SELECTIVE SORBENTS BASED ON DIAMINODICYCLOHEXYLCROWN ETHERS

Курманалиев Мусрепбек Курманалиевич, Несипхан Абжапарович Бектенов, K.A. Sadykov

2023

Closed access Metadata (CSL-JSON)
DOI 10.51580/2023-1.2710-1185.06
Data confidence 70 medium
How this score is calculated

It is built from checkable properties of the record itself: whether the article has a DOI, how many independent sources confirmed its data, whether the required fields are filled in, and how recent the latest confirmation is. Disagreement between sources and a missing identifier lower it. A value of 80 or above means the record was published without further checking; 60 to 79 means it is published at reduced confidence, with a manual check advisable. A record verified by an editor by hand is never pushed below 90 by a recalculation. This scores our data about the article, not the article itself.

Abstract

Macromolecules with crown ether groups are a fundamentally new type of sorbents whose active centers are ligands that retain electrical neutrality in the process of simultaneous binding of cations, anions, or organic compounds. The purpose of this work is to create new selective sorbents based on diaminodicyclohexylcrown ethers and to study their complexing properties with respect to alkali metal ions. Methodology. To study the composition and properties of the products of the synthesis of crown ether-containing sorbents, chemical and physicochemical methods of analysis were used: infrared spectroscopy, atomic absorption spectrophotometry. Results and discussion. Chemical grafting of cycloaliphatic crown ethers onto a macroporous chloromethylated copolymer of styrene and divinylbenzene has been carried out. Under the chosen conditions, when using diaminodicyclohexyl-18-crown-6, polycrown ethers were obtained with a content of crown ether grains of 1.42 mmol/g, when using diaminodicyclohexyl-24-crown-8, the content of macrocyclic groups was 1.24 mmol/g. The extraction of alkali metals under static conditions by grafted sorbents based on various macrocycles has been studied. The high values of the distribution coefficients of alkali metals (Na+, K+, Cs+) by the synthesized sorbents in an acidic medium are shown. The following selectivity series were found for the sorbent with diaminodicyclohexyl-18-crown-6 fragments: K+ ˃ Cs + ˃ Na+, and for the sorbent with diaminodicyclohexyl-24-crown-8 fragments: Cs+ ˃ K+ ˃ Na+ metals. Conclusion. The efficiency of extracting metal ions from aqueous solutions containing Crown esters is affected by the presence of amino groups. It is known that the amino group promotes the formation of a polymer that swells in water. It was noted that the use of sorbents based on polymers that swell in water when metal salts are removed from the aqueous medium leads to an increase in the sorption capacity of sorbents by facilitating the access of metal ions in water to the active areas of the immobilized sorbent.