Cation exchange compositions

The aim of the present work was optimization of synthesis of SG -polymeric cation exchanger composite films by sol-gel technology in the presence of non-ionic surfactants and their application for detenuination of Zn (II) as phenanthrolinate (Phen) complex. 

M. Hepel, X. M. Zhang, R. Stephenson, S. Perkins, Use of electrochemical quartz crystal microbalance technique to track electrochemiccJly assisted removal of heavy metals from aqueous solutions by cation-exchange composite polypyrrole-modified electrodes. Microchem J 1997, 56 (1), 79-92. 

Ibrahim NA (1992) New cation exchange composite based upon cellulose/melamine form-aldehyde/citric acid reaction products. J Appl Polym Sci 46 829-834... 

SG sols were synthesized by hydrolysis of tetraethyloxysilane in the presence of polyelectrolyte and surfactant. Poly (vinylsulfonic acid) (PVSA) or poly (styrenesulfonic acid) (PSSA) were used as cation exchangers, Tween-20 or Triton X-100 were used as non- ionic surfactants. Obtained sol was dropped onto the surface of glass slide and dried over night. Template extraction from the composite film was performed in water- ethanol medium. The ion-exchange properties of the films were studied spectrophotometrically using adsorption of cationic dye Rhodamine 6G or Fe(Phen) and potentiometrically by sorption of protons. 

SG- PVSA composite film obtained in the presence of Tween 20 possesed the best cation exchange characteristics. The maximum soi ption capacity of SG-PVSA composite film obtained under optimal condition was, mol/g 6,2-10 for Fe (Phen), 2,3T0 for Phodamine 6G and 2,5T0 for protons. The optimal content of PVSA in sol was 4%. 

The chemical adsorption of a relatively high molecular weight neutral polymer (poly(succinimide), M = 13000) on aminopropyl-Vydac 101 TP silica gel was applied by Alpert [47, 48] to prepare a reactive composite support for use in cation-exchange [47] and hydrophobic-interaction [48] chromatography of pro-... 

Metal complexes of chiral bis(oxazoline) ligands, in most cases Cu(II) complexes, have been supported by cationic exchange on inorganic, organic, and composite anionic solids. 

Some properties of the rock used in this study were measured The cation exchange capacity (cec) was determined by the barium sulfate method as described by Mortland and Mellor (33). Surface area was measured by using a Digisorb Meter (Micromeritics Instrument Corporation) through nitrogen adsorption. Estimation of mineral composition and indentification of the rock were performed by X-ray diffraction. 

In order to suppress interferences due to the presence of inorganic species and reliably determine the proteinaceous composition of the sample, a clean-up step has often been introduced in the analytical procedure. This step may include the extraction of the proteinaceous matter by an ammonia solution [8], the use of a cation-exchange resin [8,55], a chelating agent [9,41,44], the use of a Cig resin or the use of barium chloride solution to suppress sulfates [10,81,82]. Table 9.1 reports the methods used to overcome such problems. 

P.C. Meier, W.E. Morf, M. Laubli, and W. Simon, Evaluation of the optimum composition of neutral-carrier membrane electrodes with incorporated cation-exchanger sites. Anal. Chim. Acta 156,1—8 (1984). 

The anion and cation exchange functional groups on the resin are chosen to have high affinity for the salt impurity to be removed (i.e. MX) and a low affinity for the salt product to be left behind. A different resin is generally required for each separation. The exact composition of the resins is proprietary the basic process, however, is the same for each. 

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