3D Quantitative Light-intensity Dispersion Index of Polymer Nanocomposites Based on Optical Microscopy

There is a great demand for a dispersion evaluation method that can be applied even when a nano-sized filler is incorporated, that can evaluate a three-dimensional (3D) quantitative dispersion of a composite material, and that is not expensive and time consuming. Here, we proposed light-intensity dispersion index (LDI) to quantitatively evaluate the dispersion based on the light scattering distribution on divided optical microscopy (OM) images. Difference in the light-intensity is determined by the dispersion and agglomeration of the filler in the polymer matrix; therefore, the smaller the distribution and the number of peaks of light-intensity, the more uniform the dispersion. The reliability of the developed LDI was improved by introducing an agglomeration size weighting factor. Furthermore, the validity of the LDI was also verified in comparison with the experimental results. In conclusion, we have successfully developed a method for the 3D quantitative dispersion evaluation of nanocomposites with minimal cost and time consumption.