A generalized solution—diffusion model of the pervaporation process through composite membranes Part I. Prediction of mixture solubilities in the dense active layer using the UNIQUAC model

Heintz, Andreas; Stephan, W.

doi:10.1016/0376-7388(93)e0222-6

Cited by 109 publications

(48 citation statements)

References 6 publications

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“…With increasing membrane thickness, the resistance across membrane increases, therefore the water flux decreases. According to the solution-diffusion model, at steady state, diffusion flow is constant and there is an inverse relationship between the flux and membrane thickness [13,23,25]. Figure 12 shows a linear relationship between the water flux and the reciprocal of the membrane thickness, as predicted by the Fick's law from the solution-diffusion model (Eqution 5).…”

Section: Pervaporation Testingmentioning

confidence: 97%

“…Therefore, the hydrophobicity increased. The solution-diffusion model is usually used to describe the transport mechanism of the pervaporation process which involves three steps: sorption at the membrane surface, diffusion through the dense membrane and desorption into the vacuum [23]. Under the high vacuum used in the study, the desorption step on the permeate side of the membrane is believed to be a fast step and diffusion is generally considered to be the controlling step [2].…”

Section: Swelling Studies and Contact Anglementioning

confidence: 99%

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Sol–gel derived poly(vinyl alcohol)/maleic acid/silica hybrid membrane for desalination by pervaporation

Xie

Hoang

Duong

et al. 2011

Journal of Membrane Science

134

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Highly dispersed homogeneous hybrid polymer-inorganic membranes based on poly(vinyl alcohol) (PVA), maleic acid (MA) and inorganic silica were synthesized via a sol-gel method. Tetraethoxy-silane (TEOS) was used as the silica precursor with MA as an additional crosslinking agent. A range of techniques such as FTIR, SEM, TGA, XRD and DSC were used to characterise the nanostructure and properties of hybrid membranes. Results revealed silica nanoparticles (<10 nm) were well dispersed in the polymer matrix with chemical bonding between the organic and inorganic phases. Thermal properties of the hybrid membranes were significantly enhanced when compared with pure PVA membranes, and swelling of PVA based hybrid membranes was greatly suppressed.The chemically crosslinked PVA with maleic acid and silica resulted in the formation of new hybrid membranes with improved pervaporation properties for desalination application. The pervaporation separation performance of aqueous salt solution was found to be directly related to the diffusion coefficient of water through hybrid PVA/MA/silica membranes. Introduction of MA and silica at given amounts into the polymer chain increased the amorphous region of the membrane and favoured the diffusion of water molecules through the membrane. A water flux of 6.93 kg/m 2 ·hr with salt rejection of >99.5% was achieved at a 6 Torr vacuum and 22°C.

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Section: Pervaporation Testingmentioning

confidence: 97%

Section: Swelling Studies and Contact Anglementioning

confidence: 99%

Sol–gel derived poly(vinyl alcohol)/maleic acid/silica hybrid membrane for desalination by pervaporation

Xie

Hoang

Duong

et al. 2011

Journal of Membrane Science

134

View full text Add to dashboard Cite

show abstract

“…Recent research indicates that association of polymer solutions has an obvious effect not only on solution phase equilibria, but also the extent of association changes with solvent concentration and temperature. 19,20 Heintz and Stephan 21,22 used the UNIQUAC model to predict organic aqueous solubility in a poly(vinyl alcohol) membrane, in which an empirical constant was introduced to account for the hydrogen-bonding effect, by adding a parameter to the canonical formalism. Although this model considered the effect of hydrogen bonding on solubility prediction, it still provided no clear physical picture of association.…”

Section: Introductionmentioning

confidence: 99%

Effect of molecular association on solubility, diffusion, and permeability in polymeric membranes

Wang

Yamaguchi

Nakao

2000

J. Polym. Sci. B Polym. Phys.

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“…Therefore, the salt rejection increased upon heating. membrane surface, diffusion through the dense membrane and desorption into the vacuum [24]. Under the high vacuum used in the study, the desorption step on the permeate side of the membrane is believed to be a fast step.…”

Section: Pervaporation Testingmentioning

confidence: 99%

Effect of heat treatment on pervaporation separation of aqueous salt solution using hybrid PVA/MA/TEOS membrane

Xie

Hoang

et al. 2014

Separation and Purification Technology

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Heat treatment is believed to be an important step in controlling the morphology and properties of polymer based membranes. In this study, hybrid organic-inorganic membrane based on poly(vinyl alcohol) (PVA), maleic acid (MA) and tetraethyl orthosilicate (TEOS) was synthesised via a sol-gel route. The effects of heating temperature and heating time on pervaporation separation performance of aqueous salt solution were studied in relation to swelling and hydrophilic properties, the free volume, salt transport properties, and water diffusivity of the membrane. The free volume of the hybrid membrane under different heat treatment conditions were well correlated with the pervaporation testing results. With increasing heating temperature or time, the fractional free volume of the hybrid membrane was reduced due to a more compact structure by crosslinking among PVA, MA and TEOS. As a result, the water flux decreased and the salt rejection increased. The salt transport properties followed a similar trend as the water uptake, indicating the hydrated NaCl was solvated by water in the membrane phase.

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A generalized solution—diffusion model of the pervaporation process through composite membranes Part I. Prediction of mixture solubilities in the dense active layer using the UNIQUAC model

Cited by 109 publications

References 6 publications

Sol–gel derived poly(vinyl alcohol)/maleic acid/silica hybrid membrane for desalination by pervaporation

Sol–gel derived poly(vinyl alcohol)/maleic acid/silica hybrid membrane for desalination by pervaporation

Effect of molecular association on solubility, diffusion, and permeability in polymeric membranes

Effect of heat treatment on pervaporation separation of aqueous salt solution using hybrid PVA/MA/TEOS membrane

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