To
employ advantageous tunable magnetic properties of metal phthalocyanines
(Pcs) in practical devices it is necessary to bind them to solid substrates.
A simple method to bind Cu(II) and Fe(III) sulfonated phthalocyanines
on a plasma-treated surface of polyethylene (PE) is proposed. Formation
of reactive centers (radicals) on the PE surface after plasma treatment
was observed in electron-spin resonance (ESR) spectra at 330 and
350 mT. The signal at 350 mT disappears after grafting of the Pcs,
which suggests the radical is spent on formation of a chemical bond.
Successful grafting of Pcs was also confirmed by X-ray photoelectron
spectroscopy and SEM-EDS measurements. In UV–vis spectra Q
and B bands typical for the π–π interaction in
Pcs were observed at 620 and 340 nm, respectively. Splitting of the
Q band occurred due to a reduction in the symmetry of the peripherally
substituted Pcs. Interestingly, a lower concentration of CuPc solution
during the grafting process leads to a higher amount grafted to the
surface. In the case of FePc the optimum grafting concentration is
higher. The ESR spectra of PE samples with grafted FePc were similar
to the bulk Pcs with the high-spin state (S = 5/2)
of d5 Fe(III) ions.