Temperature effects on positronium formation and inhibition: a contribution to the elucidation of early spur processes. I. Glycerol/water mixtures

Jonah, Charles D.; Haessler, J.C. Abbé G. Duplâtre A.

doi:10.1016/0301-0104(81)80039-0

Cited by 22 publications

(3 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Also, Lobo et al 65 showed the decreasing of o ‐Ps intensity I 3 with increasing of the concentration of iodine on PVA. Moreover, the inhibition effect of I − was also confirmed by the reported data by Jonah et al 61 they found that there is an inhibition effect on the additive of I − and Cl − ions, in addition, the inhibition constant was found to increase with the increase of the temperature.…”

Section: Resultssupporting

confidence: 78%

“…Figure 3 displays the relative intensity I 3 / I 0 , (where I o is the o ‐Ps intensity of pure PVA sample) as a function of NaI concentration. The information in this figure demonstrates that NaI is having a repressing impact in the polymer as it does in watery arrangement 59‐62 . The data in Figure 3 is fitted with the empirical functions which are often used to describe the inhibition effect 55,56,62,63 :

I_{3} = I_{o} / [1 + {(α C)}^{β}],

where C is the additive concentration of NaI, I o is the o ‐Ps intensity at C = 0, and α and β are constants dependent on the solute and matrix.…”

Section: Resultsmentioning

confidence: 99%

“…49 The o-Ps hole volume size V o-Ps in nm 3 is calculable as; 1)The dependence of the Ps formation probability on the free volume (eg, the degree of crystallinity [50][51][52] ) as shown by Ps affinity in a modified Ore gap analysis 53 that NaI is having a repressing impact in the polymer as it does in watery arrangement. [59][60][61][62] The data in Figure 3 is fitted with the empirical functions which are often used to describe the inhibition effect 55,56,62,63 :…”

Section: Positron Annihilation Lifetimementioning

confidence: 99%

See 2 more Smart Citations

Study of the nanostructure of free volume and ionic conductivity of polyvinyl alcohol doped with NaI

Hmamm

Zedan

Hamed

et al. 2020

Polymers for Advanced Techs

View full text Add to dashboard Cite

Positron annihilation lifetime (PAL), AC conductivity, and impedance spectroscopy have been applied for the investigation of polyvinyl alcohol (PVA) doped with different concentrations of NaI in the range from zero to 25 wt%. Wide‐angle x‐ray diffraction measurements reveal that the addition of NaI to the PVA structure leads to a decrease in the crystallinity of the sample. The free volume size obtained from PAL measurements increases with the increase of the NaI concentration on PVA. NaI acts as an inhibitor of positronium formation on the doped polymer with inhibition constant of 0.028 (Mol%)−1. The ionic conductivity of the investigated sample was found to be correlated with the free volume size, which indicates the major role of free volume in the conduction mechanism. The AC conductivity of the prepared samples is measured at room temperature in the frequency range from 50 Hz to 5 MHz. The calculated values of frequency exponent s indicate the hopping mechanism in ionic conductivity. Impedance spectroscopy of PVA doped with different concentrations of NaI was studied. The appeared semi‐circle, in the Nyquist plot, denotes the bulk influence of PVA with different concentrations of NaI. This has been attributed to the parallel connection of bulk resistance and bulk capacitance. Also, the semi‐circle radius of Cole‐Cole plots was found to decrease with the increase of the concentration ratio (wt%) of NaI. So, the increase of the conductivity of PVA with the increase of NaI contents has been investigated.

show abstract

Section: Resultssupporting

confidence: 78%

I_{3} = I_{o} / [1 + {(α C)}^{β}],

where C is the additive concentration of NaI, I o is the o ‐Ps intensity at C = 0, and α and β are constants dependent on the solute and matrix.…”

Section: Resultsmentioning

confidence: 99%

Section: Positron Annihilation Lifetimementioning

confidence: 99%

See 1 more Smart Citation

Study of the nanostructure of free volume and ionic conductivity of polyvinyl alcohol doped with NaI

Hmamm

Zedan

Hamed

et al. 2020

Polymers for Advanced Techs

View full text Add to dashboard Cite

show abstract

On the Mechanism of Formation of Formation of Positronium in Polar Solvents

Alfassi

1984

Ber Bunsenges Phys Chem

View full text Add to dashboard Cite

In this paper it is shown that various results on the effect of solutes and temperature on the formation of positronium in polar solvents can be better explained by a hybrid model between the “Ore‐gap” model and the “spur” model, stating that both contribute to the formation of positronium but the inhibition in case of partial inhibitors as well as the enhancement is due only to the second model. Complete inhibition is explained as due to the removal of positronium by its oxidation rather than preventing its formation.

show abstract

Temperature Effect on the Positronium Formation in Organic Solutions

Alfassi

Ache

1985

Ber Bunsenges Phys Chem

View full text Add to dashboard Cite

Studies of the temperature dependence of the rate constants for inhibition of o‐Ps formation in organic solvents show either zero or negative activation energies. This is additional evidence for the hypothesis that the experimentally observed inhibition rate constant k is the ratio of rate constants of two competing reactions, one being the reaction of the precursor of the thermalized o‐Ps with the solute (rate constant k), followed by annihilation and the second being the thermalization of this precursor (rate constant k2).

show abstract

Temperature effects on positronium formation and inhibition: a contribution to the elucidation of early spur processes. I. Glycerol/water mixtures

Cited by 22 publications

References 38 publications

Study of the nanostructure of free volume and ionic conductivity of polyvinyl alcohol doped with NaI

Study of the nanostructure of free volume and ionic conductivity of polyvinyl alcohol doped with NaI

On the Mechanism of Formation of Formation of Positronium in Polar Solvents

Temperature Effect on the Positronium Formation in Organic Solutions

Contact Info

Product

Resources

About