Dispersion of High Concentrations of Carbon Nanofibers in Portland Cement Mortars

Figure 4

Examples of the geometric clustering of nanoparticles due to the particle size dispersion of cement grains. (a) A cement grain particle size distribution based on the OPC with a cement grain area fraction of 0.6. (b) The particle size distribution from (a) with 2107 nanoparticle centroids randomly dispersed among the grains. (c) The nanoparticle centroids in (b) without the cement grains from (a) showing the unreinforced regions left from the cement grains. (d) A cement grain particle size distribution based on the microfine cement with a cement grain area fraction of 0.6; a sample size element is placed in (a) that shows the relative size of the images. (e) The particle size distribution from (d) with the same number of nanoparticle centroids in (b) randomly dispersed among the grains. (f) The nanoparticle centroids dispersed in (e) without the cement grains from (d) showing unreinforced regions left by the cement grains, but overall potential dispersion is improved with the use of microfine cement when compared to (c).