Effects of exposure time on variations in the structure and hydrophobicity of polyvinylidene fluoride membranes prepared via vapor-induced phase separation

Peng, Yongbo; Fan, Hongwei; Dong, Yajun; Song, Yanyan; Han, Hua

doi:10.1016/j.apsusc.2012.04.108

Cited by 88 publications

(47 citation statements)

References 36 publications

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“…Lower polymer concentrations are more likely to experience spinodal-decomposition (SD), producing a net-like surface structure in favor of the superhydrophobic property because their initial compositions are closer to the critical point in which binodal and spinodal lines are in a very close proximity [5]. Indeed, it was found that PVDF concentration affected membrane surface morphology, as shown in Figure 4.…”

Section: Effect Of Pvdf Concentrationmentioning

confidence: 87%

“…It was only observed in the 8% case as can be seen in the inset of the 8% membrane in Figure 4. This is mainly because of relatively high applied concentrations of PVDF compared to the one applied by [5]. Net-like structure is expected only during SD at very low PVDF concentrations and under high casting temperature (60 • C) and high RH (100%).…”

Section: Effect Of Pvdf Concentrationmentioning

confidence: 99%

“…The NIPS process is the most popular and has been used to prepare different types of membranes, including reverse osmosis, nanofiltration, ultrafiltration, microfiltration and MD [5,6]. When used to produce PVDF membranes in a strong solvent/non-solvent system, typically, the NIPS process is characterized by a relatively fast mass transfer rate (instantaneous demixing, relative to VIPS) leading to asymmetric structure (dense top layer, supported by a more porous layer) [5], narrow pore size distribution (PSD), relatively low mean flow pore size (MPS) and maximum pore size (BP) very close to MPS; all are desired properties of an MD membrane. However, under those same conditions, NIPS also produces a membrane with a fairly smooth surface (low roughness) leading to a low surface energy (high CA), which promotes low LEP and thus membrane wetting.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Improving Liquid Entry Pressure of Polyvinylidene Fluoride (PVDF) Membranes by Exploiting the Role of Fabrication Parameters in Vapor-Induced Phase Separation VIPS and Non-Solvent-Induced Phase Separation (NIPS) Processes

AlMarzooqi¹,

Bilad²,

Arafat³

2017

Applied Sciences

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Polyvinylidene fluoride (PVDF) is a popular polymer material for making membranes for several applications, including membrane distillation (MD), via the phase inversion process. Non-solvent-induced phase separation (NIPS) and vapor-induced phase separation (VIPS) are applied to achieve a porous PVDF membrane with low mass-transfer resistance and high contact angle (hydrophobicity). In this work, firstly, the impacts of several preparation parameters on membrane properties using VIPS and NIPS were studied. Then, the performance of the selected membrane was assessed in a lab-scale direct-contact MD (DCMD) unit. The parametric study shows that decreasing PVDF concentration while increasing both relative humidity (RH) and exposure time increased the contact angle and bubble-point pore size (BP). Those trends were investigated further by varying the casting thickness. At higher casting thicknesses and longer exposure time (up to 7.5 min), contact angle (CA) increased but BP significantly decreased. The latter showed a dominant trend leading to liquid entry pressure (LEP) increase with thickness.

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Section: Effect Of Pvdf Concentrationmentioning

confidence: 87%

Section: Effect Of Pvdf Concentrationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Improving Liquid Entry Pressure of Polyvinylidene Fluoride (PVDF) Membranes by Exploiting the Role of Fabrication Parameters in Vapor-Induced Phase Separation VIPS and Non-Solvent-Induced Phase Separation (NIPS) Processes

AlMarzooqi¹,

Bilad²,

Arafat³

2017

Applied Sciences

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“…Phase inversion takes place due to inflow of non-solvent vapors into polymeric casted film and outflow of solvent from casted film. Mass transfer of non-solvent vapors is dominated as compared to solvent due to its low volatility [77][78][79]. Peng et al [72] prepared PVDF membrane via VIPS method using various exposure times.…”

