THE EXCHANGE OF Li+, Na+ AND K+ WITH H+ ON ZIRCONIUM PHOSPHATE1

Larsen, Edwin M.; Vissers, D.R.

doi:10.1021/j100840a031

Cited by 55 publications

(16 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ASh is equal to the difference in the hydration entropies of the two ions (Ht and Nat) and is obtained from the data of Rosseinsky (23 Table 1 shows that in all media, Ht/Nai exchange is an entropy-directed reaction. In the aqueous medium, this is in qualitative agreement with previous studies (24,25). In this medium, E' is negative, showing a decrease of entropy when H t in ZrP is replaced by Na '.…”

Section: I'supporting

confidence: 93%

Thermodynamics of H⁺/Na⁺ exchange on amorphous zirconium phosphate in mixed solvents

Misak¹,

Mikhail²

1983

Can. J. Chem.

View full text Add to dashboard Cite

AG" of the H'/Na' exchange on zirconium phosphate is positivc and changcs a littlc on addition of up to 90% mcthanol. On addition of isopropanol and acetonc, AG" bccomes lcss positivc. Both AH" and AS" becomc progrcssivcly lcss negative on adding increasing amounts of the organic solvcnts. The dccrcasc of AG" on addition of isopropanol and acetone is at least partly due to cffccts on thc ion-solvent interactions in thc liquid phasc. In thc casc of methanol, thesc effects lcad to a decrease of AG" but the decreasc is mostly balanccd by an increase due to effects on thc intcractions in solid phase. Thc lattcr effects involve an increase of enthalpy and a decrease of entropy, thcsc changcs are largcr thc highcr thc methanol content. Possiblc reasons for these enthalpy and entropy changes arc discussed.N. Z. MISAK ct E. M. MIKHAIL. Can. J. Chem. 61, 1902 (1983).LC AG" d'Cchange dc H'/Na' sur Ic phosphate dc zirconium est positif ct varic 1Cgkremcnt lorsqu'on ajoute du mCthanol a unc conccntration allant jusqu'i 90%. L'addition d'isopropanol ct d'acCtonc rend Ic AG" moins positif. Lcs AH" ct le AS" dcviennent progressivemcnt moins nCgatifs lorsqu'on ajoutc des quantitCs croissantcs de solvants organiqucs. La diminution de AG" lors de I'addition d'isopropanol ct d'acktonc cst due partiellcmcnt aux cffets des interactions ion-solvant dans la phase liquidc. Dans le cas du mCthanol, ccs cffcts provoqucnt unc diminution de AG", mais la diminution est contrc-balancCe par une augmentation due aux cffcts des interactions dans la phasc solidc. Lcs dernicrs effets impliquent une augmentation d'enthalpic ct une diminution d'cntropic qui sont plus fortcs lorsque la tencur cn mCthanol cst trks ClevCe. On discutc dcs causes possibles de ccs variations d'enthalpic et d'entropie.[Traduit par Ic journal] Introduction In a previous paper ( l ) , we reported on tracer equilibria, capacity and kinetics of exchange on amorphous zirconium phosphate (ZrP) in mixed solvents. It was established that in mixed solvents of up to 90% methanol and acetone and 60% isopropanol, Na' is sorbed by ZrP by an ion cxchange mechanism. With the exception of 90% methanol, the Na-capacity increases with the increase of the concentration of added organic solvent. The diffusion of Na' in ZrP is slackened in the presence of methanol and acetone. These results were tentatively discussed in terms of the possible effects of organic solvents on the hydration and solvation of Na', the basicity of the organic solvents, and the decrease of the dielectric constant inside the exchanger. "

show abstract

Section: I'supporting

confidence: 93%

Thermodynamics of H⁺/Na⁺ exchange on amorphous zirconium phosphate in mixed solvents

Misak¹,

Mikhail²

1983

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

“…The two groups must therefore have been exposed to roughly the same physical environment. As for stresses on the masticatory apparatus, there may have been some differences: the Norsemen probably had a slightly softer diet than the Eskimos (Bendixen, n.d.;Larsen, 1960;Nelson, 1969;Jenness, 1970;Persson, 19701, and may therefore have had slightly less masticatory stress. However, if masticatory stress alone should cause the appearance and development of the torus, it is the Eskimos who ought to have the larger, stronger torus, not the Norsemen.…”

