The regularities of obtaining silver nanoparticles in the presence of polyvinylpyrrolidone, which was both a reductant and a stabilizer of nanoparticle dispersion, have been studied. The influence of such factors as temperature, polyvinylpyrrolidone amount, concentration and nature of silver salts on the shape and size of nanoparticles has been established. The chemistry of the silver salts and polyvinylpyrrolidone reaction with the formation of vinylsuccinimide units in the structure of macromolecules has been proposed, which is confirmed by the results of IR spectroscopy.
The influence of technological factors on the regularities of obtaining silver nanoparticles using polyvinylpyrrolidone as reducing agent has been researched and its influence in compositions content on antimicrobial properties of last ones have been defined. The impact of temperature and polyvinylpyrrolidone content as well as Ag+ concentration on the kinetics of the reduction reaction of silver ions was determined. Silver-containing composites in the form of porous blocks and films were synthesized and their bactericidal and fungicidal properties were studied.
A new mechanism for the reaction of direct (additive) chlorination of ethylene with chlorine from the formation of 1,2-dichloroethane in the presence of FeCl3 catalyst promoted by NaCl has been proposed. It was found that the rate depends on the active phase concentration of the catalyst and the promoter, as well as the formation of the Na[Fe(C2H4Cl)4] complex, which is a surface intermediate of the reaction.
Article is devoted to the research of the influence of the sodium salt of perfluoro sulfonic acid, as a stabilizer, on the catalytic activity of iron chloride and sodium chloride in the reaction of direct chlorination of ethylene to 1,2- dychloroethane. During research authors found that increase of stabilizer concentration up to 4% mas. had no significant impact on the catalytic activity of the complex but increase from 4% mas. up to 10% mas. allowed to shorten time of dissolution of sodium chloride and to reach needed concentration of sodium ions in the reactor of direct chlorination.
The influence of stabilizers – hydrogen donors – on the processes of thermooxidative destruction of pitch-based polymer has been investigated. It is shown that Irganox has not stabilizing effect on pitch-based polymer and melamine slightly retards the destructive process. A mixture of melamine and Irganox exhibits synergetic stabilizing effect and at the optimum ratio it can be used to prevent unwanted thermooxidative processes during pitch-based polymer preparation.
The operation of hopper devices, which are used in industry, civil engineering, agriculture and transport, is analyzed on the article. The external factors, which influence the process of charging, storing and discharging of loose cargo (freights) from hopper tanks, are overviewed. The subject of research of presented paper is the improvement of mechanisms of fracturing of products hangs-up (bridges) in hoppers at the stage of designing and setting up of hopper devices.
The influence of composite component perlite DPh-Zn, that is the waste of oil refining industry, on the formation of properties complex of rubber mixes and their vulcanizates on the basis of apolar cis-1,4-polyisoprene and butadiene-nitrile rubbers of various polarity has been investigated. It has been established that perlite DPh-Zn is the effective vulcanization active component of multifunctional action capable at 10.0 mass frac.
The procedure of emulsion preparation with hydrocolloids which are stabilizer-emulsifiers, namely gum-arabic and starch, was updated by introducing new technological parameters, such as oil : aqueous phase ratio, sequence and parameters of ingredients introduction, parameters of pre-emulsion preparation and homogenization. The food emulsion samples were investigated using different amounts of gum-arabic and starch at constant amount of oil phase and samples with variable amount of oil phase and constant amount of a stabilizer.
This review briefly gives the status of worldwide researches in the aspect of an impact of incorporated fullerenes and carbon nanotubes (CNTs) on durability of different polymeric composites under stressful harsh therm-oxidative conditions. It has been inferred that among various nanoparticulates, fullerenes and CNTs are preferable to be used for enhancing thermal and mechanical properties of polymers.