Adsorption of polyvinylpyrrolidone and polyoxyethylene by pure and mixed silicon, aluminium and titanium oxides

Adsorption of polyvinylpyrrolidone (PVP) and polyoxyethylene (POE) from the aqueous solutions onto surfaces of individual and mixed silicon, titanium and aluminium oxides was studied. It was found that the values of polymer adsorption depend on composition of oxides. It was shown with IR spectroscopy that the surface of the oxides studied is fully accessible to interaction with PVP and POE

Геометричне та механо-сорбційне модифікування високодисперсного кремнезему в умовах газового дисперсійного середовища

Methods of geometric and solvate-stymulated mechano-sorption-activated modification of fumed nanosilica in the gaseous dispersion media were developed and used to prepare functionalyzed nanofillers for polymeric systems. Non-volatile high- and low-molecular weight compounds (such as polymers, organic bioactive compounds, organic and inorganic salts) can be used as modifiers of nanofillers.Були описані геометричне та сольвато-стимульоване механосорбційне модифікування високодисперсного кремнезему в умовах газового дисперсійного середовища. Такі способи модифікування дозволяють одержувати функціоналізовані наповнювачі полімерних систем на основі нанорозмірного кремнезему. Для модифікування можна використовувати нелеткі високо- та низькомолекулярні органічні сполуки – полімери, біологічно активні сполуки, органічні солі, а також неорганічні солі

Adsorption and Migration of Poly(Vinyl Pyrrolidone) at a Fumed Silica Surface

A series of poly(vinyl pyrrolidone) (PVP)/fumed silica powder samples were studied using adsorption, FT-IR and AFM methods. Mild treatment (293 K for several hours) of PVP/A-300 powder with an added additional portion of A-300 in a glass reactor (2 dm 3 ) using a mixer (> 500 rpm which provided the powder as a pseudo-liquid state, PLS) led to the redistribution (migration) of the PVP molecules between silica particles previously covered by PVP and free of PVP. This time-dependent rearrangement of the adsorbed PVP molecules caused the formation of a denser polymer layer at the silica surface. The aggregate size of the primary silica particles with adsorbed PVP molecules decreased after treatment. The volume of macropores with a pore radius R p > 25 nm increased due to the decrease in the distances between aggregates in agglomerates because of the adhesive effect of the PVP molecules. However, the volume of micropores at R p < 1 nm decreased because of the penetration of the PVP molecules into the primary silica particle aggregates and the filling of gaps between adjacent particles. A decrease occurred in the amount of adsorbed water in the PVP layer exhibiting a maximum density