On Polymer Nanocomposites - Progress in Organic and Physical Chemistry: Structures and Mechanisms - page 229

characterized by such important parameters, as Mo(d) -position of maximum (a dis-
tribution mode), <d> V -average size of crystalline particles based on volume of the
sample (the average arithmetic size) and Me(d) -the median of distribution de¿ ning the
size d , specifying that particles with diameters less than this size make half of volume
of a powder.
The results represented on Figure 2, show that initial powders nc-Si in the structure
has particles with the sizes less than 10 nm which especially effectively absorb UV
radiation. The both powders modes of density function of particle size are very close,
but median of density function of particle size of a powder nc-Si-36 it is essential more
than at a powder nc-Si-97. It suggests that the number of crystalline particles with
diameters is less 10 nm in unit of volume of a powder nc-Si-36 much less than in unit
of volume of a powder nc-Si-97. As a part of a powder nc-Si-36 it is a lot of particles
with a diameter more than 100 nm and even there are particles more largely 300 nm
whereas the sizes of particles in a powder nc-Si-97 do not exceed 150 nm and the basic
part of crystalline particles has diameter less than 100 nm.

FIGURE 2 Density function of particle size in powders nc-Si, received from x-ray
diffractogram by means of program PM2K.
(ɚ) - nc-Si-97 Mo(d) = 35 nm Me(d) = 45 nm <d> V = 51 nm;

(ɛ) - nc-Si-36 Mo(d) = 30 nm Me(d) = 54 nm <d> V = 76 nm.