Thermoosmosis of water, methanol, and ethanol through cellulose acetate membranes

Mengual, J.I.; García-López, F.

doi:10.1016/0021-9797(88)90034-3

Cited by 7 publications

(4 citation statements)

References 22 publications

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“…The thermo-osmotic coefficient was, in their model, a function of the temperature-dependent permeant adsorption enthalpy, molar volume, enthalpy of transfer and phenomenological coefficient, assuming that the membrane-permeant system was without single charges. Interesting is that an Arrhenius behaviour in D T has been observed with water and methanol in Nafion membranes [4] as well as in other membrane systems [30,34,39]. One possibility is to ascribe this to the hydraulic permeability.…”

Section: The Effect Of Average Temperaturementioning

confidence: 99%

“…The temperature dependence of the membrane absorption enthalpy and of the phenomenological coefficient were important factors. During the 1980s and 1990s, many studies were carried out on ion-exchange membranes and hydrophobic membranes with electrolyte solutions as permeants [36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51].…”

Section: The Field Becomes Establishedmentioning

confidence: 99%

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Thermo-osmosis in Membrane Systems: A Review

Barragán

Kjelstrup

2017

Journal of Non-Equilibrium Thermodynamics

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We give a first review of experimental results for a phenomenon little explored in the literature, namely thermal osmosis or thermo-osmosis. Such systems are now getting increased attention because of their ability to use waste heat for separation purposes. We show that this volume transport of a solution or a pure liquid caused by a temperature difference across a membrane can be understood as a property of the membrane system, i. e. the membrane with its adjacent solutions. We present experimental values found in the literature of thermo-osmotic coefficients of neutral and hydrophobic as well as charged and hydrophilic membranes, with water and other permeant fluids as well as electrolyte solutions. We propose that the coefficient can be qualitatively explained by a formula that contains the entropy of adsorption of permeant into the membrane, the hydraulic permeability, and a factor that depends on the interface resistance to heat transfer. A variation in the entropy of adsorption with hydrophobic/hydrophilic membranes and structure breaking/structure making cations could then explain the sign of the permeant flux. Systematic experiments in the field are lacking and we propose an experimental program to mend this situation.

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Section: The Effect Of Average Temperaturementioning

confidence: 99%

Section: The Field Becomes Establishedmentioning

confidence: 99%

Thermo-osmosis in Membrane Systems: A Review

Barragán

Kjelstrup

2017

Journal of Non-Equilibrium Thermodynamics

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“…A uniform membrane surface temperature in contact with hot and cold solutions is required to quantify the thermo-osmotic water flux. To reduce temperature difference between bulk solution and interface and enhance the uniformity, high flow rate circulation was used in the thermo-osmotic studies (14,15,(21)(22)(23)(24). The difference of mean temperature between hot and cold solutions, instead of the surface temperature, was used since measuring the surface temperature is challenging due to convective thermal boundary layer (16,22).…”

Section: Methods Of Approachmentioning

confidence: 99%

Temperature Gradient Induced Water Transport in Polymer Electrolyte Fuel Cells

Kim

Mench

2008

ECS Trans.

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The objective of this work is to investigate water transport of polymer electrolyte fuel cell (PEFC) materials subjected to a temperature gradient. Direct thermo-osmotic experiments on different polymer membrane types (non-reinforced Nafion ® , reinforced A, and reinforced B membrane) were performed using an in-house fuel cell fixture with a parallel flow field. Thermoosmotic flow was observed in all membranes, and the water flow direction (in the membrane only) was determined to always flow from the cold side to the hot side. The water flux was found to be proportional to temperature gradient and increased with average temperature. The dependency of the thermo-osmotic diffusivity on average temperature showed predictable Arrhenius-type behavior. For the membrane electrode assembly (MEA), net flow was determined to be from the hot to cold side due to a phase-change effect, which will be discussed in detail in a later publication. Interface temperatures of membrane were estimated using 2-dimensional thermal model, leading to empirical relations of thermo-osmotic diffusivity across the membrane.

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“…Membrane distillation (MD) is a thermal membrane separation process driven by the vapor pressure difference across a hydrophobic porous membrane. [1][2][3] The advantages of MD processes include low-temperature and low-pressure operating conditions, reduced interaction between the membrane and the feed solution, and a small space requirement for the vapor. 4 Primarily, there are four modes of MD configurations.…”

Section: Introductionmentioning

confidence: 99%

Preparation of a hydrophobically enhanced antifouling isotactic polypropylene/silicone dioxide flat‐sheet membrane via thermally induced phase separation for vacuum membrane distillation

Tang

Han

Yuan

et al. 2015

J of Applied Polymer Sci

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Isotactic polypropylene (iPP) hydrophobic flat-sheet membranes were fabricated for use in vacuum membrane distillation (VMD) through a thermally induced phase-separation process with dispersing hydrophobically modified SiO 2 nanoparticles in the casting solution to achieve a higher hydrophobicity and to sustain a stable flux in VMD. The contact angle (CA) measurements indicated that the incorporation of nano-SiO 2 into a casting solution mixture containing 20 wt % iPP had a 20.9% higher CA relative to that of SiO 2 -free membranes. The addition of nano-SiO 2 also induced morphological changes in the membrane structure, including changes in the pore size distribution, porosity, and suppression of macrovoids. The pore size distribution of the iPP-SiO 2 membranes became narrower compared with that of the SiO 2 -free membranes, and the porosity also improved from 35.45 to 59.75% with SiO 2 addition. The average pore size and maximum pore size of the iPP-SiO 2 membranes both decreased. The ability of the membranes to concentrate an astragalus aqueous solution (a type of traditional Chinese medicine) with VMD was investigated. The surface hydrophobicity and antifouling performance of the iPP-SiO 2 membranes improved with nano-SiO 2 addition to the membrane casting solution.

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Thermoosmosis of water, methanol, and ethanol through cellulose acetate membranes

Cited by 7 publications

References 22 publications

Thermo-osmosis in Membrane Systems: A Review

Thermo-osmosis in Membrane Systems: A Review

Temperature Gradient Induced Water Transport in Polymer Electrolyte Fuel Cells

Preparation of a hydrophobically enhanced antifouling isotactic polypropylene/silicone dioxide flat‐sheet membrane via thermally induced phase separation for vacuum membrane distillation

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