Preparation of hydrophilic modified polyvinylidene fluoride (PVDF) ultrafiltration membranes by polymer/non-solvent co-induced phase separation: effect of coagulation bath temperature

2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Xiaoming Zhang ◽  
Qingchen Lu ◽  
Nana Li
Keyword(s):  
Phase Separation ◽  
Membrane Fouling ◽  
Membrane Structure ◽  
Polyvinylidene Fluoride ◽  
Membrane Surface ◽  
Pure Water ◽  
Bath Temperature ◽  
Coagulation Bath ◽  
Separation Performance ◽  
Coagulation Bath Temperature

Abstract Membrane separation technology is widely used in wastewater purification, but the issue of membrane fouling could not be ignored. Hydrophilic modification is an effective method to reduce membrane fouling. Therefore, in this work, a hydrophilic modified polyvinylidene fluoride (PVDF) ultrafiltration membrane was prepared by polymer/non-solvent co-induced phase separation, and the effect of coagulation bath temperature on the membrane structure and performance was systematically investigated based on the previous study. With the increased of the coagulation bath temperature, the phase separation process changed from delayed to instantaneous, and the membrane surface changed from porous to dense, while the macropore structures and sponge-like pores appeared on the cross-section. Meanwhile, the pure water flux decreased from 229.3 L/(m2·h) to 2.08 L/(m2·h), the protein rejection rate increased from 83.87% to 100%, and the surface water contact angle increased from 63° to 90°. Thus, excessively high coagulation bath temperature adversely affected the permeate and separation performance, as well as antifouling performance of the membrane. This study enriched the research for preparing separation membranes by polymer/non-solvent co-induced phase separation and provided a practical and theoretical reference for controlling the membrane structure and properties by changing the coagulation bath temperature.

Effect of Additive on the Performance of PVDF Membrane via Non-Solvent Induced Phase Separation

2014 ◽  
Vol 789 ◽  
pp. 240-248 ◽  
Author(s):  
Xiao Hui Cao ◽  
Ming Qiu ◽  
Ai Wen Qin ◽  
Chun Ju He ◽  
Hai Feng Wang
Keyword(s):  
Tensile Strength ◽  
Phase Separation ◽  
Propylene Glycol ◽  
Pure Water ◽  
Polymer Concentration ◽  
Water Flux ◽  
Bath Temperature ◽  
Coagulation Bath ◽  
Breaking Elongation ◽  
Coagulation Bath Temperature

Poly (vinylidene fluoride) membranes were prepared from the ternary mixture of PVDF/ 1, 2 - propylene glycol/dimethylacetamidevianon-solvent induced phase separation (NIPS). The effect of the addition of the 1, 2 - propylene glycol content, the Coagulation Bath Temperature and the concentration of PVDF on the performance and structure of the PVDF membranes was studied in the present investigation.The results showed that with increasing polymer concentration, the mechanical strength increased,and the structure of membrane changed from finger-like macro-voids structureto sponge-like structure.It was found that water flux, breaking elongation and tensile strength of the membrane increased with increasing 1, 2 - propylene glycol content, when the content reached 41wt.%, the water flux reaches a maximum.The morphology of PVDF can be improved by the addition of 1, 2 - propylene glycol, which was changed from finger-like structure to sponge-like structure. And the dense skin layer of PVDF membranes became thicker with increasing 1, 2 – propyleneglycol. The tensile strength decreasedfrom 3.3 to 2.1MPa, breaking elongation decreased from 315% to 280% andthe pure water flux increased from 91 to 909 L·m-2·h-1. as the coagulation bath temperature (CBT) decreased from 30°C to 5°C.With this condition, the sponge-like hollow fiber membrane hassuccessfully spun.

scholarly journals Effect of Precipitation Temperature on the Properties of Cellulose Ultrafiltration Membranes Prepared via Immersion Precipitation with Ionic Liquid as Solvent

Membranes ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 87 ◽  
Author(s):  
Daria Nevstrueva ◽  
Arto Pihlajamäki ◽  
Juha Nikkola ◽  
Mika Mänttäri
Keyword(s):  
Ionic Liquid ◽  
Pure Water ◽  
Polymer Concentration ◽  
Water Flux ◽  
Bath Temperature ◽  
Liquid Solution ◽  
Coagulation Bath ◽  
Fouling Resistance ◽  
Ultrafiltration Membranes ◽  
Coagulation Bath Temperature

Supported cellulose ultrafiltration membranes are cast from a cellulose-ionic liquid solution by the immersion precipitation technique. The effects of coagulation bath temperature and polymer concentration in the casting solution on the membrane morphology, wettability, pure water flux, molecular weight cut-off, and fouling resistance are studied. Scanning electron microscopy, contact angle measurements, atomic force microscopy, and filtration experiments are carried out in order to characterise the obtained ultrafiltration cellulose membranes. The results show the effect of coagulation bath temperature and polymer concentration on the surface morphology and properties of cellulose ultrafiltration membranes. Optimisation of the two parameters leads to the creation of dense membranes with good pure water fluxes and proven fouling resistance towards humic acid water solutions.

