INFLUENCE OF NANOCOMPOSITE FILMS FRACTALITY ON POLYETHYLENE ABSORPTION WITH FULLERENE C60

In this article the results of experimental studies of fractal nature influence of the carbon nano-additives of fullerene C60 on the structure and properties of a low-density polyethylene (LDPE) are presented. The introduction of fullerene nano-additives into the LDPE matrix leads to an increase in the absorption properties, particularly the optical density of the system. The different electronic structure of the matrix of polyethylene and fullerene C60 shows different contribution of absorption abilities of one or another sample either in the short-wave or long-wave regions of the spectra presented in this work. Meanwhile, the low degree of conjugation in the low-density polyethylene matrix may affect absorption in the shorter-wavelength region of the spectrum at higher energies, while the absorption in the long-wavelength region may be due to allowed optical transitions in the C60 fullerene molecule. The intermolecular interaction in the considered sample system, occurring as a result of mutual exchange between the highest occupied molecular orbital of the donor (LDPE) and the lowest unoccupied molecular orbital of the acceptor (fullerene C60 molecule), arising due to the overlapping π-orbitals of the molecules of both reacting substances in the studied matrix, influences on the character of the investigated spectral features. The red shift of the absorption peaks in the corresponding spectra may be due to the change in the electronic structure of polyethylene caused by the interaction between fullerene and the aromatic ring of the polymer matrix of polyethylene. The analysis of the dynamics of changes in the fractal dimension of the low-density polyethylene-fullerene C60 system showed a possible gradual aggregation of fullerene molecules in the polyethylene matrix. The increase of fractal dimension of the studied samples with increasing concentration of fullerene nano-additives leads to a possible connection of interaction, subsequent aggregation of C60 molecules with electronic transformations in the spectral dependences. Keywords: low-density polyethylene, fullerenes, fractal dimension, aggregation.