Signal and Data Processing

Dispersion of nanoparticles in nanostructures is one of the most important indicators designed to verify the effectiveness of proposed methods in the synthesis of nanomaterials. In the recent years, various methods have been suggested for the synthesis of nanostructures in which the Scanning Electron Microscopy (SEM) has been used to show the quality of the nanomaterial. The SEM images of nanoparticles contain structural, chemical and morphological information with high resolution in nanometer scale of nanomaterials.
One of the challenges in the quality of dispersion’s nanostructures is detection of agglomeration degree. In some SEM images of nanoparticles, the particles have speeded uniformly and not aggregately. In some of the other SEM images, their particles are agglomerated. Also, there are a few SEM images of nanoparticles that their particles aren’t very aggregate or diffused. If the SEM images of nanoparticles with their particles speeded uniformly, are called good images, and the images with their aggregate particles are called bad images, and the images with their particle dispersion between good and bad images, are called average images, the nanomaterials could be classified in categories of good, average, and bad images.
In this paper, a new algorithm has been provided to classify nanostructures using SEM images of nanoparticles. For this purpose, these images were transformed to time series at first (the time series extracted are unique for each SEM image of nanoparticles) and their specifications were investigated through time series analysis methods. Then, statistical specifications of these series were extracted. Six statistical specifications have been extracted for classification of nanostructures. These specifications are as follows: standard deviation, first and second kurtosis, interquartile range, the criterion of Pearson, and skewness. The extracted specifications were used as inputs of a fuzzy inference system for classifying microscopic images of nanostructures into three groups: good, average and bad. This algorithm has been tested on 65 nanoparticles microscopic images with identical size and resulted precision above 93 percent indicated validity of this algorithm.