Development of method for determining antioxidant activity of extracts based on deep eutectic solvents.

Antioxidant activity is an important characteristic of plant extracts. One of the methods to determine it, is the phosphomolybdate method, which is based on the formation of a water-soluble colored complex and the spectrophotometric determination of its concentration. Recently, methods for obtaining plant extracts using deep eutectic solvents (DES), consisting of two or more substances, have been actively developed. Many DES contain choline chloride. The presence of choline chloride makes it difficult to determine the antioxidant activity of DES-based extracts by the phosphomolybdate method since an insoluble complex is formed during the reaction. The aim of this work is to modify the phosphomolybdate method for determining the antioxidant activity of DES-based extracts by adding acetone to the mixture to transfer the resulting complex into solution.

Ubiquity of complex coacervation of DNA and proteins in aqueous solution

Complex coacervation follows the signature pathway defined by the onset of formation of interpolymer complex at rc, soluble complex at rφ, and insoluble complex at rprecip.

THE USE OF SALTS OF D-METALS OF THE 4th PERIOD AS COAGULANTS IN THE PRODUCTION TECHNOLOGY OF EMULSION RUBBERS

Currently, much attention is paid to improving the technology of rubbers obtained by emulsion polymerization. The stage of isolation of rubber from latex is one of the problematic stages of this production. The development of more advanced coagulating systems remains relevant. For the first time, the possibility of using d-metal salts of the fourth period of the periodic table of Mendeleev’s salts as coagulants in rubber isolation is considered: chloride of zinc, nickel and cobalt. The influence of the consumption of these salts on the completeness of rubber isolation is investigated, the properties of rubbers are estimated. It is found that zinc chloride has the best coagulating ability. The formation of insoluble complex compounds between the coagulating agent and surfactants of the latex system is established. It is revealed that the acidification of the coagulating system leads to the release of higher carboxylic acids in free form and the formation of sulfuric salts of zinc, cobalt and nickel, which remain in the aqueous phase (serum). The presence of these salts in the serum allows its usage in the technological process of emulsion rubbers production for the preparation of aqueous solutions of chlorides of these salts, as well as acidifying agent (sulfuric acid). The positive outcome of the considered issues contributes to the solution of a number of environmental problems. The studied rubber mixtures and vulcanizates prepared on the basis of experimental rubbers meet the regulatory requirements.

Design of a Device to Eliminate Isocyanuric Acid from Water

This paper shows the design of a device for partial eliminating of isocyanuric acid (ICN) from swimming pool water using melamine additives. The renewal process of swimming pool water through its own purification makes absolutely necessary the elimination of isocyanuric acid that has been accumulated in the water over time. An excess of isocyanuric acid in water will then prevent chlorine effectiveness in the pool water and as a result, becomes harmful to human health. Therefore, the disinfection stage is considered as well as Isocyanuric acid (ICN) stabilization and as doing this is achieved through melamine-photometry filtering of insoluble complex ICN-M. The overall objective of these stages of purification is to eventually eliminate ICN from swimming pool. The overall objective of this device is to eventually eliminate ICN from swimming pool and then make it safe for human uses, a case that has been considered viable technologically and economically in the system treatment.