SEM image processing of polymer nanocomposites to estimate filler content

To study the distribution of morphological structures like fillers (such as silica nanoparticles) and their agglomerates in polymer nanocomposites, image processing technique on 2D scanning electron microscopy (SEM) image of the polymer nanocomposites was used. A suitable algorithm was proposed to determine the threshold for binarization of the SEM image. The algorithm also gave an estimate of filler percentage in the nanocomposites. With the help of an independent experiment using Thermogravimetry Analyzer (TGA), the silica (filler) contents of the nanocomposites were estimated. The results obtained using image processing technique were in good agreement with the experimental results obtained through thermogravimetry analysis. The binary images thus definitely depicted the acceptable distribution of the nano-fillers and their agglomerates in the nanocomposites.