DESCRIPTION OF COPPER OR NICKEL CONTAINING MESOPARTICLES USED AS REAGENTS IN REACTIONS WITHOUT CHANGE AND WITH CHANGE OF ELEMENTS OXIDATION STATES (OSS)

In our investigations, it’s established that the metal clusters within metal/ carbon mesoparticles have form near to spheric and are found in carbon shells. The middle size of metal cluster corresponds to 20-30 mn for copper/carbon nanocomposite (Cu/C NC) and 19-20 mn for nickel/carbon nanocomposite (Ni/C NC).

The structures of carbon shells are defined by means of the complex of methods including x-ray photoelectron spectroscopy, transition electron microscopy with high permission, electron microdiffraction (Figures 10.2 and 10.3).

Microphotographs of ТЕМ for Cu/C NC (a) and Ni/C NC (b)

FIGURE 10.2 Microphotographs of ТЕМ for Cu/C NC (a) and Ni/C NC (b).

Cls spectra for Cu/C NC (a) and Ni/C NC (b)

FIGURE 10.3 Cls spectra for Cu/C NC (a) and Ni/C NC (b).

According to Figure 10.2, the carbon structure shells for clusters of copper and nickel have near fonns and are presented as carbon fibers. This fact is confirmed by electron microdiffraction results. In correspondence with Cls spectra (Figure 10.3) the carbon fibers contain the carbine and polyacetylene fragments: peak at 285 eV (C-H bond) and addition to peak at 281-282 eV (carbine).

It’s possible to suppose that the unpaired electrons are found on the joints between carbine and polyacetylene fragments. The stability of formed systems is provided for metal coordination with double bonds, mainly with carbine bonds.

From the comparison of Cls spectra for copper and nickel/carbon NCs the peak C-H bond excess on 30% for Ni/C NC on the relation correspondent peak for Cu/C NC. This result can be explained by the decreasing of carbine fragments in carbon shell of Ni/C NC that is corresponded with incomplete reduction of nickel oxide at the obtaining of this NC (Table 10.1).

TABLE 10.1 Composition of Metal Containing Phases in Metal/Carbon Nanocomposites

Phase

Cu/C Nanocomposite

Ni/C Nanocomposite

CuO

1.17%

-

Cu,0

5.19%

-

Си

93.64%

-

NiO

-

32.15%

Ni

-

67.85%

Therefore the quantity of joints between carbine and polyacetylene fragments for Ni/C NC is bigger than for Cu/C NC, and also unpaired electron excess for Ni/C NC more that is confirmed by EPR spectra: 2.46-1023 spin/g for Ni/C NC and 1.2-1017 spin/g for Cu/C NC.

The presence of unpaired electrons on carbon hells of metal/carbon NCs gives the possibility to the interactions of these mesoparticles with electrofilled chemical substances. Below the mesoparticles interaction reactions with the compounds containing p, d elements are considered. The processes include the reactions without the elements OSs change and reactions with the change of elements OSs.

INTERFERENCE PHENOMENON AT METAL/CARBON NANOCOMPOSITES (NCS) MODIFICATION BY MEANS OF MESOPARTICLES INTERACTION WITH SUBSTANCES CONTAINING P D ELEMENTS

The interaction of metal/carbon nanocomposite (mesoparticle) with polyethylene polyamine (PEPA) and also anmionium iodide (Ami) is studied by IR and x-ray photoelectron spectroscopy. In these cases according to spectra, the nitrogen and iodine addition to carbon shell without change of OSs as well as the absence of metal atomic magnetic moment changes in mesoparticles is observed.

The modification processes of Cu/C NC is carried out by means of the grinding of mesoparticles with reagents (PEPA or Ami) in mechanical mortar longer than 3 minutes.

It’s possible to suppose the following stages:

  • • Mechanical action on the mixture of mesoparticle and reagent initiates unpaired electrons on mesoparticle carbon shell and negative charge quants begin to move in side to positive charged atom of reagent.
  • • Then the increasing of reagent polarization with the negative charge quants flow formation proceeds, and farther the negative charge quants move to opposite flow of mesoparticle negative charge flow.
  • • Then the interference takes place and the following chemical bonds as C-N and C-I bonds are formed.
  • • In parallels the hydrogen from reagent (for instance, PEPA) is added to carbine bonds. Therefore, at the amine group interaction with mesoparticle carbon shell the formation of C=N bond is possible.

The proposed scheme is confirmed by the results of Cls and Nls spectra (Figures 10.4 and 10.5).

In Cls spectrum of Cu/C nanocomposite modified by PEPA the following components as:

C-H (285 eV), C-N (286.4 eV) and C=N (289 eV) are found. It’s necessary to note that the peak at 289 eV has the small intensity. This fact is explained by the small quantity of NH, groups in PEPA because these groups are the ultimate groups in oligomer.

The presence of C-N (398.8 eV) and N-H (397 eV) bonds is observed in Nls spectrum of Cu/C nanocomposite.

The results of Cls and Nls spectra are confirmed the data of IR spectroscopy for samples modified by PEPA. In IR spectra the additional peaks at 1075 and 1268 cm-1 are appeared. These peaks can be relevant to C-N bonds in nitrogen-containing compounds including bonds in the adsorbed PEPA on the surface of Cu/C NC.

Cls spectra ofCu/C nanocomposite modified by PEPA(a) and by Ami (b)

FIGURE 10.4 Cls spectra ofCu/C nanocomposite modified by PEPA(a) and by Ami (b).

Nls spectra of Cu/C nanocomposite modified by PEPA

FIGURE 10.5 Nls spectra of Cu/C nanocomposite modified by PEPA.

 
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