scholarly journals Development of Polysulfone Membrane via Vapor-Induced Phase Separation for Oil/Water Emulsion Filtration

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2519
Author(s):  
Nafiu Umar Barambu ◽  
Muhammad Roil Bilad ◽  
Mohamad Azmi Bustam ◽  
Nurul Huda ◽  
Juhana Jaafar ◽  
...  
Keyword(s):  
Phase Separation ◽  
Surface Chemistry ◽  
Exposure Time ◽  
Membrane Fouling ◽  
Membrane Structure ◽  
Membrane Surface ◽  
Hydrophobic Membrane ◽  
Polysulfone Membrane ◽  
Water Emulsion ◽  
Oil Water

The discharge of improperly treated oil/water emulsion by industries imposes detrimental effects on human health and the environment. The membrane process is a promising technology for oil/water emulsion treatment. However, it faces the challenge of being maintaining due to membrane fouling. It occurs as a result of the strong interaction between the hydrophobic oil droplets and the hydrophobic membrane surface. This issue has attracted research interest in developing the membrane material that possesses high hydraulic and fouling resistance performances. This research explores the vapor-induced phase separation (VIPS) method for the fabrication of a hydrophilic polysulfone (PSF) membrane with the presence of polyethylene glycol (PEG) as the additive for the treatment of oil/water emulsion. Results show that the slow nonsolvent intake in VIPS greatly influences the resulting membrane structure that allows the higher retention of the additive within the membrane matrix. By extending the exposure time of the cast film under humid air, both surface chemistry and morphology of the resulting membrane can be enhanced. By extending the exposure time from 0 to 60 s, the water contact angle decreases from 70.28 ± 0.61° to 57.72 ± 0.61°, and the clean water permeability increases from 328.70 ± 8.27 to 501.89 ± 8.92 (L·m−2·h−1·bar−1). Moreover, the oil rejection also improves from 85.06 ± 1.6 to 98.48 ± 1.2%. The membrane structure was transformed from a porous top layer with a finger-like macrovoid sub-structure to a relatively thick top layer with a sponge-like macrovoid-free sub-structure. Overall results demonstrate the potential of the VIPS process to enhance both surface chemistry and morphology of the PSF membrane.

Preparation and Characterizations of Polysulfone Flat Ultrafiltration Membranes

2011 ◽  
Vol 418-420 ◽  
pp. 169-172
Author(s):  
Shan Zhang ◽  
Zhen Liu
Keyword(s):  
Pure Water ◽  
Water Flux ◽  
Bath Temperature ◽  
Coagulation Bath ◽  
Egg Rejection ◽  
Evaporation Time ◽  
Ultrafiltration Membranes ◽  
Pure Water Flux ◽  
Coagulation Bath Temperature

The Polysulfone Flat ultrafiltration membranes were prepared with dimethylacetamide (DMAc) as solvent and polyvinypyrrolidone (PVP) as pore forming additive. Performance of PSF membrane such as pure water flux, albumin egg rejection were investigated. In addition, the same investigations were conducted with different coagulation bath temperature and evaporation time. The results show that there were a maximum of pure water flux and a minimum of the retention of Albumin when PVP content reach 14%.

scholarly journals Effect of sonochemical synthesized TiO2 nanoparticles and coagulation bath temperature on morphology, thermal stability and pure water flux of asymmetric cellulose acetate membranes prepared via phase inversion method

2012 ◽  
Vol 18 (3) ◽  
pp. 385-398 ◽  
Author(s):  
Reza Abedini ◽  
Mahmoud Mousavi ◽  
Reza Aminzadeh
Keyword(s):  
Thermal Stability ◽  
Tio2 Nanoparticles ◽  
Phase Inversion ◽  
Pure Water ◽  
Water Flux ◽  
Composite Membranes ◽  
Bath Temperature ◽  
Coagulation Bath ◽  
Pure Water Flux ◽  
Coagulation Bath Temperature

In this study, asymmetric pure CA and CA/ TiO2 composite membranes were prepared via phase inversion by dispersing TiO2 nanopaticles in the CA casting solutions induced by immersion precipitation in water coagulation bath. TiO2 nanoparticles, which were synthesized by the sonochemical method, were added into the casting solution with different concentrations. Effects of TiO2 nanoparticles concentration (0 wt. %, 5wt.%, 10wt.%, 15wt.%, 20wt.% and 25wt.%) and coagulation bath temperature (CBT= 25?C, 50?C and 75?C) on morphology, thermal stability and pure water flux (PWF) of the prepared membranes were studied and discussed. Increasing TiO2 concentration in the casting solution film along with higher CBT resulted in increasing the membrane thickness, water content (WC), membrane porosity and pure water flux (PWF), also these changes facilitate macrovoids formation. Thermal gravimetric analysis (TGA) shows that thermal stability of the composite membranes were improved by the addition of TiO2 nanopaticles. Also TGA results indicated that increasing CBT in each TiO2 concentration leads to the decreasing of decomposition temperature (Td) of hybrid membranes.

