Izvestiya of Saratov University.
ISSN 1816-9775 (Print)
ISSN 2541-8971 (Online)


Phase diagram of the ?-alanine – water binary system

The phase diagram of the ?-alanine–water binary system was studied using the visual polythermal method and the method of time–temperature curves in а temperature range of -20–90°С. There is a eutectic equilibrium at -18.3°С in the system; the solid phases of this equilibrium are ice and individual ?-alanine. For the first time, the composition of the liquid phase of the eutectic state was determined.

Investigation of nikel(II) complexing with 2,6-dimerkapto-4-methilphenol and aminophenols

Complexing of nickel(II) with 2,6-dimercapto-4-methylphenol (DMMP) and hydrophobic amines was studied using physicochemical methods. Hydroxyl-containing amines-aminophenols (AP) were used as a hydrophobic amine. On the part of aminophenols, 2 (N, N-dimethylaminomethyl) -4-methylphenol (AP1 ), 2 (N, N-dimethylaminomethyl)-4-chlorophenol (AP2 ), and 2 (N, N-dimethylaminomethyl) -4-bromophenol (AP3 ) were used. Mixed-ligand complexes were formed in a weakly acidic medium (pHopt 4.6–6.4).

Adsorption of organic reagents by natural bentonites modified with aluminum and iron (III) polyhydroxocations

The effective nanostructured sorbents based on natural bentonite modified with aluminum and iron (III) polyhydroxocations were obtained. The elemental composition of the obtained sorbents was studied. The specific surface area was determined for the studied samples. It was shown that modified sorbents based on natural bentonite were nanostructured objects. IR spectroscopy showed that modification of natural bentonite led to the changes in its structural properties.

Branched polymers of N-isopropylacrylamide: A 2005–2020 review of english literature

The search and the analysis of English scientific literature from 2005 to 2020 devoted to the methods of obtaining branched polymers and copolymers of N-isopropylacrylamide were made in order to obtain novel materials with valuable properties. It was found that modern methods of controlled radical polymerization were mainly used for this purpose, namely, atom transfer radical polymerization (ATRP), polymerization with reversible addition-fragmentation chain transfer (RAFT) and group transfer polymerization (GTP).

“Electronic tongue” multi-systems for the separate determination of cefotaxime and cefazoline

. Electroanalytical properties of unmodified and modified by polyaniline and by CuO nanoparticles solid-contact potentiometric sensors which are based on associates of tetradecylammonium with complex compounds of silver (I) with cephuroxime, cephotaxime and cephazoline Ag(?-lac)2TDA in solutions of corresponding antibiotics were studied. It was revealed that Ag(?-lac)2TDA –based sensors had no specificity to the basic ion but showed sensitivity to other cephalosporins.

Study of the relationship between geometric isomerism and biologically active properties of compounds

The results of the research in the field of studying the relationship of the geometric structure of organic compounds with their biological activity are presented. It has been shown that the stereospecific structure of organic and inorganic molecules can have a direct effect on the biologically active properties of substances. Among the known types of stereoisomerism (geometric and optical), this work summarizes the effect of various types of geometric isomerism on the bioactivity of compounds. In addition, the results of the authors’ own research are presented.

The prospect of using Shewhart control charts in assessing the quality of ionometric measurements by the method of adding a sample to a standar

Modern methods of quantitative physical and chemical measurements should necessarily include procedures for quality control of research results. Recently, the procedure for quality control of measurements using control charts is gaining particular popularity in the practice of analytical measurements. To date, the methods of potentiometric studies operating in the territory of the Russian Federation, in most cases, do not include quality control using this control procedure.

Reuse of a purified solution of cetyltrimethylammonium bromide for the synthesis of gold nanorods

We investigate the possibility of reusing CTAB solutions for repeated synthesis of gold nanorods. Three tasks have been solved. The first task is to clean the growth solutions from gold nanorods. The second task is to develop a method using a purified cetyltrimethylammonium bromide solution for repeated synthesis of gold nanorods with the same optical properties as in the initial synthesis. The third task is to test the possibility of management of the optical properties of nanorods during repeated synthesis.

Study of the diffusion process in films sodium salt of carboxymethyl cellulose – drug

The transport properties of medicinal films based on sodium salt of carboxymethylcellulose and the antibiotic amikacin sulfate have been studied in this work. It has been shown that the process of sorption of water vapor by such films and the release of a drug from them proceeds in an abnormal diffusion mode, which is explained by the slowdown of relaxation processes in glassy polymers, which include the sodium salt of carboxymethylcellulose.

Synthesis and study of some properties of colloidal quantum dots of indium antimonide

Colloidal quantum dots of indium antimonide have been synthesized by a known technique. The shape and average diameters of quantum dots have been investigated by transmission electron microscopy using a transmission microscope. Controlling the size and shape of colloidal QDs provides information on the formation of the crystal structure of nanoparticles and their possible physical and optical properties. It has been found that InSb quantum dots are characterized by a polygonal shape.