Structural elucidation of morphology and performance of the PVDF/PEG membrane

Fadaei, Amir; Salimi, Ali; Mirzataheri, Mojgan

doi:10.1007/s10965-014-0545-x

Cited by 39 publications

(17 citation statements)

References 36 publications

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“…Owing to high volatility of acetone, the cloud points could not be determined for this system. The modeled phase curves for PVDF–NMP/DMF/DMAc–Water system are also in close agreement with the experimental cloud point data available in literature .…”

Section: Resultssupporting

confidence: 86%

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Role of thermodynamic and kinetic interaction of poly(vinylidene fluoride) with various solvents for tuning phase inversion membranes

Kurada

2017

Polymer Engineering & Sci

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An extensive study of thermodynamics and kinetics of non‐solvent induced phase separation was carried out for poly(vinylidene fluoride)/solvent/water system for four different solvents. Literature available on semicrystalline polymers was mostly based on experimental cloud points, obtained to a narrow range of polymer concentration (<10 wt%), much less than the working range for membrane preparation (20–25 wt%). Aim of this work was to model the thermodynamic phase diagram using extended Flory–Huggins theory which was used as a tool, along with the kinetic data to obtain tailor‐made membranes with desired morphology and properties. Interaction parameters involving solvent, nonsolvent, and polymer played an important role to tune the porosity of the membrane. Thermodynamic calculation showed solvent N,N‐dimethyl acetamide resulted in the most porous membrane (permeability 5.4 × 10−11 m Pa−1 s−1) followed by N,N‐dimethyl formamide (permeability 4.2 × 10−11 m Pa−1 s−1), N‐methyl pyrrolidone (permeability 3.8 × 10−11 m Pa−1 s−1), and acetone (impermeable to water even at 1380 kPa), which was the densest one. Prepared membranes were characterized in terms of surface morphology, molecular weight cut‐off, tensile strength, pore volume distribution, crystallinity, and surface roughness, which were correlated to inferences based on thermodynamic and kinetic calculations. POLYM. ENG. SCI., 58:1062–1073, 2018. © 2017 Society of Plastics Engineers

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Section: Resultssupporting

confidence: 86%

“…Moreover, the study was done for a single‐solvent system. Thermodynamics of PVDF with various solvent systems was studied experimentally in fair details using cloud point data by Bottino et al and Fadaei et al , but no theoretical understanding was developed.…”

Section: Introductionmentioning

confidence: 99%

Role of thermodynamic and kinetic interaction of poly(vinylidene fluoride) with various solvents for tuning phase inversion membranes

Kurada

2017

Polymer Engineering & Sci

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“…In other words, only a small amount of nonsolvent was needed to disturb the equilibrium of the solution system and induce the precipitation of the polymer when the temperature of coagulation bath was low. These results suggested that thermodynamic stability increased with increase in temperature . The thermodynamic stability of the PSf/DMAc/HCl systems was in the following sequence: 20 °C < 30 °C < 40 °C < 50 °C.…”

Section: Resultsmentioning

confidence: 84%

Preparation of Hollow Fiber Membranes by Nonsolvent Induced Phase Separation along with Hydrogen Gas Formation Using a Single Orifice Spinneret

