| Abstrakt: |
Being released into the environment, the nanosized particles are present in it in the form of a colloid. At the same time, the colloid has an ability to change its properties, including its dimensionality, depending on the physical conditions, as well as composition of the dispersing medium. Nevertheless, this circumstance is irrelevant when assessing the risk associated with the spread of nanosized particles in the environment. The conditions under which the colloid retains its property of nanoscale dimensionality are of fundamental importance for a reliable assessment of the risk associated with the spread of nanosized particles. The aggregate stability, determined by the forces of physical interaction (Van der Waals force and capillary force) was used in the study as the main criterion for the preservation of the nanometric dimensionality of the colloid. The nanosized copper oxide particles, due to their high degree of distribution, as well as the most mobile environmental media, namely air and water, were identified as the subject of the study. It was found that when the distance between copper oxide particles amounts to 400 nm or less, they form aggregates in the specified environmental samples. The attractive force between copper oxide particles in the air is 3 times higher on average than in water. Yet, being in an aqueous medium, the copper oxide particles form clusters connected by liquid bridges, the contact interaction radius of which is 12–30 nm at a capillary force of 0.86–3.34 J. The study proves that when assessing the risk associated with the migration of particles in environmental samples, it is necessary to take into account their physical interaction. [ABSTRACT FROM AUTHOR] |
