scholarly journals Enhancing the Antibacterial Properties of PVDF Membrane by Hydrophilic Surface Modification Using Titanium Dioxide and Silver Nanoparticles

Membranes ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 289
Author(s):  
Kajeephan Samree ◽  
Pen-umpai Srithai ◽  
Panaya Kotchaplai ◽  
Pumis Thuptimdang ◽  
Pisut Painmanakul ◽  
...  

This work investigates polyvinylidene fluoride (PVDF) membrane modification to enhance its hydrophilicity and antibacterial properties. PVDF membranes were coated with nanoparticles of titanium dioxide (TiO2-NP) and silver (AgNP) at different concentrations and coating times and characterized for their porosity, morphology, chemical functional groups and composition changes. The results showed the successfully modified PVDF membranes containing TiO2-NP and AgNP on their surfaces. When the coating time was increased from 8 to 24 h, the compositions of Ti and Ag of the modified membranes were increased from 1.39 ± 0.13 to 4.29 ± 0.16 and from 1.03 ± 0.07 to 3.62 ± 0.08, respectively. The water contact angle of the membranes was decreased with increasing the coating time and TiO2-NP/AgNP ratio. The surface roughness and permeate fluxes of coated membranes were increased due to increased hydrophilicity. Antimicrobial and antifouling properties were investigated by the reduction of Escherichia coli cells and the inhibition of biofilm formation on the membrane surface, respectively. Compared with that of the original PVDF membrane, the modified membranes exhibited antibacterial efficiency up to 94% against E. coli cells and inhibition up to 65% of the biofilm mass reduction. The findings showed hydrophilic improvement and an antimicrobial property for possible wastewater treatment without facing the eminent problem of biofouling.

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).


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.


2015 ◽  
Vol 6 (2) ◽  
pp. 280-289
Author(s):  
Baoli Shi ◽  
Zheng Li ◽  
Xing Su

A UV photo-grafting method was utilised to enhance the hydrophilicity and anti-fouling property of self-made poly(vinylidene fluoride) (PVDF) ultrafiltration membranes. N,N′-methylene-bisacrylamide (MBAA) was used as monomer and Ce(IV) was used as initiator to obtain balance between grafting treatment consumption and enhanced performance. MBAA could be grafted onto the surface of pure PVDF membranes through a water-phase grafting method under UV photoradiation. When the MBAA concentration was 0.07 mol/L, the Ce(IV) concentration was 0.04 mol/L, and the irradiation duration was 3 min, the membrane surface was grafted with a sufficient amount of monomer under a UV photoradiation intensity of 5.0 mW/cm2. The water contact angle on the surface of the modified membrane decreased by approximately 16°, and flux recovery increased by approximately 40% compared with the pure PVDF membrane when treating river water. For bovine serum albumin rejection and porosity measurements no significant changes were observed between pure PVDF and graft-treated membranes. The enhanced performance of the modified membrane in this work was moderate, but the UV irradiation duration (3 min) was short. The integrative effects of UV modification in this work were satisfactory when both irradiation duration and enhanced performance were considered.


Author(s):  
Kefan Jiang ◽  
◽  
Hooman Chamani ◽  
Takeshi Matsuura ◽  
Dipak Rana ◽  
...  

Membrane distillation (MD) is a thermally driven separation process. Despite many advantages over other membrane separation processes, pore wetting hampers the wide commercial applications of the MD process. In this paper, the effect of temperature and presence (or absence) of salt in the feed solution on the wetting properties of commercial polyvinylidene fluoride (PVDF) membrane during a period of eight weeks was investigated. Liquid entry pressure (LEP) and water contact angle (WCA) were employed to characterize the wetting properties of the PVDF membrane. The result shows that the temperature has a significant impact on the decrease of the contact angle of the PVDF membrane.


