L. Kozhitov, A. Kostikova. V. Kozlov. 7Ji. Myrkhalykov. A. Saipov.
FE A TURES OF FeNi3 NANOPA R TICLES IN POI. YA CR YL0N1TRILE FORMA TION UNDER INF RA RED HEA TING
Fig. 4 - SEM photo for FeNi3/C nanocomposite with initial CFc and Cn, equal to 20 mass % after IR-
heating at 700°C
The elemental analysis of FeNi3/C samples is conducted in the area of the carbon materiał and crystalline FeNi3 (Table 3). It seems that the chlorine content in the carbon materiał is conditioned by non-decomposed metal chlorides. The strong coordination bond between NiCl2 • 6H20 and PAN nitrile group (instability constant of the complex pK=19.11) [15] leads to the high Ni content in the composite therefore CNi= 80.68 and 3.95 mass % in nanoparticles and carbon materiał correspondingly (Table 3).
Table 3 - Elemental content of FeNij/C composite with initial CFe and Cni equal to
20 mass % obtained at 700°C
Ns |
Element |
C, mass % (in the carbon matrix) |
C, mass % (in the nanoparticle) |
1 |
C |
35.24 |
3.77 |
2 |
N |
18.98 |
— |
3 |
O |
7.19 |
— |
4 |
Cl |
15.12 |
1.33 |
5 |
Fe |
19.51 |
14.21 |
6 |
Ni |
3.95 |
80.68 |
In addition to that high concentration Cn, in nanoparticles is explained by Ni reduction easier than for Fe concentration using hydrogen sińce the electrode standard potentials of Ni and Fe are equal to -0.25 and -0.44 V correspondingly. Vice versa the weak coordination bond (pK=7.65) between FeCl3-6H20 and PAN is easily broken. Volatile compound Fe(CO)5 is emitted and the Fe content in the nanocomposite decreases to 19.51 and 14.21 mass % in the carbon materiał and the nanoparticle correspondingly (Table 3). However, CFe =19.51 mass % is larger than CNi =3.95 mass % in the carbon materiał. This promotes to Fe nanoparticle reduction using hydrogen emitted under the polymer destruction (Table 2, sample 2) [15].
To fulfill the control of FeNi3/C nanocomposite content and properties, the thermodynamic analysis of forming metal carbides and metal oxides and the Chemical conversion mechanism in
FeCl3-6H20/NiCl2-6H20/PAN system is required for further investigations under the IR-heating. The economic efficiency is considerably increased by IR-heating using.
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