Anion exchanger polyvinyl

Selective ion electrodes (SIE). Selective ion electrodes are essentially variants of the well-known pH meter. They are membrane indicator types of electrodes in which a potential is developed across a membrane in the presence of the ion the size of the potential is related to the concentration and hence can be used to quantitatively detect and measure the species. However, instead of a glass membrane, as in the pH meter, the membranes consist of organics that are immersible in water. For example, anion-sensitive electrodes use a solution of an anion exchange resin in an organic solvent the liquid can be held in the form of a gel, for example, in polyvinyl chloride. The ion reacts with the organic membrane, setting up an equilibrium between the free ion in solution and the ion bound to the membrane, generating a potential difference, which is measured. 

Matrex PAE-300 (silica based, polyethyleneimine coated weak anion exchange, 10 fi particles) Polyvinyl sulfonic acid (2 kD) Ovalbumin, conalbumin 29... 

Granular anion-exchange resins have been prepared from N-containing C-vinyl heterocyclics, polyvinyl compounds and one or more aliphatic vinyl compounds in an aqueous phase in presence of water-insoluble suspension stabilizers Thus, a mixture of 4-vinylpyridine, ethylacrylate, and p-DVB on polymerization using hydroxylapatite as suspension stabilizer and AIBN as the initiator gives an anion-exchange resin. 

A method for the introduction of thiol groups into proteins (and polyhydroxylic molecules such as dextran or polyvinyl alcohol) involves adding solid anhydride to a protein solution at pH 7 under nitrogen. Hydrolyzed anhydride is removed with an anion exchanger, salts with a mixed-bed exchanger or by dialysis, and the... 

Table 21-2 lists some liquid-membrane electrodes available from commercial sources. The anion-sensitive electrodes shown make use of a solution containing an anion-exchange resin in an organic solvent. Liquid-membrane electrodes in which the exchange liquid is held in a polyvinyl chloride gel have been developed for Ca-, K", NOj, and BF4. These have the appearance of crystalline electrodes, which are considered in the following section. A homemade liquid-membrane ion-selective electrode is described in Feature 21-1. 

Styrene/divinylbenzene copolymers, polymethacrylate, and polyvinyl resins are the most important organic compounds that were tested for their suitability as substrate materials in the manufacturing process for polymer-based anion exchangers. 

Polyvinyl-based anion exchange resins have been available since 1984 from Interaction Chemicals (Mountain View, CA, USA) under the trade names ION-100 and ION-110 , respectively [24], According to the manufacturer, these macroreticular resins are stable at pH values between 0 and 14, thus allowing the use of a great number of eluents. In comparison to TSK Gel IC-PW, this stationary phase exhibits a much lower chromatographic efficiency [25], As an example, the separation of simple inorganic anions on ION-110 with salicylate as the eluent is shown in Fig. 3-10. The characteristic structural and technical properties of theses columns are summarized in Table 3-3. 

Inhibition of animal cell cultures by ammonia has been overcome by either passing oxygen through a porous poly(tetrafluoroethylene) membrane into the culture or by continuous removal through a membrane of the same material (0.2-Jum pores) to aqueous phosphoric acid on the other side.245 Urea was removed by an anion-exchange membrane clamped over an insolubilized polyvinyl alcohol membrane containing urease.246 No ammonium ion returned back into the feed solution. A urease in poly(ethy-lene-co-vinyl acetate) converted urea on one side to ammonia for recovery on the other.247... 

Hu J, Zhang C, Cong J, Toyoda H, Nagatsu M, Meng Y (2011) Plasma-grafted alkaline anion-exchange membranes based on polyvinyl chloride for potential application in direct methanol fuel cells. J Power Sources 196 4483 1490... 

Like anion exchangers, cation exchangers are divided into polymer-based cation exchangers (PS-DVB, EVB-DVB, polymethacrylate, and polyvinyl copolymers), latex-agglomerated cation exchangers, silica-based, and other (e.g., crown ether, aluminia materials).Modern cation exchangers contain sulfonic, carboxylic, car-boxylic-phosphonic, and carboxylic-phosphonic-crown ether functional groups. 

Therefore, it never gained any significance in the market. With the introduction of Metrosep A Supp 4 and Supp 5 at the beginning of this decade, polyvinyl alcohol-based anion exchangers became more popular. While Metrosep A Supp... 

Relatively little work has been dcnie with anion exchange membranes prepared by casting a polymer already containing functional groups (approach c ). Also in this approach polystyrene and polyethylene polymers are usually used however other less common backbones such as polyvinyl acetate and chitosan have also been used to prepare anion exchange membranes [9-11]. 

Polyvinyl-based anion exchange resins have been available since 1984 from Interaction Chemicals (Mountain View, CA, USA) under the trade names lON-100 and ION-110 [30]. According to the manufacturer, these macroreticular resins are stable at pH values between 0 and 14, thus allowing the use of a... 

In [74], completely phosphoric acid-free inter-mediate-T membranes and MEAs from 1/1 (mole imidazole/mole PO3H2) blend membranes of the PBI B5 (Fig. 4.4) and the phosphonated polymer polyvinyl phosphonic acid (PVPA) S12 (Fig. 4.5) were presented and compared to PA-doped membranes and MEAs. In the MEAs, a Pt electrocatalyst was deposited onto multiwaUed carbon nanotubes (MWNT) which have previously been coated with B5. This technique has previously been used for the preparation of electrocatalysts for anion-exchange membrane fuel cells [75]. In the final step, the MWNTs were coated with a layer of S12. It turned out that these membranes and MEAs possessed much higher durabilities than membranes and MEAs which have been doped with PA, therefore opening leeway for long-lasting intermediate-T fuel cell membranes without the PA leaching problems which are always present in PA-doped intermediate-T membranes and MEAs [76]. 

The heat exchanger fins from aluminum or its alloy are coated with aqueous solution containing a water-soluble cellulose resin or polyvinyl alcohol and a surfactant to form a hydrophilic film. Phosphoric acid ester was used as anionic surfactant (0.05-4.5%) in aqueous solution to form a hydrophilic film showing contact angle with water of 5-32° [288]. 

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