INDEX metal particle size distribution

More realistic and complex tlieories consistent with the quite complex nature of the phenomena involved in the DR of light were developed later. Experimental studies have shown that this technique is affected by particle size, granulometric distribution and the refractive index of the particles, which has an important role when the particle size is near the wavelength of the 1R radiation. Diffuse reflectance Fourier transform (DRIFT) studies in the FIR region allow detection of the skeletal spectra of materials, such as mixed oxide catalysts, pigments and metal halides. 

Computerized techniques are sometimes employed for cost/performance evaluations. The particle shape, size and distribution, oil absorption, dispersibilty and impurities of fillers affect its performance. Use of fillers with fine particle size and a refractive index closer to PVC results in the least reduction of clarity. Surface gloss decreases with coarse types and higher loadings cause whitening. Surface treated fillers are more easily dispersed. The presence of heavy metal impurities such as iron or zinc are avoided since they cause thermal degradation of PVC. 

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