Doklady Chemistry

An approach to molecular nanotubes of a new type based on bisthiacalix[4]arene with ethylene sulfide bridges in cone stereoisomeric form has been suggested and implemented. This ligand has shown selective liquid-phase extraction of Ag+.

Conceptual and mathematical formulations were developed for the problem of optimizing the chemical and energy engineering process (CEEP) of drying of a moving dense multilayer mass of phosphorite pellets in a complex chemical and energy engineering system (CEES)—travelling grate machine—as a discrete dynamic programming problem. A criterion of the efficiency of the drying CEEP was taken to be the minimum of the cost of the heat and power consumed in the drying CEEP. The obtained results of solving the optimization problem were applied to calculate the characteristics of the energy efficiency of the drying of pellets in the CEES. It was determined that, under the optimal conditions of the drying of the moving multilayer mass of pellets, there is no overmoistening zone, the heat- and moisture-transfer processes are intensified, the power consumption reduces, and the quality of the final product increases.

The results of a study of migration of electrically conductive nano-sized carbon particles of different types to the surface of molten polymer composite are presented. The real-time measurements of the changes in electrical conductivity of the polymer composite melt at a constant temperature, carried out separately for the bulk and surface conductivity components, revealed the basic features of the process. The results indicate that the formation of a surface layer saturated with electrically conductive nanoparticles is a general phenomenon for composites where filler nanoparticles with different aspect ratios are used. The role of polymer macromolecules in the kinetics of migration of carbon nanoparticles to the polymer composite melt surface is discussed.

Hybrid nanoparticles based on Fe3O4 and CdS combining magnetic and luminescence properties were synthesized. The possibility of visualization of various cells by 3-mercaptopropylsilane-modified CdS nanoparticles and hybrid nanoparticles based on them using a confocal microscope was demonstrated. The synthesized materials did not show a clear-cut cytotoxicity.

The radical polymerization of 2,3,4,5,6-pentafluorostyrene (PFS) in the presence of poly-2-hydroxyethyl methacrylate with a dithiobenzoate end group as a chain transfer agent was studied in DMF-d7 in situ by 1H NMR spectroscopy. It was found that the reaction has virtually no induction period and proceeds at a higher rate than PFS polymerization in the presence of a low-molecular-weight chain transfer agent. A possible reason for the observed kinetic features is the self-assembly of PFS and 2-hydroxyethyl methacrylate diblock copolymers during the polymerization.