Application of Mass-Spectrometry with laser desorption/ionization for investigation of materials obtained with use of linear acetylenic carbon

Abstract

Linear acetylenic carbon (LAC) is one of the allotropic modifications of carbon, it consists of linear
fragments with a triple bond -C≡C-C≡C-, or cumulated double bond: =C=C=C=C=. LAC is widely used in
medicine and microelectronics. Materials of the anode of electrochemical cells produced with use of linear
acetylenic carbon are studied in the paper. To analyze the quality of application of LAC and the degree of
preservation of such surfaces, mass spectrometry with laser desorption/ionization is used. This method allows
to investigate the initial samples almost without any sample preparation. The patterns of ionization of linear
acetylenic carbon in positive and negative ions are studied. It is shown that in mass spectra of negative ions
of the original LAC, sequence of ions with m/z, which are multiple of 12 Da, could be observed. These ions
are thought to be referred to carbon clusters corresponding to the number of carbon atoms from 2 to 15. At the same time in mass spectra of the anode samples treated by multiple charge-discharge cycles, such clusters
were not observed. It was concluded that during operation of the cell the anode layer of the LAC was destroyed.
At the same time on the surface of the used anode some compounds that make up the components of
the electrochemical cell (porous separator, electrolyte) were found. The results make it possible to create a
technique of express controlling of the quality of coating of various surfaces with LAC, as well as the degree
of preservation of such materials.