Polymer gel/organic dye complexes in aqueous salt solutions

The present work is devoted to the study of the complex formation of polyme r gel with organic dye and their properties in the aqueous salt solutions. Two systems were studied: 1) polyelectrolyte gel based on poly(diallyldimet hylammonium chloride) and water soluble oppositely charged organic dyes (al izarin red S and catechol violet) and 2) organogel based on poly(N-vinylcap rolactam) and dithizone. The collapse of the polyelectrolyte gels in the pr esence of oppositely charged dyes together with the effective absorption of dyes was observed. The shrinking degree and the dye absorption by the gel depends on the dye concentration. In the case of PVCa gel in organic media the dye absorption takes place. The main attention has been concentrated on the study of the behaviour of g el/dye complex immersed in the salt solution if dye is the chelating ligand for metal ions. It was shown that polyelectrolyte gels generally form stab le complexes with oppositely charged dyes. The behaviour of PVCa-dirhizone-chloroform system was studied in AgNO3 aque ous solution. The release of dithizone to the external aqueous solution of AgNO3 reservoir is completely suppressed. Absorption spectra of gel/dye and gel/dye/metal ion systems were studied. I t was shown that metal ions penetrate inside the gel phase and the dye/meta l ion complexes form within the gel. The dependence of the optical density for the systems of gel/dye/metal ion on the salt concentration is observed.