Phase equilibrium and diffusion of solvents in polybutadiene: A capillary‐column inverse gas chromatography study

Cai, Wangfeng; Ramesh, Narayan; Tıhmınlıoğlu, Funda; Danner, Ronald P.; Haan, A.B. de

doi:10.1002/polb.10156

Cited by 10 publications

(12 citation statements)

References 24 publications

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“…The overall activation energy for diffusion can be obtained from an Arrhenius equation correlation of the diffusivity as a function of temperature and can be calculated from free-volume parameters. 24 Techniques have been developed so that all the parameters, (K 11 /c 1 ,K 12 /c 2 ,K 21 À T g1 and K 22 À T g2 ) can be estimated from properties of the two pure components comprising the mixture. 5,6,[25][26][27][28] The free-volume parameters are defined in terms of the thermal expansion coefficients of the two components.…”

Section: Free-volume Theorymentioning

confidence: 99%

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Application of free‐volume theory to self diffusion of solvents in polymers below the glass transition temperature: A review

Ramesh

Davis

Zielinski

et al. 2011

J Polym Sci B Polym Phys

Self Cite

104

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Theories based on free-volume concepts have been developed to characterize the self and mutual-diffusion coefficients of low molecular weight penetrants in rubbery and glassy polymer-solvent systems. These theories are applicable over wide ranges of temperature and concentration. The capability of free-volume theory to describe solvent diffusion in glassy polymers is reviewed in this article. Two alternative free-volume based approaches used to evaluate solvent self-diffusion coefficients in glassy polymer-solvent systems are compared in terms of their differences and applicability. The models can correlate/predict temperature and concentration dependencies of the solvent diffusion coefficient. With the appropriate accompanying thermodynamic factors they can be used to model concentration profiles in mutual diffusion processes that are Fickian such as drying of coatings. The free-volume methodology has been found to be consistent with molecular dynamics simulations. INTRODUCTIONThe diffusion of small molecules in polymers is of considerable practical importance and has been studied extensively. Diffusion theories based on the free-volume concept have been used extensively to correlate and predict solvent self-diffusion coefficients in rubbery polymersolvent systems.1-6 These methods provide accurate predictions over a wide range of temperatures and concentrations above the glass transition temperature of the pure polymer. As polymer solutions are cooled over practical time scales, the rate of cooling exceeds the rate of relaxation of the polymer, and a nonequilibrium state referred to as the glassy state results. This phenomenon causes volume to be trapped in the polymer in excess of that expected at equilibrium. Free-volume theory presumes that this extra volume is available to facilitate mass transport in the glassy state. Based on this concept, the original free-volume theory was adapted to describe the diffusion of a trace amount of a solvent in a glassy polymer, 7,8 and it was further extended to describe self-diffusion below the mixture glass transition temperature at finite concentrations of the solvent.

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Section: Free-volume Theorymentioning

confidence: 99%

“…For these predictions, the polymer free-volume parameters were the same as those given for polystyrene in Table 4. The D 0 and n were estimated using a linear correlation with the penetrant size following the approach described in a previous study by Cai et al 24 …”

Section: Reviewmentioning

confidence: 99%

Application of free‐volume theory to self diffusion of solvents in polymers below the glass transition temperature: A review

Ramesh

Davis

Zielinski

et al. 2011

J Polym Sci B Polym Phys

Self Cite

104

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show abstract

“…Strictly speaking, E act might change at T g of the matrix and is also a function of temperature above T g , thus complicating the interpretation of this value as an Arrhenius activation energy (Kumins and Roteman, 1961;Launay et al, 1999;Cai et al, 2002). Since our measurements are either mostly below or mostly above the T g of the respective matrix, we relate ζ o A to T g according to…”

Section: A2 Parameterization Of D W (T a W )mentioning

confidence: 99%

Viscous organic aerosol particles in the upper troposphere: diffusivity-controlled water uptake and ice nucleation?

Lienhard

Huisman

Krieger³

et al. 2015

Atmos. Chem. Phys.