Section: Discussionmentioning

confidence: 99%

Mandibular torus morphology

Sellevold

1980

American J Phys Anthropol

View full text Add to dashboard Cite

The morphology of the mandibular torus was examined, and comparisons were made between a Medieval Norse skeletal population from Greenland and a 14th to 17th century Greenland Eskimo skeletal series. Three parameters were analyzed: degree of development (on a 4-point scale), position and length, and surface morphology according to the number of knobs, or lobuli. It was found that the Eskimos have a high frequency of weakly developed tori and no cases of the extreme development, while over 20% of the Norsemen had tori in the "extreme" category. The Norse torus was generally found to be longer than that of the Eskimos, and both groups exhibited a slight asymmetry between the sides, the torus on the left side tending to be longer and more forward in position than the right. A great difference was found in surface morphology. The Norse torus is in general very irregular, while the Eskimo torus is rather smooth. These differences are believed to be genetically determined.

show abstract

“…Zirconium phosphate was synthesized according to previously published procedures [23,26,31]. b-Nicotinamide adenine dinucleotide, reduced form (NADH) was purchased from Sigma (St. Louis, MO, USA) as disodium salt.…”

Section: Methodsmentioning

confidence: 99%

NADH Oxidation Using Carbonaceous Electrodes Modified with Dibenzo‐Dithia‐Diazapentacene

et al. 2003

View full text Add to dashboard Cite

The electrochemical and the electrocatalytic behavior for NADH oxidation of a newly synthesized phenothiazine derivative, 16H,18H-dibenzo[c,1]-7,9-dithia-16,18-diazapentacene (DDDP), adsorbed on solid spectrographic graphite and on graphite powder or on zirconium phosphate (ZP), both entrapped in carbon paste, were compared. Experiments using cyclic voltammetry and a rotating disk electrode, performed in different experimental conditions (various pH values and NADH concentrations), showed that i) in the pH range between 4 and 8, the E8× value for DDDP adsorbed on ZP becomes pH independent; ii) in contrast to other redox mediators, adsorption of DDDP on ZP induced a significant negative shift of the E8× value; iii) the reaction rate for electrocatalytic oxidation of NADH is markedly increased by adsorbing the mediator on ZP, being further improved by the presence of Ca 2 ions in the solution.

show abstract

THE EXCHANGE OF Li⁺, Na⁺ AND K⁺ WITH H⁺ ON ZIRCONIUM PHOSPHATE¹

Cited by 55 publications

References 0 publications

Thermodynamics of H⁺/Na⁺ exchange on amorphous zirconium phosphate in mixed solvents

Thermodynamics of H⁺/Na⁺ exchange on amorphous zirconium phosphate in mixed solvents

Mandibular torus morphology

NADH Oxidation Using Carbonaceous Electrodes Modified with Dibenzo‐Dithia‐Diazapentacene

Contact Info

Product

Resources

About

THE EXCHANGE OF Li+, Na+ AND K+ WITH H+ ON ZIRCONIUM PHOSPHATE1

Cited by 55 publications

References 0 publications

Thermodynamics of H+/Na+ exchange on amorphous zirconium phosphate in mixed solvents

Thermodynamics of H+/Na+ exchange on amorphous zirconium phosphate in mixed solvents

Mandibular torus morphology

NADH Oxidation Using Carbonaceous Electrodes Modified with Dibenzo‐Dithia‐Diazapentacene

Contact Info

Product

Resources

About

THE EXCHANGE OF Li⁺, Na⁺ AND K⁺ WITH H⁺ ON ZIRCONIUM PHOSPHATE¹

Thermodynamics of H⁺/Na⁺ exchange on amorphous zirconium phosphate in mixed solvents

Thermodynamics of H⁺/Na⁺ exchange on amorphous zirconium phosphate in mixed solvents