scholarly journals Structure/function studies of resorcinol-formaldehyde (R-F) and phenol-formaldehyde (P-F) copolymer ion-exchange resins

1996 ◽  
Author(s):  
T.L. Hubler ◽  
J.A. Franz ◽  
W.J. Shaw ◽  
M.O. Hogan ◽  
R.T. Hallen ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Structure Function ◽  
Phenol Formaldehyde ◽  
Ion Exchange Resins ◽  
Resorcinol Formaldehyde ◽  
Exchange Resins

Deactivation of Spent Ion-exchange Resins Contaminated by Cesium and Cobalt Radionuclides

2019 ◽  
Vol 23 (4) ◽  
pp. 20-24
Author(s):  
M.S. Palamarchuk ◽  
E.A. Tokar ◽  
M.V. Tutov ◽  
A.M. Yegorin
Keyword(s):  
Iron Oxide ◽  
Ion Exchange ◽  
Liquid Radioactive Waste ◽  
Formaldehyde Resin ◽  
Ion Exchange Resins ◽  
Resorcinol Formaldehyde ◽  
Circulating Water ◽  
Cesium Radionuclides ◽  
Edta Complexes ◽  
Exchange Resins

Simulation of iron oxide (magnetite and maghemite) and aluminosilicate (sillimanite and cyanite) deposits formed on the surface of spent ionexchange resins in the process of decontamination of liquid radioactive waste contaminated by cesium and cobalt radionuclides has been performed. A method of deep deactivation of spent ion-exchange resins contaminated by aluminosilicate and iron oxide deposits using alkaline and acidic solutions containing Zn-EDTA complexes has been suggested. The method of two-stage concentrating of cesium radionuclides using selective sorption materials (resorcinol-formaldehyde resin and Thermoxid-35 ferrocyanide sorbent) has been improved. The method advantage consists in using a solution containing EDTA complexes for elution of cesium radionuclides from the resorcinol-formaldehyde resin with their transition onto Thermoxid-35. High stability of the resorcinol-formaldehyde resin and Thermoxid-35 in the course of concentrating has been demonstrated. A scheme of deactivation of spent ion-exchange resins, which enables one to decrease the volume of secondary wastes due to utilization of a circulating water supply, has been suggested.

scholarly journals Effect of the Resorcinol/Formaldehyde Ratio and the Temperature of the Resorcinol–Formaldehyde Gel Solidification on the Chemical Stability and Sorption Characteristics of Ion-Exchange Resins

Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 239
Author(s):  
Eduard Tokar ◽  
Mikhail Tutov ◽  
Pavel Kozlov ◽  
Arseni Slobodyuk ◽  
Andrei Egorin
Keyword(s):  
Ion Exchange ◽  
Chemical Stability ◽  
Model Solution ◽  
Alkaline Media ◽  
Molar Ratio ◽  
Ion Exchange Resins ◽  
Solidification Temperature ◽  
Resorcinol Formaldehyde ◽  
Exchange Resins ◽  
Sorption Characteristics

A series of resorcinol–formaldehyde resins (RFR) samples for Cs-137 removal from liquid alkaline media have been synthesized. It has been demonstrated that the chemical stability as well as sorption characteristics are determined by the resorcinol/formaldehyde molar ratio and the solidification temperature. It has been also demonstrated that the sample synthesized at the resorcinol/formaldehyde molar ratio of 1.8/2.2 and solidified at 210 °C is characterized by the best sorption-selective characteristics and chemical stability. Under dynamic conditions, at feeding >1000 bed volumes of a model solution with pH > 13, the RFR 3-1 goes through six sorption cycles without noticeable changes in the sorption characteristics. The results are presented that demonstrate the possibility of RFR application in the decontamination of real LRW from Cs-137.

Embedding Procedure for Water Swollen Samples

1970 ◽  
Vol 28 ◽  
pp. 504-505
Author(s):  
Ann M. Thomas ◽  
Virginia Shemeley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Exchange ◽  
Structural Changes ◽  
Cross Linking ◽  
Ion Exchange Resins ◽  
Transmission Electron ◽  
First Pass ◽  
Exchange Resins

Those samples which swell rapidly when exposed to water are, at best, difficult to section for transmission electron microscopy. Some materials literally burst out of the embedding block with the first pass by the knife, and even the most rapid cutting cycle produces sections of limited value. Many ion exchange resins swell in water; some undergo irreversible structural changes when dried. We developed our embedding procedure to handle this type of sample, but it should be applicable to many materials that present similar sectioning difficulties.The purpose of our embedding procedure is to build up a cross-linking network throughout the sample, while it is in a water swollen state. Our procedure was suggested to us by the work of Rosenberg, where he mentioned the formation of a tridimensional structure by the polymerization of the GMA biproduct, triglycol dimethacrylate.

Applications of Ion Exchange Resin in Oral Drug Delivery Systems

2017 ◽  
Vol 7 (03) ◽  
Author(s):  
Kathpalia Harsha ◽  
Das Sukanya
Keyword(s):  
Drug Delivery ◽  
Ion Exchange ◽  
Drug Delivery Systems ◽  
Oral Drug Delivery ◽  
Physical Stability ◽  
Delivery Systems ◽  
Oral Drug ◽  
Ion Exchange Resins ◽  
Exchange Resins ◽  
Oral Drug Delivery Systems

Ion Exchange Resins (IER) are insoluble polymers having styrene divinylbenzene copolymer backbone that contain acidic or basic functional groups and have the ability to exchange counter ions with the surrounding aqueous solutions. From the past many years they have been widely used for purification and softening of water and in chromatographic columns, however recently their use in pharmaceutical industry has gained considerable importance. Due to the physical stability and inert nature of the resins, they can be used as a versatile vehicle to design several modified release dosage forms The ionizable drug is complexed with the resin owing to the property of ion exchange. This resin complex dissociatesin vivo to release the drug. Based on the dissociation strength of the drug from the drug resin complex, various release patterns can be achieved. Many formulation glitches can be circumvented using ion exchange resins such as bitter taste and deliquescence. These resins also aid in enhancing disintegrationand stability of formulation. This review focuses on different types of ion exchange resins, their preparation methods, chemistry, properties, incompatibilities and their application in various oral drug delivery systems as well as highlighting their use as therapeutic agents.

THE DISPOSAL OF USED ION EXCHANGE RESINS

2004 ◽  
Vol 3 (3) ◽  
pp. 447-455
Author(s):  
Viky Dicu ◽  
Carmen Iesan ◽  
Mihai Chirica ◽  
Satish Bapat
Keyword(s):  
Ion Exchange ◽  
Ion Exchange Resins ◽  
Exchange Resins

FTIR ANALYSIS OF ION EXCHANGE RESINS WITH APPLICATION IN PERMANENT HARD WATER SOFTENING

2014 ◽  
Vol 13 (9) ◽  
pp. 2145-2152 ◽  
Author(s):  
Liliana Lazar ◽  
Laura Bulgariu ◽  
Bogdan Bandrabur ◽  
Ramona-Elena Tataru-Farmus ◽  
Mioara Drobota ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Hard Water ◽  
Ion Exchange Resins ◽  
Ftir Analysis ◽  
Water Softening ◽  
Exchange Resins
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