Sorption of Eremomycin on Carboxylic Cation Exchangers

The relationships of sorption of antibacterial antibiotic eremomycin on carboxylic cation exchangers were studied. The difference between gel-like and structurally segregated carboxylic cation exchangers were analyzed by potentiometric titration. The optimal conditions for sorption and desorption of eremomycin were found.     

Epichlorohydrin-Based Polyfunctional Ion Exchangers

Polyfunctional polyelectrolytes were synthesized by polycondensation of epichlorohydrin oligomer in the presence of allyl bromide. The polycondensation conditions were optimized, and composition and the properties of the resulting ion exchangers were studied.     

Compact and Low-Cost Heat Exchangers for an Undergraduate Laboratory

The construction and operation of low-cost concentric double-tube heat exchangers is presented. These exchangers occupy little laboratory space due to their compact and portable design. Water taken from the laboratory mains is used as cooling fluid and flows in the shell side of exchanger. Hot fluid, which circulates in the tube side, is water supplied by a domestic electric heater. Flow rates are measured with flow meters and temperatures with thermocouples connected to a computer. Second-year undergraduate students of chemistry have been satisfactorily working with these exchangers for two years. Experimental data and calculated results from students are shown. Overall and film heat-transfer coefficients are determined. The main goal of the experimental described is to examine the heat transfer between incompressible fluids in the steady state.     

Comparative Study of Water Softening with Granular and Fibrous Ion Exchangers

Comparative study of softening of model hard water with both strongly acidic fibrous FIBAN K-1 and granular KU-2 ion exchangers was carried out. The influence of the filter-bed height, packing density of fibrous ion exchangers, volume sorption capacity, and filtering rate on the efficiency of calcium removal from model hard water was analyzed.     

Ceramic Cation Exchangers in Ion-Exchange Chromatography

The kinetics of attainment equilibrium in sorption and desorption of sodium and potassium ions with foam ceramic cation exchangers with chemically bound phosphate and vanadate groups was studied.     

含磺酸,羧酸双功能基树脂对混合氨基酸的分离性能研究

对苯乙烯-丙烯腈-二乙烯基苯(S/AN/DVB)交联共聚机理研究曾发现,丙烯腈作为第三单体,可使DVB竞聚率比在S/DVB共聚体系中降低,相互分离显著,从而有利于合成性能较好的离子交换树脂;本文在此基础上,将S/AN/DVB共聚体中的氰基水解成羧基来合成含磺酸、羧酸双功能基树脂,解决了前人研究中仅有50％的氰基水解成羧基的问题,并首次将这种树脂应用于混合氨基酸的分离。     

Sorption Behaviour of Molybdenum on Different Antimonates Ion Exchangers

Various antimonate compounds are well known as important inorganic ion exchangers, since they resist radiation and chemical degradation and also exhibit selectivities towards different cations. Ceric, silicon, titanium and ferric antimonates were prepared as inorganic ion exchangers. Characterization of these materials has been described using different techniques, including thermal analysis, surface area measurements, X-ray diffraction and IR-spectroscopy. In batch distribution experiments the influence of HNO₃ molarity and Mo concentration for Mo sorption on different matrices is described in terms of their retention capacities and distribution coefficients.The selectivities of these exchangers towards molybdenum are in the order: CeSb > SiSb > FeSb > TiSb.     

农副产品制备纤维素强阴离子交换剂

阴离子染料;脱色;农副产品制备纤维素强阴离子交换剂     

Composite Ion Exchangers Based on KU-23 and KM-2P Cation Exchangers and Nickel(III) Hydroxide and Their Use for Purification of Nickel Sulfate Solutions To Remove Cobalt(II) Impurity

A method of preparing composite ion exchangers based on macroporous cation exchangers and nickel(III) hydroxide was developed, and their suitability for deep purification of nickel(II) sulfate solutions to remove small amounts of cobalt(II) was demonstrated.     

Synthesis and Physicochemical Study of Polyfunctional Ion Exchangers Based on Dextramine Waste from Levomycetin Production

New polyfunctional anion exchangers are synthesized from dextramine (waste from levomycetin production) by condensation of its glycidyl ethers with certain polyamines. The polycondensation conditions are optimized, and physicochemical properties of the resulting ion exchangers are studied.     

