Characterization of electrocatalytic proton reduction and surface adsorption of platinum nanoparticles supported by a polymeric stabilizer on an ITO electrode

Platinum nanoparticles (PAA-Pt) stabilized by polyacrylic acid (PAA) of a polymeric stabilizer were adsorbed on an indium tin oxide (ITO) surface from their colloidal solution due to the chemical adsorption...

Application of Vinyl ether Copolymers for Surface Modification of Carbon Black

In this work, the possibility of stabilizing aqueous dispersed systems of carbon with vinyl ether copolymers of various composition and structure was investigated. It was shown that the presence of hydrophobic fragments in the macromolecule chain plays a significant role and positively affects the results of stabilization of aqueous dispersions of carbon particles. It was shown that the composition and molecular architecture of the stabilizing copolymer strongly affects the stabilizing ability in studied systems. Studies have shown that the use of a polymeric stabilizer in combination with ultrasonic treatment of dispersed systems makes it possible to obtain stable, homogeneous, highly dispersed suspensions. At the same time, it was demonstrated that a strong increase in the time and intensity of ultrasonic treatment of the system does not lead to a significant improvement in the results

How Does the Addition of Kollidon®VA64 Inhibit the Recrystallization and Improve Ezetimibe Dissolution from Amorphous Solid Dispersions?

Amorphization serves as a strategy for the improvement of poor dissolution characteristics of many drug compounds. However, in many formulations the content of polymeric stabilizer is high, which is undesirable from the perspective of future applications. Thus, studying the composition-dependent stability of amorphous solid dispersions seems to be demanded. In this paper, we describe the amorphization of ezetimibe, a lipid-lowering drug, in the spray drying process and investigate the effect of polyvinylpyrrolidone-co-poly(vinyl acetate) (PVP/VA) content on the physical stability and dissolution characteristics of the drug. Fully amorphous systems were obtained when the concentration of the polymer in solid dispersion was as low as 20%. The amorphization led to the dissolution enhancement by even 70%, with a noticeable sudden increase at around 40% of PVP/VA content and very small variations for systems having 66–90% PVP/VA. It was also correlated to wettability characteristics of solid dispersions, which may suggest that in the vicinity of 40% of the polymer content, the behavior of the system becomes independent of the PVP/VA content.

Black phosphorus with near-superhydrophobic properties and long-term stability in aqueous media

We present the use of a polymeric stabilizer which stymies the degradation of black phosphorus nanosheets in aqueous media as well as imparting superhydrophobic properties to immobilised nanosheets.