The action of functional groups of an ion exchanger during its use as a solid catalyst

1976 ◽  
Vol 41 (5) ◽  
pp. 1282-1287 ◽  
Author(s):  
K. Setínek ◽  
Z. Prokop
Keyword(s):  
Functional Groups ◽  
Ion Exchanger ◽  
Solid Catalyst

Sorption of Lead by the Selective Ion Exchanger Ostsorb DETA

1992 ◽  
Vol 57 (7) ◽  
pp. 1393-1404 ◽  
Author(s):  
Ladislav Svoboda ◽  
Jan Uhlíř ◽  
Zdeněk Uhlíř
Keyword(s):  
Phosphoric Acid ◽  
Aqueous Solutions ◽  
Functional Groups ◽  
Ion Exchanger ◽  
Preconcentration Procedure ◽  
Bead Cellulose

The properties of Ostsorb DETA, a selective ion exchanger based on modified bead cellulose with chemically bonded diethylenetriamine functional groups, were studied, and its applicability to the preconcentration of trace amounts of lead from aqueous solutions was verified. The conditions of the preconcentration procedure in the column and batch modes were optimized for this purpose. The results obtained were applied to the determination of lead in phosphoric acid.

Kinetic properties of the chelating derivatives of spheric cellulose

1986 ◽  
Vol 51 (9) ◽  
pp. 1903-1909 ◽  
Author(s):  
Věnceslava Tokarová ◽  
Oldřich Tokar ◽  
Jaromír Kareš
Keyword(s):  
Diffusion Coefficient ◽  
Functional Groups ◽  
Total Mass ◽  
Steric Effect ◽  
Ion Exchanger ◽  
Substantial Decrease ◽  
Exponential Dependence ◽  
Kinetic Properties ◽  
Sorption Rate ◽  
Derivatives Of

The steric effect of the functional groups on the kinetic properties of the chelating cellulose ion exchanger OSTSORB SALICYL is demonstrated. The exponential dependence was found between the diffusion coefficient and the concentration of the ion-exchanging functional groups and, together with its total mass capacity and its content of water, it has been used for the estimation of the sorbent kinetic properties. Moreover, the results obtained show that the attempt to achieve the highest possible capacity of the ion exchanger can lead to a substantial decrease of the sorption rate.

Application of Chelating Ion Exchanger Ostsorb DTTA to Determination of Lead and Cadmium in Soils, Plants, and Fertilizers

1994 ◽  
Vol 59 (3) ◽  
pp. 558-568 ◽  
Author(s):  
Ladislav Svoboda ◽  
Miloslav Tomek ◽  
Petr Tolar
Keyword(s):  
Functional Groups ◽  
Ion Exchanger ◽  
Plant Materials ◽  
Lead And Cadmium

The paper investigates a possible application of chelating cellulose ion exchanger with the functional groups of diethylenetriaminetetraacetic acid to concentrating lead and cadmium in extracts from soils and industrial fertilizers or mineralizates of plant materials. A favourable recovery of the metals needs the knowledge of the approximate content of the complex forming cations in the solutions and the suppression of formation of iron and aluminium hydroxides during modification of acidity of extracts to the value of pH 4 which is the optimum for the formation of chelates. The degree of concentrating reached the values of fE = 10 - 50, the recovery of lead and cadmium depended on the nature of sample and was in the range of R = 60 - 100%.

Preparation, characterization and application of an cellulose ion-exchanger with acetoacetamide functional groups

1985 ◽  
Vol 322 (5) ◽  
pp. 491-494 ◽  
Author(s):  
G. Dietz ◽  
T. Seshadri ◽  
H. -J. Haupt ◽  
A. Kettrup
Keyword(s):  
Functional Groups ◽  
Ion Exchanger

Environmentally Friendly Nafion-Mediated Friedländer Quinoline Synthesis under Microwave Irradiation: Application to One-Pot Synthesis of Substituted Quinolinyl Chalcones

Synthesis ◽  
2020 ◽  
Vol 52 (12) ◽  
pp. 1779-1794 ◽  
Author(s):  
Cheng-Chung Wang ◽  
Chieh-Kai Chan ◽  
Chien-Yu Lai
Keyword(s):  
Microwave Irradiation ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Functional Groups ◽  
Chemical Method ◽  
Solid Catalyst ◽  
Synthetic Route ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray

An efficient and eco-friendly synthetic route for Friedländer quinoline synthesis of polysubstituted quinolines is described. This green chemical method starts from various 2-aminobenzophenones and mono- or dicarbonyl synthons and uses reusable Nafion NR50 material as a solid catalyst in ethanol under microwave irradiation. The protocol has a high generality of functional groups and provides the desired quinolines in good to excellent yields. Some structures were confirmed by single-crystal X-ray diffraction analysis.