2021 ◽  
Vol 18 (4) ◽  
pp. 1338
Author(s):  
Amer Naji Al-Naemi ◽  
Mohammed Amer Abdul-Majeed ◽  
Mustafa H. Al-Furaiji ◽  
Inmar N Ghazi

Oily wastewater is one of the most challenging streams to deal with especially if the oil exists in emulsified form. In this study, electrospinning method was used to prepare nanofiberous polyvinylidene fluoride (PVDF) membranes and study their performance in oil removal. Graphene particles were embedded in the electrospun PVDF membrane to enhance the efficiency of the membranes. The prepared membranes were characterized using a scanning electron microscopy (SEM) to verify the graphene stabilization on the surface of the membrane homogeneously; while FTIR was used to detect the functional groups on the membrane surface. The membrane wettability was assessed by measuring the contact angle. The PVDF and PVDF / Graphene membranes efficiency was tested in separation of emulsified oil from aqueous solutions. The results showed that PVDF-Graphene nanofiber membrane exhibited better performance than the plain PVDF nanofiber membrane with average water flux of 210 and 180 L.m-2.h-1, respectively. Both membranes showed high oil rejection with more than 98%.


2021 ◽  
Vol 16 ◽  
pp. 155892502110660
Author(s):  
Cuihong Sheng ◽  
Limeng Yang ◽  
Hui Zhang ◽  
Pengfei Zhang ◽  
Guodong Shen

Superhydrophobic antibacterial cotton fabric can be widely applied in outdoor clothing, hospital bedding, and other fields. However, the existing manufacturing methods are difficult or complicated. Herein, a facile and straightforward fabrication strategy is proposed via a one-step hydrothermal method to construct micro-nanometer hierarchical structure with low surface energy on fabric. In an appropriate amount, 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (PFOTES) and tetrabutyl titanate (TBT) were mixed in a hydrothermal reactor to generate titanium dioxide. Meanwhile, the PFOTES agent was hydrolyzed and condensed, bonded with titanium dioxide, and finally grafted onto the fiber together. Morphology and elements results demonstrated that the fabric surface was covered by the TiO2 nanoparticles with superhydrophobic coating. The chemical bonds of Si-O-Ti, Ti-O-C, and Ti-O-Ti revealed the structural relationship between TiO2 with PFOTES and cotton fibers. The water contact angle of the fabric obtained can reach to 168°. The fluorinated-TiO2 cotton fabric showed high antibacterial properties in visible light against E. coli and S. aureus. This simple method of preparing superhydrophobic and antibacterial fabric exhibited great potential in the field of functional textiles such as outdoor garments and hospital-related applications.


2019 ◽  
Vol 9 (5) ◽  
pp. 855
Author(s):  
Tingting Li ◽  
Yong Gao ◽  
Junwo Zhou ◽  
Manying Zhang ◽  
Xiaofei Fu ◽  
...  

An improved photocatalytic microfiltration membrane was successfully prepared by the impregnation method with nitrogen-doped TiO2/graphene oxide (GO) (NTG). By utilizing the unique role of N and GO, the photocatalytic activity of the membrane in UV and sunlight was improved. Compared with the Polyvinylidene Fluoride (PVDF) microfiltration membrane which was modified by TiO2, N-TiO2 (NT) and TiO2-GO (TG), the NTG/PVDF membrane exhibited high photocatalytic efficiency and significantly improved photodegradation power to the methylene blue (MB) solution under ultraviolet light and sunlight, with the photocatalytic efficiency reaching 86.5% and 80.6%, respectively. Scanning electron microscopy (SEM), X-ray diffractometry (XRD) and Fourier transform infrared spectroscopy (FT-IR) were used to analyze the morphology, crystal structure and chemical bonds of the membrane surface. The hydrophilicity of the modified PVDF microfiltration membrane was significantly improved, the flux of the pure water membrane reached 1672 Lm−2h−1, the flux of the MB solution was also significantly improved due to photodegradation. Therefore, the nitrogen-doped titanium dioxide graphene oxide PVDF microfiltration membrane (NTG/PVDF membrane) has great development prospects in sustainable water treatment.