Inorganic Ion Exchangers for Cesium Removal from Radioactive Wastewater

Ion exchange is a proven process for radioactive wastewater decontamination, where inorganic sorbents are ideal due to their thermal, chemical and radiation stability. This review focuses on the removal of Cs⁺ by inorganic exchangers, viz. zeolites, titanosilicates, hexacyanoferrates metal oxides and hydrous metal oxides, bentonite/clays and the key family of ammonium phosphomolybdates (AMPs). The design of new selective composites is also addressed focusing on those based on AMPs, hexacyanoferrates and titanosilicates/zeolites. Future inorganic Cs⁺ exchangers will encompass promising solids, like lanthanide silicates, sodium titanates and metal sulfides. The sensing ability derived from the photoluminescence properties of lanthanide silicates and the efficiency of layered gallium-antimony-sulfide materials in acidic and basic solutions disclose considerable potential for real applications. The ion exchange systems are discussed in terms of sorbent capacity and selectivity (with competitors), pH, temperature and solution salinity. The microscopic features of the exchangers and the associated mechanisms (e.g., pore size, counterions radii, dehydration energy of the ions, coordination environments in the solid exchanger, and site accessibility) are always used for interpreting the ion exchange behavior. On the whole, more than 250 publications were reviewed and a large compilation of data is provided in Supplemental Material.     

沸石交换剂的不完全交换反应热力学

本文深入研究了不完全交换反应热力学,提出了新的观点,讨论了前人的有关理论。     

Polyfunctional Anion Exchangers Based on Copolymers of Allyl Glycidyl Ether and Polyamines

Polyfunctional anion exchangers were prepared by copolymerization of allyl glycidyl ether with polyamines in the presence of a promoter. The synthesis conditions were optimized. The composition and physicochemical features of the resins prepared were studied.     

Chromatography of Uranium on High-Performance Ion Exchangers

Abstract

The potential of high-performance liquid chromatography (HPLC) for the determination of U(VI) in ground waters and urine has been examined under a variety of HPLC experimental conditions. Conventional cross-linked and bonded-phase ion exchangers, both cation and anion, were studied with aqueous mobile phases containing tartrate, citrate, or α-hydroxyisobutyrate. The best chromatography was obtained on bonded-phase cation exchangers with an α-hydroxyisobutyrate eluent. The metal ions were detected either by visible spectrophotometry after a post-column reaction with a complexing reagent, or with a polarographic detector. Dectection after post-column reaction gave the best sensitivity; the detection limit (2 × baseline noise was 6 ng or 60 ng.ml^?1 for 100 μl samples. In-line trace enrichment was used to decrease detection limits and linear calibration curves were observed in the ranges studied; 0.5 to 50 ng.mL^?1 for ground waters and 25 to 400 ng.mL^?1 for artificial urine.     

Anion Exchangers Based on Allyl Compounds and Some Nitrogen- and Oxygen-Containing Monomers and Oligomers

Anion exchangers containing different basic groups and having good physicochemical and sorption properties were prepared by polycondensation of polyallylamine and various allyl halides, diglycidyl ethers of dihydroxybenzenes, and aromatic amines with some aliphatic polyamines.     

Preparation of Phosphoric-Carboxylic Cation Exchangers from Wood Cellulose

Phosphorus-containing cellulose cation exchangers were synthesized by reaction of wood cellulose with orthophosphoric acid and the ternary polymer from glycidylmethacrylate, styrene, and maleic anhydride. The effects of the ratio of reactants, temperature, and duration of the reaction on the phosphorylation and exchange capacity of the modified cellulose material were studied.     

Sorption of Vanillin by Highly Basic Anion Exchangers under Dynamic Conditions

Russian Journal of Physical Chemistry A - Features of the dynamic extraction of vanillin from aqueous solutions using highly basic anion exchangers with a gel or macroporous structure are studied....     

Selective Recovery of Nonferrous Metal Cations from Wastewater with Weakly Basic Anion Exchangers

Selective recovery of transition metals (Ni^{2 +}, Cu^{2 +}, and Cr^{2 +}) with weakly basic anion exchangers from aqueous solutions simulating naturally mineralized water was studied. The exchange capacity of anion exchangers for these cations was determined. The technique for efficient resin regeneration was developed.     

Sorption of Nickel Ions from Aqueous Solutions by Ion Exchangers

Sorption of Ni²⁺ions from aqueous solutions by ion exchangers differed in their chemical nature and structure was studied. Based on the endothermic curves of ice melting obtained by a differential scanning calorimetry, the amounts of freezing and non-freezing water present in free volumes (pores) of the studied ion exchangers were calculated. Comparison of results obtained from the kinetic curves of nickel ion sorption with data on differential scanning calorimetry indicates a role of structural factor in the sorption of nickel ions. It was found that, depending on the total amount of freezing and non-freezing water, the KU-2-8 sulfonated cationite is the most preferable ion exchanger for the sorption of nickel ions from aqueous solutions. Therefore, sorbent efficiency in this case is determined by its structure rather than by chemical nature.     

Anion Exchangers Based on Glycidyl Derivatives of Aromatic Diamines and Some Allyl Halides

Polyfunctional three-dimensional network anion exchangers were prepared by condensation of tetraglycidyl-4,4'-diaminodiphenylmethane with allyl halides and amines. The optimal preparation conditions were determined; the properties of the resulting product as influenced by the nature of the initial monomers were evaluated.