Sorption of Cadmium and Lead by Chelating Ion Exchangers Ostsorb DITHIZON and Ostsorb SALICYL

1994 ◽  
Vol 59 (6) ◽  
pp. 1319-1325 ◽  
Author(s):  
Ladislav Svoboda ◽  
Stanislav Jech
Keyword(s):  
Salicylic Acid ◽  
Ionic Strength ◽  
Aqueous Solutions ◽  
Functional Groups ◽  
Exchange Capacity ◽  
Ion Exchanger ◽  
Alkaline Media ◽  
Ion Exchangers ◽  
Metal Concentrations ◽  
Cadmium And Lead

The pH and I (ionic strength) dependences of exchange capacity of chelating ion exchangers Ostsorb based on spherical cellulose modified with functional groups of dithizone and salicylic acid have been studied in the sorption of Pb(II) and Cd(II) ions. The cellulosic selective sorbents Ostsorb DITHIZON and Ostsorb SALICYL can be used for sorption of Pb(II) and Cd(II) ions from aqueous solutions of I = 0 - 1 mol l-1 (Pb) and I = 0 - 5 mol l-1 (Cd); the dithizone ion exchanger retains both metals most effectively at pH 7 - 8, the salicyl ion exchanger at pH 5.5 - 6.5 (Pb) or pH 4 - 9 (Cd). Because of the formation of precipitates of hydrolytic products of the two metals in neutral and alkaline media, it is suitable to carry out the sorption in media of mild acidity if possible, particularly so at the metal concentrations above 1 mg l-1. Increasing ionic strength affects the exchange capacity for both metals in a negative way.

Organic ion exchangers with enhanced catalytic activity

1982 ◽  
Vol 47 (6) ◽  
pp. 1613-1620
Author(s):  
Zdeněk Prokop ◽  
Karel Setínek
Keyword(s):  
Catalytic Activity ◽  
Functional Groups ◽  
Ion Exchanger ◽  
Ion Exchangers ◽  
Styrene Divinylbenzene

Several methods aimed at increasing the catalytic activity of the sulphonated styrene-divinylbenzene macroporous ion exchanger Wofatit OK 80 have been tested. The activity of the prepared ion exchanger catalysts has been examined in three reactions of different type which allowed to examine the effect of the methods used in the broader range of conditions. The results obtained show that the catalytic activity of ion exchangers can be increased substantially either by increasing the total number of acid functional groups, or, particularly, by such treatment which makes the maximal number of the present functional groups accessible to reaction components. However, by the chemical procedures used to enhance the activity, the ion exchangers acquire frequently also some properties which affect negatively their application as catalysts.

Effect of Crosslinking Time on Ion Exchange Capacity of Polystyrene Nanofiber Ion Exchangers

2012 ◽  
Vol 506 ◽  
pp. 437-440 ◽  
Author(s):  
T. Nitanan ◽  
Prasert Akkaramongkolporn ◽  
Theerasak Rojanarata ◽  
Tanasait Ngawhirunpat ◽  
Praneet Opanasopit
Keyword(s):  
Sulfuric Acid ◽  
Controlled Release ◽  
Ion Exchange ◽  
Cation Exchange ◽  
Functional Groups ◽  
Crosslinking Agent ◽  
Exchange Capacity ◽  
Ion Exchanger ◽  
Ion Exchangers ◽  
Ion Exchange Capacity

In this study, polystyrene nanofiber ion exchangers (PSNIE) were successfully prepared by a new method comprising of electrospinning and the subsequent crosslinking with formaldehyde and sulfonation in sulfuric acid to create the cation exchange functionality on the fibers surfaces. The PS solution at 15% w/v in dimethylacetamide (DMAc) produced the smallest PS nanofibers (399±38 nm) with good performance. The degree of crosslink and ion exchange capacity (IEC) of PSNIE depended upon the crosslinking time. The longer crosslinking time caused the greater crosslinked PS fibers. At the longest crosslinking time of 75 min, the remaining crosslinked PS fibers in dichloromethane were 94.12%; whereas, the starting fibers completely dissolved. This crosslinking agent (e.g. formaldehyde) might introduce methylene bridges in addition to sulfone bridges into the fibers. However, IEC decreased as crosslinking time increased, probably due to the difficulty of sulfonic functional groups to react with crosslinked PS fibers. The PSNIE crosslinked for 10 min showed the maximum IEC of 2.86 meq/g-dry-PSNIE, and the diameter of the PSNIE after sulfonation increased to 450-460 nm. Since cationic drug could be loaded onto this novel PSNIE, this nanofiber ion exchanger may be applied for controlled release delivery.

Improving integration between functional groups: A case in organization change and implications for theory and practice

1971 ◽  
Author(s):  
Warren G. Bennis ◽  
Michael Beer ◽  
Gerald R. Pieters ◽  
Alan T. Hundert ◽  
Samuel H. Marcus ◽  
...  
Keyword(s):  
Functional Groups ◽  
Organization Change ◽  
Theory And Practice
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