2013 ◽  
Vol 575-576 ◽  
pp. 265-269 ◽  
Author(s):  
Xiu Ju Wang ◽  
Xing Jie Lu ◽  
Wei Ying Xu ◽  
Jia Chen Zhu ◽  
Li Guo Wang

The 2-thiol benzothiazole was blended in Polyvinylidene fluoride (PVDF) membrane to prepare a kind of PVDF modified ultrafiltration membrane that could be used to remove mercury ion in water treatment. The water flux and retention rate of BSA of obtained PVDF modified ultrafiltration membrane was 222 L/m2·h and 92.33% respectively. The membrane performance were characterized by infrared spectroscopy (FT-IR) and water contact angle measurement. The results showed that, the PVDF modified membrane presented better adsorption ability for mercury ion than the traditional PVDF membrane. After 4 phases of adsorption/desorption, the modified membrane maintained a mercury ion adsorption amount of 0.264 mg/cm2and the desorption rate could reached 94%.


2019 ◽  
Vol 72 (6) ◽  
pp. 425 ◽  
Author(s):  
Pengzhi Bei ◽  
Hongjing Liu ◽  
Hui Yao ◽  
Yang Jiao ◽  
Yuanyuan Wang ◽  
...  

In order to enhance the hydrophobicity of polyvinylidene fluoride (PVDF) porous membranes, the blending of PVDF with a hydrophobic ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF6]) was carried out. The modified PVDF membranes with [Bmim][PF6] were fabricated through a non-solvent induced phase inversion using lithium chloride as a porogen in the PVDF casting solution. The effects of [Bmim][PF6] on the membrane characteristics were investigated. FT-IR analysis indicates that the IL is successfully retained by the PVDF membrane. Thermogravimetric analysis reveals that the optimum temperature of the modified membrane is below 300°C. Scanning electron microscopy pictures show that modified membranes have more homogeneous and larger diameter pores with a mean pore size of 0.521µm and porosity of 78%. By measuring the IL leaching during the membrane fabrication, it was found that the modified membrane does not lose IL. Atomic force microscopy shows that the roughness of the modified membrane surface increases slightly, but the contact angle of the modified membrane increases significantly from 88.1° to 110.1°. The reason for this is that the fluorine-containing IL has a low surface energy, which can enhance the hydrophobicity of the membrane. Finally, by comparing modified membranes with different IL concentrations, we draw a conclusion that the modified membrane with an IL concentration of 3 wt-% has the best properties of pore size, porosity, and hydrophobicity.


Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4099 ◽  
Author(s):  
Nasrul Arahman ◽  
Sri Mulyati ◽  
Afrillia Fahrina ◽  
Syawaliah Muchtar ◽  
Mukramah Yusuf ◽  
...  

The removal of impurities from water or wastewater by the membrane filtration process has become more reliable due to good hydraulic performance and high permeate quality. The filterability of the membrane can be improved by having a material with a specific pore structure and good hydrophilic properties. This work aims at preparing a polyvinylidene fluoride (PVDF) membrane incorporated with phospholipid in the form of a 2-methacryloyloxyethyl phosphorylcholine, polymeric additive in the form of polyvinylpyrrolidone, and its combination with inorganic nanosilica from a renewable source derived from bagasse. The resulting membrane morphologies were analyzed by using scanning electron microscopy. Furthermore, atomic force microscopy was performed to analyze the membrane surface roughness. The chemical compositions of the resulting membranes were identified using Fourier transform infrared. A lab-scale cross-flow filtration system module was used to evaluate the membrane’s hydraulic and separation performance by the filtration of humic acid (HA) solution as the model contaminant. Results showed that the additives improved the membrane surface hydrophilicity. All modified membranes also showed up to five times higher water permeability than the pristine PVDF, thanks to the improved structure. Additionally, all membrane samples showed HA rejections of 75–90%.


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