Study On Measurement Of Submicron And Nanometer Particle Based On The Fractal Of Scattering Light Signal

With the special characters in electrics, magnetic, photics and acoustics, submicron and nanometer particle has wide applications in many fields such as chemical, medicine, national defense, etc, so the measurement is very important. Currently, the Photon Correlation Spectroscopy (PCS) is the widely used measurement, but the equipment is expensive, and it is used in research generally. In the industry of the preparation of nanometer particle, the measurement is the urgent needed which is low-cost, simple and speeded. This dissertation studied on the measurement of submicron and nanometer particle based on the fractal of scattering light signal, the main researches are as following:1. Based on light scattering theory, the fluctuation of the scattered light was analyzed and the fractal characterization of the scattering light signal was investigated.2. Based on the analysis of structural parameters, a particle sizing apparatus was developed, and a temperature control device was designed to meet constant temperature requirement of the sample cell.3. Experiments with particles of different diameters were carried out under 18,20,22,24,26,28,30℃, the fractal dimensions of scattering light signal were computed, and the influences of temperature were researched. Conclusion can be obtained that the higher the temperature, the bigger the fractal dimensions for particles of the same diameter.4. The corresponding relationship of diameters from 50nm to 480nm and fractal dimension under temperatures from 18℃to 30℃was acquired.5. When the temperature was 26℃, particles with different diameters were measured with sampling points of 512,1024,2048,4096,8192,16384,32768,65536. And the results indicated that when the sampling points are more than 16384, the repeatability and relative error of the results were smaller than 2%.6. Particles with different diameters were measured when the temperature were 18,20,22,24,26,28,30℃, the repeatability and relative error of the results were analyzed. And finally this measuring method was compared with the PCS.Compared with PCS, the measurement which this dissertation studied is low-cost, its amount of sample data is small, the data processing method is simple, and it is easy to realize on-line measurement.