Vol 92, No 4 (2023)
Articles
Selective recovery and recycling of lithium: prospects for the use of membrane methods
Abstract
In recent years, the interest of researchers in the problem of lithium extraction (production) has increased due to the drastic increase in its demand: according to the Scopus database, about 3000 scientific articles were published on this problem in 2021. The efforts of many specialists are aimed at the development of new, more economical and environmental-friendly membrane technologies for lithium extraction, replacing the reagent methods used. This review presents up-to-date information about traditional and promising methods of lithium recovery from natural solutions and solutions obtained during recycling of used batteries. The main attention is paid to membrane methods. Known approaches are classified and analyzed, experimental and theoretical aspects of Membrane Ion Separation are described, and known separation mechanisms and their mathematical models are discussed. Baro- and electromembrane methods relatively well developed at the laboratory level are considered, which are focused on the separation of lithium ions and other single-charged cations from mixed solutions containing large amounts of magnesium and calcium. The results of using commercial and laboratory membranes are compared. The newest approaches, which allow efficient separation of lithium ions from a mixture of single-charged cations, including the promising hybrid electrobaromembrane methods, are analyzed. Bibliography — 295 references.
Uspehi himii. 2023;92(4):RCR5074
RCR5074
Nanocellulose and its polymer composites: preparation, characterization, and applications
Abstract
Natural and synthetic polymeric materials are in high demand that continues to increase year after year, making them essential part of human life. By employing cellulose and cellulose derivatives as fillers for either synthetic or natural polymers, the environmental impact of non-biodegradable materials can be reduced. Nanocellulose (NC) materials have recently gained a lot of interest as potential fillers for reinforcing polymeric materials. The article highlights the different sources of NC, including plant sources, marine algae, bacteria and sea animals. The use of dewaxing solvents, alkali, bleaching agents, enzymes, 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO), ammonium persulfate (APS), ionic liquids, deep eutectic solvents and steam explosion for pretreatment of lignocellulosic materials was explained. In addition, this review considers the extraction methods, including mechanical fibrillation for the production of cellulose nanofibers (CNF) and acid hydrolysis for the production of cellulose nanocrystals (CNC). Furthermore, the article discusses recent advances in the fabrication of NC polymer composites, such as the melt mixing process, solution casting, 3D printing, electrospinning and pickering emulsions methods. The different characterization techniques of NC polymer composites were discussed in this article. Many promising applications of NC polymer composites, such as sensors, electronics, fuel cells, construction, paper and board, biomedical, food packaging, water purification, aerogels, and hydrogels are considered. Bibliography — 299 references.
Uspehi himii. 2023;92(4):RCR5076
RCR5076
Recent advances in the chemistry of two-carbon nitro-containing synthetic equivalents
Abstract
To date, nitro-containing compounds form one of the most important classes of organic compounds. The chemistry of these molecules attracts attention primarily due to their use as high-energy reagents and drugs. Also, the introduction of a nitro group is a popular synthetic strategy for constructing new organic molecules. The present review summarizes the latest research findings of compounds bearing a nitro group on a two-carbon moiety such as aminonitroethylenes, α,α-bis(alkylsulfanyl)nitroalkenes and their amino derivatives, α-nitroketones, alkyl nitroacetates and nitroacetonitrile. The literature data are systematized according to the type of chemical reactions such as reactions between nucleophiles and electrophiles, various cyclization reactions, reactions at the C–H bond, etc. The reactivities of the said nitro compounds and the conditions of chemical transformations are compared to assess the prospects of their application. Bibliography — 314 references.
Uspehi himii. 2023;92(4):RCR5077
RCR5077