Ying-bo

Hu³

et al. 2017

Macro Materials & Eng

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air gap distance, [7][8][9] flow rates of polymer solution, [10][11][12] and bore fluid, [13][14][15] phase behavior of polymer/solvent/nonsolvent ternary system, and rheology of polymer solution. [16,17] Composition, temperature, and pH of coagulation bath are also impor tant parameters that influence the mor phologies and properties of HFMs. [18][19][20] HFMs were fabricated by phase inver sion process of polymer solutions in late 1950s, which were mainly intended for a wide variety of purification and separation processes. [21] So far, many different types of HFMs have been manufactured by this method. [22,23] HFMs are mainly fabricated by nonsolvent induced phase separa tion (NIPS) and thermally induced phase separation techniques, which are effective strategies to produce HFMs with desirable structures and properties, in both labora tory and industrial scales. In a typical solution spinning and phase inversion process, an HFM is fabricated by extruding a concentrated polymeric solution through an annular gap of a concentric orifice spin neret into the external coagulation bath. [21] NIPS process is based on the exchange of solvent present inside the polymer solution with the nonsolvent in the coagulation bath to induce a phase separation of polymer solution from a liquid disper sion to a solid state. [24,25] In the wet spinning method, the dia meter and wall thickness of the HFMs mainly depends upon the inner/outer diameter of the spinneret and the properties of poly mer solution, since the stretching of the fibers is quite limited in this process. Efforts were made to overcome the for mation of irregular surface at high speed spinning rate. [26] In fact, the fabrication process of HFMs faces significant challenges. On the one hand, there is a need to redesign and fabricate fine spinnerets and replace them to regulate hollow fiber membranes. On the other hand, high quality pumps are required to obtain continuous and stable flow in order to ensure the stability of the hollow fiber membranes. These dif ferent factors limit the applicability of traditional techniques to produce HFMs.Lately, a new strategy was developed to solve these problems. HFMs were fabricated by a modified NIPS process, by using a spinneret with ingle orifice. Yao et al. [27] added organic oil to the polymer dope solution as a boreforming agent. The oil was pushed by the external coagulant (water) to the center of the fiber, and thus the HFMs could be obtained by washing away Hollow Fiber MembranesTraditional nonsolvent induced phase separation (NIPS) process for fabrication of hollow fiber membranes (HFMs) faces challenges, like design and manufacture of spinneret with two concentric orifices to provide parallel and continuous feed of polymer solution and bore fluid at specific rates. These factors limit the use of traditional technique to produce HFMs. Here, a new direct spinning method for fabricating HFMs by feeding a polymer solution, containing a gas producing agent using single orifice spinneret is reported. Polysulfone-dimethylacet...

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“…Although the experimental points of the four systems studied appeared very proximate at 293 K the position of the cloud points were significantly different between solvents (i.e., PVDF/DMAc/water vs. PVDF/NMP/water and PES/DMAc/water vs. PES/NMP/water) and between polymers (i.e., PVDF/DMAc/water vs. PES/DMAc/water and PVDF/NMP/water vs. PES/NMP/water). Cloud point experimental data obtained between 293 and 295 K (room temperature) are widely reported in the literature for the four systems studied [ 7 , 14 , 28 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ]. Experimental results of this study fall within the range of results previously reported at room temperature.…”

Section: Resultsmentioning

confidence: 99%

Thermodynamic Modeling and Validation of the Temperature Influence in Ternary Phase Polymer Systems

2021

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The effect of the temperature, as a process variable in the fabrication of polymeric membranes by the non-solvent induced phase separation (NIPS) technique, has been scarcely studied. In the present work, we studied the influence of temperature, working at 293, 313 and 333 K, on the experimental binodal curves of four ternary systems composed of PVDF and PES as the polymers, DMAc and NMP as the solvents and water as the non-solvent. The increase of the temperature caused an increase on the solubility gap of the ternary system, as expected. The shift of the binodal curve with the temperature was more evident in PVDF systems than in PES systems indicating the influence of the rubbery or glassy state of the polymer on the thermodynamics of phase separation. As a novelty, the present work has introduced the temperature influence on the Flory–Huggins model to fit the experimental cloud points. Binary interaction parameters were calculated as a function of the temperature: (i) non-solvent/solvent (g12) expressions with UNIFAC-Dortmund methodology and (ii) non-solvent/polymer (χ13) and solvent/polymer (χ23) using Hansen solubility parameters. Additionally, the effect of the ternary interaction term was not negligible in the model. Estimated ternary interaction parameters (χ123) presented a linear relation with temperature and negative values, indicating that the solubility of the polymers in mixtures of solvent/non-solvent was higher than expected for single binary interaction. Finally, PES ternary systems exhibited higher influence of the ternary interaction parameter than PVDF systems.

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Structural elucidation of morphology and performance of the PVDF/PEG membrane

Cited by 39 publications

References 36 publications

Role of thermodynamic and kinetic interaction of poly(vinylidene fluoride) with various solvents for tuning phase inversion membranes

Role of thermodynamic and kinetic interaction of poly(vinylidene fluoride) with various solvents for tuning phase inversion membranes

Preparation of Hollow Fiber Membranes by Nonsolvent Induced Phase Separation along with Hydrogen Gas Formation Using a Single Orifice Spinneret

Thermodynamic Modeling and Validation of the Temperature Influence in Ternary Phase Polymer Systems

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