true diameter of CNTs. Higher D values indicate a better dispersion of CNTs in the matrix. The method works well to quantify the dispersion of particles, especially for filaments such as CNTs, and is simple and useful.