Estimation of particle size distribution from cross-sectional particle diameter on the cutting plane (original) (raw)

Effects of Angular Dependency of Particulate Light Scattering Intensity on Determination of Samples with Bimodal Size Distributions Using Dynamic Light Scattering Methods

Nanomaterials (Basel, Switzerland), 2018

The angular dependency of light scattering intensity from differently sized particles strongly influences the apparent particle size distribution, as determined by dynamic light scattering (DLS) methods. Manufactured nanomaterials have size distributions more or less; therefore, the effect of detecting the angular dependency of the apparent size distribution by DLS is crucial. Commercial DLS instruments typically have two different types of detector angular position. The first is a detector angled at 90°, and the other is a backscattering angle detector. We therefore investigated the coverage and angular dependency when determining the relative concentrations of nanoparticles in polystyrene latex samples with a bimodal size distribution, using DLS methods both experimentally and theoretically. We used five differently sized polystyrene latex particles (one was a 70-nm nanoparticle and the others were various submicron-sized particles) in a variety of mixtures (the ratio of the diffe...

Influence of the Angular Light Scattering Measurement Uncertainly on the Particle-Size Distribution

2007

The determination of the spherical particle-sizes in colloidal suspension by Angular Light Scattering presents a lot of advantages, i.e.: the relative simplicity of the experimental installations, and its non-destructive character. The intensity of the scattered light is related with the radius of a particle by Mie Theory. However, the dynamic characteristic of the measurements establish a variations of the scattered intensity with the time which it has not considered. In the case of the particle suspended in water, the intensity of the scattered light measured in each angle θ is the superposition of the scattered intensity for each particle. In consequence, the intensity of the light scattered will be related with a particle-size distribution function, that in this work is assumed as a δ function.

Comparison of Particle Size Distributions Measured Using Different Techniques

Particulate Science and Technology, 2005

In this article, particle size distributions (PSDs) measured by different techniques, including image analysis (IA), laser diffraction (LD), ultrasonic attenuation spectroscopy (UAS), and focused-beam reflectance measurement (FBRM), are compared for spherical glass beads and nonspherical silica flakes. It is shown that particle shape strongly affects the results obtained by different techniques. For spheres, the PSDs obtained by IA, LD, and UAS agree well. There is no consistent result among different particle measurement techniques for nonspherical particles. The conversion between PSDs obtained by IA, LD, and UAS has been based on particle shape factors. Caution must be exercised when a measured chord length distribution (CLD) is used to indicate the PSD during a process because the CLD result obtained by FBRM is complex, depending not only on the PSD, but also on particle optical properties and shape. Keywords Particle size distribution (PSD), image analysis (IA), laser diffraction (LD), ultrasonic attenuation spectroscopy (UAS), focused-beam reflectance measurement (FBRM), chord length distribution (CLD)

Measurement of particle sizes by elastic and quasi-elastic light scattering

Biochimica et Biophysica Acta (BBA) - Protein Structure, 1975

A method of measuring an average particle radius in a highly polydisperse dispersion using the wavelength dependence of turbidity is described. For particles which are no larger than 0.3 of the wavelength of light used, a polynomial representation of the scattering cross-section can be used. For larger particles, more extensive numerical calculations are required.

Commercial spectrophotometer for particle sizing

Applied Optics, 1997

Particle-size distribution and the concentration of polystyrene particles suspended in water were accurately recovered from the inversion of spectral extinction data measured with a commercial spectrophotometer. The instrument was modified by placing a spatial filter in the collection optics to prevent low-angle scattered light from affecting the measurement of transmitted power. The data were inverted by use of a nonlinear iterative algorithm. When the extinction coefficient is measured in the range of 0.3-1.1 m, the particle distributions can be retrieved over a diameter range of 0.6 -2.8 m for a wide interval of sample concentrations. The average diameters are recovered with a precision of better than Ϯ1% and with accuracies consistent with the uncertainties by which the nominal diameters are known. The relative standard deviations of distributions corresponding to monodisperse samples are Ϯ5-10%, whereas the accuracy on the measured concentrations is ϳ5%.

Quantification of particle size and concentration using in-line techniques and multivariate analysis

Powder Technology, 2020

We study means of extracting quantitative information about particle attributes using state-ofart in-line and off-line particle measurements and analysis techniques. The approach comprises a combination of image analysis, laser diffraction, inversion of chord length distribution, and multivariate analysis. Polystyrene particle suspensions are used as the model system to provide a wide range of particle loadings (up to 10 wt%), sizes (<90 to 800 µm) and shapes. We identify key challenges and limitation of the in-line imaging and chord length measurements; particularly, an upper limit of particle number density of 10,000 g-1 is observed, as well as the impact of internal reflections from large and transparent particles. The latter phenomena deteriorate the accuracy of the chord length distribution and the subsequent particle size estimation using inversion algorithms. The study demonstrates the use of multivariate analysis 2 for quantifying particle size and concentration, which yields relative errors of 6 and 11 %, respectively.

Particle size distribution quantification by microscopic observation

Journal of Aerosol Science, 2004

The particle size distributions measured by the optical microscope (OPM) were compared with those by the light scattering particle counter (PC) to validate the microscopic method for particle size distribution quantiÿcation. While the OPM concentrations increased with the PC concentrations, the OPM concentrations tended to be higher than those by the PC. To explain the di erence between the two methods, we estimated their relationship based on the Mie scattering theory. The calculation roughly estimated the particle geometric diameters in theory were 1.7-2.0 times as large as the corresponding PC readouts. Using these theoretical factors, the size ranges of the PC were converted to match with the OPM measurements (PC * ). Overall, the OPM concentrations were lower than the PC * concentrations. The advantage in the OPM method particularly for ambient aerosols lied in its accuracy of particle sizing although the counting e ciency might be lowered due to its intrinsic limitations such as inability of counting particles having the similar refractive index of the ÿlter. ?