Features Of Particle Size Measurements In The Nanosilica Hydrosol By The Optical Methods

2016 ◽  
Vol 11 (4) ◽  
pp. 68-77
Author(s):  
Konstantin Zobov ◽  
Vyacheslav Syzrantsev ◽  
Sergey Bardakhanov
Keyword(s):  
Particle Size ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Rayleigh Scattering ◽  
Light Transmission ◽  
Light Attenuation ◽  
Optical Methods ◽  
Medium Size ◽  
Small Scale ◽  
Transmission Electron Microscopy Analysis

The current level of study and application of nanoparticles raises the question of their classification. One of the main parameters in this case is the particle size. However, its measurement on such a small scale is a valuable problem as usual models are not correct. The article presents the results of measurements of the light attenuation in the hydrosols (dispersions of nanoparticles in water). The Rayleigh scattering theory was applied to the experimental data for obtaining the average size of nanoparticles with various specific surfaces. The obtained values were compared with the results of the transmission electron microscopy analysis and with the results of dynamic light scattering measurements. All of measurements variants presented the specified value of medium size. It could be caused by the mechanics characteristics, structure and other properties of nanoparticles related to the surface properties and their production process. The Rayleigh theory gave the undervalued particle size, and dynamic light scattering gave overvalued one in a comparison with the microscopy data. It is shown that the light transmission attenuation strongly depends from the particle size, only for particles bigger than 15 nm. For smaller particles the association was not found. There are two different particle size ranges for dynamic light scattering measurement of different produced particle.

Optical Properties of Aggregated Magnetic Fluid: Birefringence and Light Scattering

2015 ◽  
Vol 233-234 ◽  
pp. 314-317
Author(s):  
Constantine V. Yerin
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Size Distribution ◽  
Magnetic Moments ◽  
Optical Methods ◽  
Colloidal Solutions ◽  
Magnetite Particles ◽  
Nanosized Magnetite

The optical properties of colloidal solutions of nanosized magnetite particles in kerosene were studied by optical methods (birefringence and light scattering). The data on the birefringence kinetics in nonstationary magnetic fields is used to determine the size distribution of magnetite particles and aggregates. It is shown that the particle size distribution essentially depends on the type of magnetic moments of the particles and aggregates. Static and dynamic light scattering experiments confirm the conclusion about the existence of a significant fraction of nanoparticles in the form of aggregates with sizes of several tens of nanometers.

scholarly journals Modulation of Lithium Disilicate Translucency through Heat Treatment

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2094
Author(s):  
Seok-Ki Jung ◽  
Dae Woon Kim ◽  
Jeongyol Lee ◽  
Selvaponpriya Ramasamy ◽  
Hyun Sik Kim ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Light Scattering ◽  
Flexural Strength ◽  
Control Method ◽  
Light Transmission ◽  
Lithium Disilicate ◽  
Lower Heat ◽  
Average Size ◽  
Ball Test

The aim of this study was to present a control method for modulating the translucency of lithium disilicate ceramics through thermal refinement. Identical lithium disilicate blocks were thermally refined using four different heat treatment schedules, and the microstructure, translucency, and flexural strength of the ceramics were investigated in detail by SEM, spectroscopy, and a piston-on-three-ball test. The results showed that ceramics treated under higher heat had larger grains, with an average size between 240 and 1080 nm. In addition, a higher transmittance of all wavelengths was observed in ceramics treated under lower heat, and the transmittance in the 550 nm wavelength ranged from 27 to 34%. The results suggest that the translucency of ceramics can be modified through thermal refinement under two conditions: (1) the particle size of the ceramic is small enough to achieve minimal grain-boundary light scattering, and (2) the percentage of particles allowing visible light transmission is altered by the heat treatment.

scholarly journals Multiple-Penalty-Weighted Regularization Inversion for Dynamic Light Scattering

2018 ◽  
Vol 8 (9) ◽  
pp. 1674
Author(s):  
Wengang Chen ◽  
Wenzheng Xiu ◽  
Jin Shen ◽  
Wenwen Zhang ◽  
Min Xu ◽  
...  
Keyword(s):  
Particle Size ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Simulated Data ◽  
Bimodal Distribution ◽  
Scattering Data ◽  
Inversion Algorithm ◽  
Penalty Term ◽  
Peak Resolution ◽  
Time Period

By using different weights to deal with the autocorrelation function data of every delay time period, the information utilization of dynamic light scattering can be obviously enhanced in the information-weighted constrained regularization inversion, but the denoising ability and the peak resolution under noise conditions for information-weighted inversion algorithm are still insufficient. On the basis of information weighting, we added a penalty term with the function of flatness constraints to the objective function of the regularization inversion, and performed the inversion of multiangle dynamic light scattering data, including the simulated data of bimodal distribution particles (466/915 nm, 316/470 nm) and trimodal distribution particles (324/601/871 nm), and the measured data of bimodal distribution particles (306/974 nm, 300/502 nm). The results of the inversion show that multiple-penalty-weighted regularization inversion can not only improve the utilization of the particle size information, but also effectively eliminate the false peaks and burrs in the inversed particle size distributions, and further improve the resolution of peaks in the noise conditions, and then improve the weighting effects of the information-weighted inversion.

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