Influence of the coagulation‐bath temperature on the phase‐separation process of poly(vinylidene fluoride)‐<i>graft</i>‐poly(<i>N</i>‐isopropylacrylamide) solutions and membrane structures

Guo, Yanglong; Feng, Xia; Chen, Li; Zhao, Yiping; Bai, Jin

doi:10.1002/app.31457

Cited by 24 publications

(21 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The solution of PVDF was cast and strickled onto a glass plate, and then immersed into pure water bath at 25°, after the coat on the glass plate had been subjected to a short time of evaporation in the air. The membranes were thoroughly rinsed with distilled water to remove the residual solvent and freeze‐dried in a lyophilizer (CHRIST company, ALPHA 1‐2) for 6 h at 60 degrees below zero [].…”

Section: Methodsmentioning

confidence: 99%

“…Therefore, the surface properties modification of PVDF membrane is of crucial importance to its widespread applications. The incorporation of desirable functionalities onto PVDF surfaces can be accomplished via several modification methods, such as ozonization, plasma treatment, electron beam (EB) exposure, click reaction [], and surface‐initiated controlled radical polymerizations [].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Study on the influence of reaction time on the structure and properties of the PVDF membrane modified through the method of atom transfer radical polymerization

Zhao

Zhou

et al. 2013

Polym Eng Sci

Self Cite

View full text Add to dashboard Cite

A thermo‐responsive membrane, poly(vinylidene fluoride) (PVDF‐g‐PNIPAAm), was successfully prepared from PVDF membrane through surface‐initiated atom transfer radical polymerization (ATRP) of a thermo‐responsive monomer, N‐isopropyl acrylamide (NIPAAm). The influence of the reaction time on ATRP was studied in detail. The grafting membrane was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and X‐ray photoelectron spectroscopy (XPS). The results showed that NIPAAm was successfully grafted on the PVDF membrane, the membrane pores became smaller and the reaction time of 36 h was in favor of surface‐initiated ATRP. The thermal stability of PVDF membrane and PVDF‐g‐PNIPAAm membranes was characterized by differential scanning calorimetry (DSC). Contact angles of membrane surface, water penetration and protein solution permeation were tested. Water contact angles of PVDF membrane reduced after the surface grafting of NIPAAm, which illuminated that the hydrophilicity of the grafted membrane was improved. The PVDF‐g‐PNIPAAm membranes exhibited good thermo‐responsive permeability and antifouling property. POLYM. ENG. SCI., 54:1013–1018, 2014. © 2013 Society of Plastics Engineers

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Study on the influence of reaction time on the structure and properties of the PVDF membrane modified through the method of atom transfer radical polymerization

Zhao

Zhou

et al. 2013

Polym Eng Sci

Self Cite

View full text Add to dashboard Cite

show abstract

“…All the structures indicate that phase separation is induced by nonsolvent penetration from both inner and outer surfaces of hollow fiber membranes and can be attributed to mechanisms of the coagulation process [26]. Our previous works [14,15] have found that phase separation process of PVDF-gPNIPAAm solution is mainly dependent on the crystallization of PVDF-g-PNIPAAm copolymer and transition between hydrophilicity and hydrophobicity of side chains. When the water of 258C (below the LCST of PNIPAAm) was used as the coagulant, the phase-separation process is dominated by instantaneous liquid-liquid demixing.…”

Section: Cross-sections Of Hollow Fiber Membranesmentioning

confidence: 91%

“…In this work, ethanol was used as the wetting agent and thus the contact angle y in the Washburn equation is zero following the ASTM standard F316-03. The porosity (e) of fiber membrane was determined according to our previous description [14] and calculated by Eq. 2:…”

Section: Pore Size and Porosity Of Hollow Fiber Membranementioning

confidence: 99%

Temperature‐sensitive PVDF hollow fiber membrane fabricated at different air gap lengths

Shen

Zhao

Feng

et al. 2013

Polymer Engineering & Sci

Self Cite

View full text Add to dashboard Cite

This article describes preparation of temperature-sensitive poly(vinylidene fluoride) hollow fiber membranes using the dry-wet spinning technique and investigates effects of air gap length on the structures and performances. In spinning these hollow fibers, N,N-dimethyl formamide and poly(ethylene glycol) (10,000) were used as the solvent and pore-forming agent, respectively. The prepared fiber membranes were characterized by scanning electron microscopy, pore size measurement, filtration experiments of pure water flux, and solutes with different molecular weights. The fiber membranes exhibit a quite asymmetric structures consisting of double skin layers situated on the fiber walls, two finger-like layers near skin layers as well as macrovoids and sponge-like structures at the center of the fiber cross-sections. Remarkable changes of pure water flux and retention of solute are observed around 328C, indicating an excellent temperature-sensitive permeability. As the air gap length increases, the pore size of fiber membrane decreases, which results in decrease of pure water flux and allows small molecules to permeate through the fiber membrane.

show abstract

“…The poly(vinylidenefluoride)‐graft‐poly(N‐isopropylacrylamide) (PVDF‐ g ‐PNIPAAm) membranes prepared by Guo et al at different temperatures formed finger‐like pores and showed higher water flux and porosity than PVDF membranes. In particular, a membrane prepared at 30°C had the largest finger‐like pores and greatest porosity.…”

Section: Introductionmentioning

confidence: 99%

Effect of the preparation conditions on the morphology and performance of poly(imide) hollow fiber membranes

Alsalhy

Salih

Melkon³

et al. 2014

J of Applied Polymer Sci

View full text Add to dashboard Cite

Poly(imide) (PI) hollow fiber membranes were prepared by using classical phase inversion process. Effects of different external coagulation bath temperatures (ECBT) and various bore flow rates (BFR) on the morphology and separation performance of the membranes were studied. Cross‐section, inner and outer structures were characterized by using scanning electron microscope and atomic force microscopy (AFM). Mean pore size, pore size distribution, and mean roughness of the PI hollow fibers surfaces were estimated by AFM. It was found that the hollow fibers morphology composed of sponge‐like and finger‐like structures with different ECBT and BFR. A circular shape of the nodules with different sizes was observed in the outer surface of the PI hollow fibers. Mean pore size of the outer surface increases with increasing ECBT and BFR. The important result observed in this study is that the ECBT clearly has the largest effect on hollow fiber PI membrane roughness compared with the BFR. Pure water permeability of the PI hollow fibers was improved with increase of ECBT and BFR. The solute rejection (R%) was reduced when the ECBT and BFR was increased. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40428.

show abstract

Influence of the coagulation‐bath temperature on the phase‐separation process of poly(vinylidene fluoride)‐graft‐poly(N‐isopropylacrylamide) solutions and membrane structures

Cited by 24 publications

References 12 publications

Study on the influence of reaction time on the structure and properties of the PVDF membrane modified through the method of atom transfer radical polymerization

Study on the influence of reaction time on the structure and properties of the PVDF membrane modified through the method of atom transfer radical polymerization

Temperature‐sensitive PVDF hollow fiber membrane fabricated at different air gap lengths

Effect of the preparation conditions on the morphology and performance of poly(imide) hollow fiber membranes

Contact Info

Product

Resources

About