Структурно-механічні властивості водних дисперсій пірогенного кремнезему в присутності неіоногенних полімерів

• Datum: 2008
• Hauptverfasser: Goncharuk, E. V., Andriyko, L. S., Malyscheva, M. L., Grutsenko, V. F., Zarko, V. I., Gun'ko, V. M.
• Format: Artikel
• Sprache: Ukrainisch
• Veröffentlicht: Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2008
• Online Zugang: https://surfacezbir.com.ua/index.php/surface/article/view/265
• Назва журналу: Surface

Structure formation in dispersions with nanosilica and non-ionogenic polymers (PVA, PEG, PVP) has been studied using adsorption, rheometry, and electrophysical methods. There are both common and different regularities in the structure formation dependent on the nature of polymers. Extremal polymer concentration dependences are observed for viscosity, turbidity, precipitation volume, and conductivity. The presence of the extremum is due to three states of the structure formation. The first one corresponds to entire adsorption of polymer from the solution and effective formation of bridge bonds between particles. The second is characterized by the presence of both adsorbed and dissolved polymer, and the number of the bridge bonds decreases. Theater corresponds to the maximum polymer adsorption and to increase in the amounts of dissolved polymer that cause enhancement of the system stability observed on transition between the first and second states (at the extremum point) because of the formation of continuous aggregate in the system. Rheological and electrophysical behavior of the silica dispersions with the presence of PEG differs from that for the systems with PVA and PVP due to rheopexy and concentration dependence of conductivity.