ИСТИНА

Recently, the problem of microplastics (MP) – polymer particles 5 mm in size or less which are formed during the degradation of plastic waste, has become urgent. Particularly dangerous are particles of submicron size (˂ 1 micron), which can penetrate the biological membranes and cause various negative consequences. In addition to the original MP particles, MP complexes with toxic substances, which include heavy metals, dyes, persistent organic pollutants and polymers with cationic groups (polycations), can be potentially dangerous. The latter are actively used in water purification processes. MP particles with adsorbed polycations can spread over long distances with surface and ground waters. The redistribution of cationic macromolecules between different MP particles increases the number of particles with potentially toxic effects. In the work, the adsorption of cationic polymers on the surface of anionic latex particles modelling real MP particles has been studied. The size (diameter) of latex particles was of 400 nm, their negative charge was due to the surface carboxylic groups. All polymers used were bound quantitatively to the latex particle surface. The binding was accompanied by neutralization of the latex particle charge and aggregation of the resulting complex; the largest aggregates was formed at a complete neutralization of the particle charge by the adsorbed polycation. Reducing the concentration of both components and the molecular weight of the polymer maintained the efficiency of polymer binding to particles and did not lead to particle aggregation. Under these conditions, adsorbed macromolecules were able to migrate between individual latex particles, resulting in a uniform distribution of the polymer between all particles in the system. The results obtained indicate that the migration of adsorbed polymer between particles should be taken into account when discussing the spread of toxic substances.