118

190

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Abstract. New measurements of water diffusion in secondary organic aerosol (SOA) material produced by oxidation of α-pinene and in a number of organic/inorganic model mixtures (3-methylbutane-1,2,3-tricarboxylic acid (3-MBTCA), levoglucosan, levoglucosan/NH 4 HSO 4 , raffinose) are presented. These indicate that water diffusion coefficients are determined by several properties of the aerosol substance and cannot be inferred from the glass transition temperature or bouncing properties. Our results suggest that water diffusion in SOA particles is faster than often assumed and imposes no significant kinetic limitation on water uptake and release at temperatures above 220 K. The fast diffusion of water suggests that heterogeneous ice nucleation on a glassy core is very unlikely in these systems. At temperatures below 220 K, model simulations of SOA particles suggest that heterogeneous ice nucleation may occur in the immersion mode on glassy cores which remain embedded in a liquid shell when experiencing fast updraft velocities. The particles absorb significant quantities of water during these updrafts which plasticize their outer layers such that these layers equilibrate readily with the gas phase humidity before the homogeneous ice nucleation threshold is reached. Glass formation is thus unlikely to restrict homogeneous ice nucleation. Only under most extreme conditions near the very high tropical tropopause may the homogeneous ice nucleation rate coefficient be reduced as a consequence of slow condensed-phase water diffusion. Since the differences between the behavior limited or non limited by diffusion are small even at the very high tropical tropopause, condensed-phase water diffusivity is unlikely to have significant consequences on the direct climatic effects of SOA particles under tropospheric conditions.

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“…For the limited temperature range investigated in this work E act is assumed to be independent of temperature. Strictly speaking, E act might change at T g of the matrix and is also a function of temperature above T g , thus complicating the interpretation of this value as an Arrhenius activation energy (Kumins and Roteman, 1961;Launay et al, 1999;Cai et al, 2002). Since our measurements are either mostly below or mostly above the T g of the respective matrix, we relate ζ o A to T g according to…”

Section: Discussionmentioning

confidence: 99%

Viscous organic aerosol particles in the upper troposphere: diffusivity-controlled water uptake and ice nucleation?

Lienhard¹,

Huisman²,

Krieger³

et al. 2015

Preprint

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Abstract. New measurements of water diffusion in aerosol particles produced from secondary organic aerosol (SOA) material and from a number of organic/inorganic model mixtures (3-methylbutane-1,2,3-tricarboxylic acid (3-MBTCA), levoglucosan, levoglucosan/NH4HSO4, raffinose) indicate that water diffusion coefficients are determined by several properties of the aerosol substance and cannot be inferred from the glass transition temperature or bouncing properties. Our results suggest that water diffusion in SOA particles is faster than often assumed and imposes no significant kinetic limitation on water uptake and release at temperatures above 220 K. The fast diffusion of water suggests that heterogeneous ice nucleation on a glassy core is very unlikely in these systems. At temperatures below 220 K, model simulations of SOA droplets suggest that heterogeneous ice nucleation may occur in the immersion mode on glassy cores which remain embedded in a liquid shell when experiencing fast updraft velocities. The particles absorb significant quantities of water during these updrafts which plasticize their outer layers such that these layers equilibrate readily with the gas phase humidity before the homogeneous ice nucleation threshold is reached. Glass formation is thus unlikely to restrict homogeneous ice nucleation. Only under most extreme conditions near the very high tropical tropopause may the homogeneous ice nucleation rate coefficient be reduced as a consequence of slow condensed-phase water diffusion. Since the differences between the behavior limited or non limited by diffusion are small even at the very high tropical tropopause, condensed-phase water diffusivity is unlikely to have significant consequences on the direct climatic effects of SOA particles under tropospheric conditions.

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Phase equilibrium and diffusion of solvents in polybutadiene: A capillary‐column inverse gas chromatography study

Cited by 10 publications

References 24 publications

Application of free‐volume theory to self diffusion of solvents in polymers below the glass transition temperature: A review

Application of free‐volume theory to self diffusion of solvents in polymers below the glass transition temperature: A review

Viscous organic aerosol particles in the upper troposphere: diffusivity-controlled water uptake and ice nucleation?

Viscous organic aerosol particles in the upper troposphere: diffusivity-controlled water uptake and ice nucleation?

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