Section: Vapor Induced Phase Separation (Vips) and Evaporation Induced mentioning

confidence: 99%

A Comprehensive Review on Polymeric Nano-Composite Membranes for Water Treatment

Zahid¹,

Rashid²,

Akram³

et al. 2018

J Membr Sci Technol

188

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During last few decades, membrane technology has emerged as an efficient technique over conventional methods due to its high removal capacity, ease in operation and cost effectiveness for wastewater treatment and production of clean water. Membrane based separations are commonly based on polymeric membranes because of their higher flexibility, easily pore forming mechanism, low cost and smaller space for installation as compared to inorganic membranes. Commonly employed membrane fabrication phase inversion method has been shortly reviewed in this article. Major limitation of membrane based separations is fouling and polymeric membranes being hydrophobic in nature are more prone to fouling. Fouling is a deposition of various colloidal particles, macromolecules (polysaccharides, proteins), salts etc. on membrane surface and within pores thus impedes membrane performance, reduces flux and results in high cost. Modification of polymeric membranes due to its tailoring ability with nanomaterials such as metal based and carbon based results in polymeric nano-composite membranes with high antifouling characteristics. Nanomaterials impart high selectivity, permeability, hydrophilicity, thermal stability, mechanical strength, and antibacterial properties to polymeric membranes via blending, coating etc. modification methods. Characterization techniques has also discussed in later section for studying morphological properties and performance of polymer nano-composite membranes. Graphical Abstract

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“…Nowadays, very few researchers had focused on the removal of AA from an aqueous phase using the SLM process. 10 In SLM process, the polymeric membrane support plays an important role in the transport and performance of the process. For an efficient immersion of the organic liquid membrane phase inside the support, the microporous polymeric membrane with small pore size, high porosity, high tensile strength, high hydrophobicity and highly resistant to chemical should be used.…”

Section: Introductionmentioning

confidence: 99%

Effect of VIPS fabrication parameters on the removal of acetic acid by supported liquid membrane using a PES–graphene membrane support

et al. 2018

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In this study, the removal of acetic acid by supported liquid membrane (SLM) using hybrid polyethersulfone (PES)-graphene membrane prepared by vapor induced phase separation (VIPS) was investigated. The effects of graphene loading, coagulation bath temperature, air exposure time, and air humidity on the morphology, mechanical strength, porosity, and contact angle of the membrane were analyzed. The performance and stability of the hybrid membrane as a SLM support for acetic acid removal were studied. The best PES-graphene membrane support was produced at a coagulation bath temperature of 50 C, an air exposure time of 30 s and air humidity of 80%. The fabricated membrane has a symmetrical micropore cellular structure, high porosity and high contact angle. Under specific SLM conditions, almost 95% of acetic acid was successfully removed from 10 g L À1 aqueous acetic acid solution. The hybrid membrane remains stable for more than 116 h without suffering any membrane breakage during the continuous SLM process.

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Effects of exposure time on variations in the structure and hydrophobicity of polyvinylidene fluoride membranes prepared via vapor-induced phase separation

Cited by 88 publications

References 36 publications

Improving Liquid Entry Pressure of Polyvinylidene Fluoride (PVDF) Membranes by Exploiting the Role of Fabrication Parameters in Vapor-Induced Phase Separation VIPS and Non-Solvent-Induced Phase Separation (NIPS) Processes

Improving Liquid Entry Pressure of Polyvinylidene Fluoride (PVDF) Membranes by Exploiting the Role of Fabrication Parameters in Vapor-Induced Phase Separation VIPS and Non-Solvent-Induced Phase Separation (NIPS) Processes

A Comprehensive Review on Polymeric Nano-Composite Membranes for Water Treatment

Effect of VIPS fabrication parameters on the removal of acetic acid by supported liquid membrane using a PES–graphene membrane support

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