Reversible changes in the adhesion of polymers to solid surfaces

The adhesion properties of coatings of polycrystalline hexafluoropropylene—vinylidene fluoride copolymer on steel and glass have been investigated. Coatings formed at 200–240° C suffer a reversible loss of adhesion following the diffusion of water and acid molecules to the interface, which is attributable to the mobile adsorption-desorption nature of the adhesion of this particular copolymer to steel and glass. Heat treatment at 280° C gives the coating improved resistance to the debonding action of water.Ural Scientific-Research Chemical Institute, Sverdlovsk. Moscow Institute of Fine Chemical Technology. Translated from Mekhanika Polimerov, Vol. 4, No. 6, pp. 1065–1070, November–December, 1968.     

Energy spectrum and optical transitions in C80 fullerene isomers

The energy spectra of all isomers of the C₈₀ fullerene have been calculated in terms of the Schubin-Wonsowskii-Hubbard model. On this basis, their optical absorption spectra have also been calculated. The optical absorption spectra calculated for the endohedral Ca@C₈₀, Ba@C₈₀, and Sr@C₈₀ fullerenes with the I _h symmetry agree well with the experimental data. This circumstance allows us to conclude that the optical absorption spectra of other isomers (for which experimental data are unavailable) obtained in this work can be used for their identification.     

Polymer particles containing Fe-based metalloporphyrin as a highly efficient stimulator of reactive oxygen species formation in vitro and in vivo

Russian Chemical Bulletin - Reactive oxygen species are generated by the redox reaction involving metalloporphyrin and ascorbic acid (AA) and lead to oxidative stress followed by cancer cell death....     

Wall shear stress around a stationary gas slug in a downward liquid flow

A single cell of the gas-liquid slug flow was studied. The flow around an immobile gas slug in a downflow of liquid and under its bottom was measured. The values of the wall shear stress and its pulsations were measured by the electrodiffusion method depending on a distance from the slug nose. It is shown that in a liquid film around a slug, turbulent pulsations are damped in comparison with a single-phase liquid flow. In the bottom part of a slug, where vortices are detached, turbulent pulsations exceed significantly the single-phase ones. The work was financially supported by the Russian Foundation for Basic Research (Grant No. 07-08-00405a).     

Polaron States of 3,4-Ethylenedioxythiophene Oligomers

Theoretical and Experimental Chemistry - The electronic and spatial structure of 3,4-ethylenedioxythiophene oligomer containing 12 units (E12) in 0, +1, +2, +3, and +4 charge states has been...     

Mechanical Properties of a Basalt-Fiber-Reinforced Plastic Rod Used in Composite High-Voltage Wires in Torsion and Three-Point Bending

Mechanics of Composite Materials - Results of experimental investigations into a unidirectional composite of basalt fibers and epoxy resin used as part of high-voltage electric wires are presented....