scholarly journals Study of polyamide-6 hollow fiber membranes prepared via a thermally induced phase-separation method

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhao-Hui Jiang ◽  
Chang-Fa Xiao ◽  
Xiao-Yu Hu
Keyword(s):  
Hollow Fiber ◽  
Pure Water ◽  
Polymer Concentration ◽  
Water Flux ◽  
Bath Temperature ◽  
Coagulation Bath ◽  
Hollow Fiber Membranes ◽  
Fiber Membranes ◽  
Pure Water Flux ◽  
Coagulation Bath Temperature

AbstractHollow fiber membranes of polyamide-6(PA6) with porous structure were prepared by a thermally induced phase-separation method. N-Ethyl-o/p-toluene sulfonamide was chosen as diluent. On the basis of scanning electron microscopy (SEM) images, porosity, bubble point pore diameter and pure water flux, the influential factors including polymer concentration, coagulation bath temperature, post-stretching were investigated. The results indicate that with the increasing of PA6 concentration ‘slit-shaped’ pores in inner surfaces and cellular structure in cross-sections disappear, correspondingly, the properties of membranes such as porosity and pure water flux become poor. As the coagulation bath temperature varied from 20 °C to 50°C, the pure water flux of membranes is improved from 136 to 244 L·m-2·h-1. Post-stretching make the ‘interfacial micro-pores’ expand due to ‘stress concentration’ phenomenon, thus changing the structure and improving the properties of membranes. PA6 hollow fiber membranes with rational structure and high performance could be obtained by altering polymer concentration, coagulation bath temperature and post-stretching.

PHASE INVERSION PREPARATION AND MORPHOLOGICAL STUDY OF POLYVINYLIDENE FLUORIDE ULTRAFILTRATION MEMBRANE MODIFIED BY NANO-SIZED ALUMINA

2009 ◽  
Vol 02 (03) ◽  
pp. 113-119 ◽  
Author(s):  
A. M. BAZARGAN ◽  
Z. GHOLAMVAND ◽  
M. NAGHAVI ◽  
M. R. SHAYEGH ◽  
S. K. SADRNEZHAAD
Keyword(s):  
Polyvinylidene Fluoride ◽  
Phase Inversion ◽  
Membrane Surface ◽  
Bath Temperature ◽  
Contact Angles ◽  
Coagulation Bath ◽  
Alumina Powder ◽  
Effective Parameters ◽  
Precipitation Bath ◽  
Cross Sectional

In this study, polyvinylidene fluoride (PVDF) membranes with various structures ranging from dense to highly asymmetric morphologies were obtained by changing the effective parameters in the phase inversion process. The effect of some important processing parameters such as solution concentration, harshness of the precipitation bath, exposure time before immersion in coagulation bath and bath temperature was studied and the mentioned parameters were optimized. The membranes were then modified with nano-sized alumina powder in order to improve the hydrophilicity of the PVDF membranes. The surface morphology, surface and cross-sectional structures of the membranes were examined by scanning electron microscope (SEM) and atomic force microscope (AFM). The specific surface area of the membranes was determined using the Brunauer–Emmett–Teller (BET) method. The contact angles between water and the membranes' surfaces were measured in order to study the hydrophilicity changes of the membrane surface. The results indicated that the addition of nano-sized alumina to the casting dope increased the hydrophilicity of the PVDF membrane surface.

Preparation Process of Glass Membrane Using Non-Solvent Induced Phase Separation

2016 ◽  
Vol 680 ◽  
pp. 297-300 ◽  
Author(s):  
Ya Bin Zhang ◽  
Guang You Pan ◽  
Ya Ping Zhao ◽  
Jia Wei Xu ◽  
Hai Tao Feng
Keyword(s):  
Aqueous Solution ◽  
Phase Separation ◽  
Water Content ◽  
Calcination Temperature ◽  
Glass Powder ◽  
Bath Temperature ◽  
Coagulation Bath ◽  
Preparation Process ◽  
Glass Membrane ◽  
Coagulation Bath Temperature

The glass membrane was fabricated by non-solvent-induced phase separation (NIPS) and sintering technique. The preparation process was studied. PVDF was dissolved into DMAc completed. Subsequently, the used glass powder was added into above aqueous solution. The obtained slurry was tape-casted and a green membrane formed. The green membrane was immersed into coagulation bath. The exchange between DMAc and water in coagulation bath took place, and PVDF-containing glass membrane was obtained. The membrane was calcined at different temperature, and the glass membrane was prepared. In order to evaluate the porosity of membrane, many factors including water content in coagulation bath, PVDF content in slurry, coagulation bath temperature and calcination temperature were studied. The viscosity of slurry and shrinkage of membrane after calcination were also studied.

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