Selective ion-exchangers containing phosphorus in their functional groups

1974 ◽  
Vol 21 (1) ◽  
pp. 177-186 ◽  
Author(s):  
M. Marhol ◽  
H. Beranová ◽  
K. L. Cheng
Keyword(s):  
Functional Groups ◽  
Ion Exchangers

Formazans as functional groups of chelating ion-exchangers

1983 ◽  
Vol 316 (2) ◽  
pp. 247-252 ◽  
Author(s):  
M. Grote ◽  
A. Schwalk ◽  
U. Hüppe ◽  
A. Kettrup
Keyword(s):  
Functional Groups ◽  
Ion Exchangers

scholarly journals ENTHALPY OF INTERACTION OF ION-EXCHANGE HETEROGENEOUS MEMBRANES AND THEIR GRANULAR ANALOGUES WITH AMMONIUM NITRATE SOLUTION

2018 ◽  
Vol 59 (7) ◽  
pp. 29
Author(s):  
Sabukhi I. Niftaliev ◽  
Yuriy S Peregudov ◽  
Olga A. Kozaderova ◽  
Kseniya B. Kim
Keyword(s):  
Ion Exchange ◽  
Ammonium Nitrate ◽  
Functional Groups ◽  
Nitrate Solution ◽  
Heat Evolution ◽  
Calorimetric Method ◽  
Anion Exchange Membranes ◽  
Ion Exchange Membranes ◽  
Ion Exchangers ◽  
Ammonium Nitrate Solution

Ion-exchange membranes are widely used for extraction, separation and concentration of aqueous nitrogen-containing solutions. In the study the heterogeneous ion-exchange membranes of cationic type- MK-40, Ralex CM (H) -PP, MK-41 – and anionic type - MA-41, Ralex AM (H) -PP and also their granular analogues – cation exchanger  KУ-2·8 and anion exchanger AB-17·8 were used. Sorption of nitrate ions and ammonium ions was conducted from the ammonium nitrate solution with concentration of 0.012 mole / dm³. To determine sorption thermochemical characteristics of the studied ions the calorimetric method was used. It was found that for all the studied types of membranes and ion exchangers the processes were accompanied by heat evolution. From the calorimetric measurements the thermokinetic interaction curves of cation-exchange membranes and KУ-2×8 with the ammonium nitrate solution and anion-exchange membranes and AB-17×8 with the solution of the same salt were obtained. According to the curves the power of heat evolution and time of the process were determined. It was shown that the ion exchangers KУ-2·8 and AB-17·8 are characterized by a longer time to achieve the maximum of heat evolution and process time than for the similar membranes. This fact is explained by the different number and accessibility of the functional groups in the membranes and ion exchangers. From the thermo-kinetic curves the enthalpies of interaction were calculated. The process of the interaction between the granular ion exchangers and ions is characterized by higher values of the enthalpy than for the membranes which large steric effects are common for. Saline concentration, nature of exchangeable ions and type of functional groups of the ion exchanger and also its moisture content influence the enthalpy value. Experimental calorimetric data indicated that the energy costs connected with the effects of dehydration and conformational changes in the sorbent polymer chains do not overlap the exothermic sorption effect. The calorimetric method is informative to determine the nature and mechanism of sorption.

scholarly journals Bilayer capillary coatings based on nanosized ion-exchangers for the capillary electrochromatography analyses of biogenic amines and amino acids

2021 ◽  
Vol 25 (3) ◽  
pp. 230-240
Author(s):  
D. V. Makeeva ◽  
◽  
D. A. Polikarpova ◽  
L. A. Kartsova ◽  
◽  
...  
Keyword(s):  
Amino Acids ◽  
Functional Groups ◽  
Capillary Electrochromatography ◽  
Cation Exchanger ◽  
Physical Adsorption ◽  
Stationary Phases ◽  
Layer By Layer ◽  
Ion Exchangers ◽  
High Concentration ◽  
Capillary Walls

Nanoparticles are widely used in capillary electrophoresis as stationary phases adsorbed on the internal capillary walls for the separation and concentration of analytes in capillary electrochromatography. The fastest and simplest approach for the formation of coatings is a physical adsorption of nanoparticles. Nevertheless, the formed coatings frequently possess low stability. The layer-by-layer approach for the formation of stabile and dense coating of internal capillary walls based on negatively charged nanosized cation-exchanger was proposed. The method included the sequential alteration of appositively charged layers of nanosized ion-exchangers. The proposed “anion-exchanger – cation-exchanger” bilayer coating possesses high stability in wide pH range (2-10) and provides up to 120 analyses without the need of re-coating. The coating was applied for the separation and on-line concentration of catecholamines and amino acids in capillary electrochromatography mode. High efficiencies were achieved (N = 450-720 th. t.p./m and N = 400-520 th. t.p./m for cathecholamies and amino acids, respectively), while the analysis time was significantly decreased. It was established, that high concentration of negatively charged functional groups on the capillary surface led to the increase of stacking efficiency factors due to the interactions between analytes and functional groups of the modifier on the capillary walls. It contributed to the 2-4 times reduced detection limits (LODs) of analytes compared to the mono-layer coatings (LODs of catecholamines = 3-4 ng/mL, LODs of amino acids = 40-100 ng/mL).

scholarly journals Titration of weak base fibrous anion exchangers in the presence of complex-forming divalent cations

2021 ◽  
Vol 57 (4) ◽  
pp. 391-399
Author(s):  
V. S. Soldatov ◽  
L. N. Shachenkova ◽  
E. G. Kasandrovich ◽  
P. V. Nesteronok
Keyword(s):  
Functional Groups ◽  
Divalent Cations ◽  
Polyacrylonitrile Fiber ◽  
Ion Exchangers ◽  
Polymer Complexes ◽  
Maximum Sorption Capacity ◽  
Wide Range ◽  
Maximum Sorption ◽  
Fibrous Ion Exchangers ◽  
Metal Polymer

Curves of potentiometric titration of fully protonized fibrous ion exchangers with potassium hydroxide against the background of 1 M KCl in the presence of chlorides of Ni2+, Со2+, Сu2+ and Ca2+ were obtained. The ion exchangers were synthesized by modifying of industrial polyacrylonitrile fiber with diethylenetriamine and triethylenetetraamine and predominantly contained functional groups R-CO-NH- (CH2CH2NH)nH (n = 2 or 3) and a small amount of carboxyl groups. The sorption of Ni2+, Со2+, Сu2+ и Ca2+by ion exchangers was calculated from the data obtained depending on the pH of the medium. It was found that the investigated ion exchangers with high selectivity sorb heavy metal ions in a wide range of acidity of solutions (pH 2–9) due to the formation of metal-polymer complexes with polyamine functional groups. The maximum sorption capacity is 1.5–2.7 and 4–5 meq/g for ion exchangers with n = 2 and 3, respectively.

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