scholarly journals Surface modification of polyvinylidene fluoride (PVDF) membrane via radiation grafting: novel mechanisms underlying the interesting enhanced membrane performance

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Liguo Shen ◽  
Shushu Feng ◽  
Jianxi Li ◽  
Jianrong Chen ◽  
Fengquan Li ◽  
...  
2021 ◽  
Author(s):  
Diba Mirriahi

The interest in using polyvinylidene fluoride (PVDF) membrane in order to separate casein and serum proteins has been raised due to its significant stability. However, the high hydrophobicity of PVDF membrane causes severe fouling during filtration processes. Ozonation, a surface modification process in which polar groups would be formed on the membrane surface, is widely known for its high efficiency. In the present study, the main objective was to optimize the ozonation parameters to reach the minimum fouling while the maximum mechanical strength could be retained. The contact angle of a water droplet on the membrane surface decreased from 73.5° to 50.4° after the treatment of the membrane at the optimal gaseous phase ozonation. This indicates an increase in the hydrophilicity of the treated membrane. Also, filtration performance demonstrated a lower fouling occurrence on the treated membrane as compared to the untreated one. Although gaseous ozonation yielded a slightly better performance in comparison to the aqueous treatment, the membrane treated with aqueous phase ozonation was benefited from conserving its mechanical strength. Activated carbon helped decreasing the contact angle and fouling as compared to the non-catalytic aqueous treatment while the tensile strength was not affected


2021 ◽  
Author(s):  
Diba Mirriahi

The interest in using polyvinylidene fluoride (PVDF) membrane in order to separate casein and serum proteins has been raised due to its significant stability. However, the high hydrophobicity of PVDF membrane causes severe fouling during filtration processes. Ozonation, a surface modification process in which polar groups would be formed on the membrane surface, is widely known for its high efficiency. In the present study, the main objective was to optimize the ozonation parameters to reach the minimum fouling while the maximum mechanical strength could be retained. The contact angle of a water droplet on the membrane surface decreased from 73.5° to 50.4° after the treatment of the membrane at the optimal gaseous phase ozonation. This indicates an increase in the hydrophilicity of the treated membrane. Also, filtration performance demonstrated a lower fouling occurrence on the treated membrane as compared to the untreated one. Although gaseous ozonation yielded a slightly better performance in comparison to the aqueous treatment, the membrane treated with aqueous phase ozonation was benefited from conserving its mechanical strength. Activated carbon helped decreasing the contact angle and fouling as compared to the non-catalytic aqueous treatment while the tensile strength was not affected


RSC Advances ◽  
2015 ◽  
Vol 5 (19) ◽  
pp. 14147-14155 ◽  
Author(s):  
A. Moslehyani ◽  
A. F. Ismail ◽  
M. H. D. Othman ◽  
T. Matsuura

This paper focuses on the potential of a novel flat sheet nanocomposite titanium dioxide (TiO2)-halloysite nanotubes (HNTs)/polyvinylidene fluoride (PVDF) membrane as a photocatalytic separator in the photocatalytic membrane reactor (PMR).


2012 ◽  
Vol 209-211 ◽  
pp. 1571-1575 ◽  
Author(s):  
Xiao Na Wu ◽  
Liang Wang ◽  
Zhao Hui Zhang ◽  
Wen Yang Li ◽  
Xing Fei Guo

Carbon dioxide (CO2) absorption performance from flue gas was investigated using monoethanolamine (MEA) solution in porous hydrophobic polyvinylidene fluoride (PVDF) hollow fiber membranes contactor. The influence of operating parameters on CO2 removal efficiency and flux were studied in the immersion operating mode. The experimental results indicated that the CO2 removal efficiency and flux decreased with the increase of flue gas load and carbonization degrees, but the increase of the absorbent concentration and temperature promoted membrane performance of CO2 capture. An increase of 84 m3•m-2•h-1 in the flue gas load resulted in a 68% decrease in the removal efficiency. Absorbent carbonation degree increased to 0.45 mol CO2•mol-1MEA led to the decrease of active ingredient amounts in the absorption solution, and the corresponding removal efficiency and membrane flux dropped by 50% of the initial amounts, respectively. The increase of concentration and temperature of absorbent also benefited membrane absorption performance of CO2 absorption, so that the concentration and temperature of the solvent increased lead to the CO2 removal efficiency and flux increased.


Membranes ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 121
Author(s):  
Shengli Wang ◽  
Xin Lu ◽  
Lanhe Zhang ◽  
Jingbo Guo ◽  
Haifeng Zhang

In this study, the properties of the initial fouling layer on the membrane surface of a bioreactor were investigated under different operating modes (with or without permeate flux) to improve the understanding of the effect of permeation drag on the formation of the initial fouling layer. It was found that protein was the major component in the two types of initial fouling layers, and that the permeation drag enhanced the tryptophan protein-like substances. The attraction of the initial foulants to the polyvinylidene fluoride (PVDF) membrane was ascribed to the high zeta potential and electron donor component (γ−) of the membrane. Thermodynamic analyses showed that the permeation drag-induced fouling layer possessed high hydrophobicity and low γ−. Due to permeation drag, a portion of the foulants overcame an energy barrier before they contacted the membrane surface, which itself possessed a higher fouling propensity. A declining trend of the cohesive strength among the foulants was found with the increasing development of both fouling layers.


2011 ◽  
Vol 295-297 ◽  
pp. 286-291
Author(s):  
Li Guo Wang ◽  
Xiao Guang Zhang ◽  
Shu Fang Hou ◽  
Xiu Ju Wang ◽  
Ai Min Wang ◽  
...  

Hydrophilic polyvinylidene fluoride (PVDF) flat ultrafiltration membranes were prepared by wet-spinning method. The effects of technical parameters of maleic anhydride grafted onto PVDF on the performance of hydrophilic PVDF membranes were investigated, the preparation technical parameters were determined, and the hydrophilic PVDF flat membranes were prepared. Then, hydrophilic PVDF membranes were characterized in terms of pure water flux, contact angle, infrared spectroscopic analysis and scanning electron microscope(SEM). The results showed that maleic anhydride had been grafted onto PVDF, and the hydrophilic performance of the modified membrane was better than the traditional one.


2015 ◽  
Vol 35 (4) ◽  
pp. 339-347
Author(s):  
Abdul L. Ahmad ◽  
Norhidayah Ideris ◽  
Ooi Boon Seng ◽  
Low Siew Chun ◽  
Asma Ismail

Abstract The correlation between the behavior of a polyvinylidene fluoride (PVDF) membrane toward protein binding at different physicochemical environments was investigated. The PVDF membrane was first fabricated and characterized to understand its morphological, polymorph and intrinsic characteristics. The results confirmed that the membrane had a microporous, symmetric structure and high hydrophobicity and electronegativity. The membrane was further tested under different physicochemical environments by modifying the type of protein and pH medium used. The results showed that different proteins and pH values contribute to different membrane-protein binding mechanisms. Overall, the results of PVDF membrane-protein binding were satisfactory and demonstrated the ability of the membrane to capture various proteins or reagents.


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