Hydroxide-exchange

Bhaumik, A., Samanta, S. and Mai, N.K. (2005) Efficient removal of arsenic from polluted ground water by using a layered double hydroxide exchanger. Indian Journal of Chemistry, Section A Inorganic, Physical, Theoretical and. Analytical Chemistry, 44(7), 1406-9. 

How do the different buffer systems in the soil (Al-hydroxide-, exchanger- (50 % NaX, 30 % CaX2, 20 % MgX2), carbonate-, Fe-hydroxide-, Mn-hydroxide buffer) affect the chemical composition of the rainwater of the previous exercise (chapter 3.1.2.1) when it infiltrates in the soil (C02 partial pressure 1 Vol%) ... 

Equations 4.1-4.6 illustrate the fundamental conceptual steps involved in describing the dissociation characteristics of strong cation (sulfonic acid) and strong anion (quaternary ammonium hydroxide) exchangers, where the bar notation represents the resin phase. Once understood, dissociation in the resin phase is implied where appropriate, as illustrated by equations 4.7 and 4.8. 

On solving the above equations simultaneously, the flux for ammonium transference can be determined. A similar set of equations can be generated for phosphate-hydroxide exchange. Table 3 shows data of preliminary, unpublished study conducted by the lead author in this area. 

B. F. Sels, D. E. De Vos, M. Buntinx, F. Pierard, A. Kirsh-De Mesmacker, P. A. Jacobs, Layered double hydroxides exchanged with tungstate as biomimetic catalysts for mild oxidative bromination, Nature 400 (1999) 855. 

One rock-alkali interaction is described by the sodium/hydrogen-base exchange (hydroxide-exchange),... 

FIGURE 10.11 Hydroxide-exchange isotherms for Wilmington oil sand. Source Somerton and Radke (1983). 

The results obtained are depicted in Figure 2. The curve obtained for reversible adsorption is typical of adsorption isotherms and the results obtained are in general agreenent with the hydroxide exchange isotherms by Sonerton and Radke (11) using the same sand. They are of the order of 1 meq/lOOg sand. 

Yan X, He G, Gu S, Wu X, Du L, Wang Y (2012) Imidazolium-functionalized polysulfone hydroxide exchange membranes for potential applications in alkaline membrane direct alcohol fuel cells. Int J Hydrogen Energ 37 5216-5224... 

PAES has been functionalized with quaternary guanidinium groups for use in polymeric hydroxide exchange membranes. The quaternized polymers could be synthesized by the chloromethylation of PAES, followed by the reaction with pentamethyl-guanidine, c.f.. Figure 7.15 [113]. 

Hydroxide Exchange Membrane Alkali Fuel Cells (HEMFCs)... 

As previously pointed out by Lasaga and Gibbs (1990), there is reason to believe that the hydroxide exchange reaction between water and quartz proceeds by way of a fivefold coordinate silicon intermediate. The existence and nature of this five-fold coordinate silicon atom was further investigated by Kubicki et al. (1993). They determined the gas-phase reaction path of the addition of hydroxide to orthosilicic acid and a subsequent ab stracti on of H2O. 

Terrestrial applications may become possible when durable hydroxide exchange membranes are developed and used. 

Sleighthobne AES, Varcoe JR, Kucemak AR (2008) Oxygen reduction at the silver/hydroxide-exchange membrane interface. Electrochem Commun 10 151-155. doi 10.1016/j.elecom.2007.11.008... 

GuS, CaiR, LuoT, Chen Z, Sun M, Liu Y, He G, Yan Y (2009) A soluble and highly conductive ionomer for high-performance hydroxide exchange membrane fuel cells. Angew Chem 121 6621-6624. doi 10.1002/ange.200806299... 

C. Nyambo, P. Songtipya, E. Manias, M. M. Jimenez-Gasco, and C. A. Wilkie, Effect of MgAl-layered double hydroxide exchanged with linear alkyl carboxylates on fire-retardancy of PMMA and PS. Journal of Materials Chemistry, 18 (2008), 4827-38. 

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