scholarly journals Novel Dopamine-Modified Cellulose Acetate Ultrafiltration Membranes with Improved Separation and Antifouling Performances

Author(s):  
Xi Ma ◽  
Hanxiang Guo ◽  
Zhaofeng Wang ◽  
Nan Sun ◽  
Pengfei Huo ◽  
...  

Abstract Cellulose derivatives are the earliest and most widely used membrane materials due to its many excellent characteristics, especially chemical activity and biodegradability. However, the hydrophobic properties of cellulose acetate (CA) limited its development to some extent. To improve the inherent hydrophobic and antifouling properties of the CA membrane, CA was successfully modified with dopamine (CA-2,3-DA) through selective oxidation and Schiff base reactions in this work, which was confirmed by 1H NMR and FTIR measurements. And then, the CA-2,3-DA membrane with high water permeability and the excellent antifouling property was prepared by the phase inversion method. Compared with the primordial CA membrane, the CA-2,3-DA membrane maintained a higher rejection rate for BSA (92.5%) while greatly increasing the pure water flux (167.3 L/m2h), which could be overcome the trade-off relationship between selectivity and permeability of the traditional CA membrane to a certain extent. According to the three-cycles dynamic ultrafiltration and static protein adsorption experiments, the CA-2,3-DA membrane showed good long-term performance stability and superior antifouling performance, which was supported by the experiment results including filtration resistance, flux decline ratio and flux recovery ratio. It is expected that this approach can greatly expand the high-value utilization of modified natural organic polysaccharides in separation engineering.

2013 ◽  
Vol 681 ◽  
pp. 309-313
Author(s):  
Dong Hua Zhang ◽  
Li Jing Pan ◽  
Da Zhi Sun

BaBi2Nb2O9/PVDF (polyvinylidene fluoride) composite ultrafiltration (UF)membranes were prepared by alloying BaBi2Nb2O9 (BBN) particles uniformly in the PVDF solution (15% polymer weight) and used a phase-inversion method. This paper studied the effect of the concentration of BBN from 0% to 5% in 0.2Mpa on pure water flux and rejection rate to Bovine serum albumin (BSA). The cross-sectional structures of composite membranes were observed by scanning electron microscopy (SEM). Moreover, XRD results revealed the crystal structure of PVDF. The experimental results showed that the BBN/PVDF composite ultrafiltration membranes were superior in separation performances than the pure PVDF membranes due to the addition of BBN.


2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Muhamad Zaini Yunos ◽  
Zawati Harun ◽  
Hatijah Basri ◽  
Mohd Fikri Shohur ◽  
Mohd Riduan Jamalludin ◽  
...  

The influence of zinc oxide and silver (I) oxide in polysulfone ultrafiltration membrane was studied. The membranes were prepared via phase inversion method. The morphology, surface roughness, hydrophillicity and antibacterial properties of membrane were investigated using SEM, AFM and contact angle device consecutively. It was found that membrane with zinc oxide additive has excellent pure water flux as compared to silver (I) oxide. However silver (I) oxide has better humic acid rejection due to the tradeoff effect. SEM-EDX for PSf/silver (I) oxide reveals that the accumulation of silver on top area in cross section of membrane while for zinc oxide seems more concentrated on the bottom. Interestingly, the AFM results support the previous result when PSf/zinc oxide showed better surface roughness on the top of the membrane. Eventhough zinc oxide is known one of antibacterial material, however from qualitative experiment using disc diffusion test (e-coli), there is no inhibition ring for PSf/zinc oxide membrane as compared to membrane with PSf/silver (I) oxide membrane which shows excellence inhibition ring.


2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Zawati Harun ◽  
Mohd Riduan Jamalludin ◽  
Hatijah Basri ◽  
Muhamad Fikri Shohur ◽  
Nurafiqah Rosman ◽  
...  

This study investigates the effects of synthetic silica(SiO2)with different weight percentage concentrations on the morphology and performance of the polysulfone (PSf) and polyethelene glycol (PEG) based membrane ultrafiltration (UF). Phase inversion method was used to prepare PSf/PEG ultrafiltration (UF) flatsheet membrane. SiO2 and N-Methyl 2 Pyrrolidone (NMP) were used as an additive and solvent respectively. The fabricated membrane was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and the performances of the membranes were measured in term of pure water flux by using distilled water and solute rejection at different wastewater concentration at 50%, 75% and 87.5%. The result showed that the addition of 2% silica in the dope solution increased the permeation in terms pure water flux and the best rejection with 62 Lm-2 h-1 and 89% (at 87.5 % waste water dilution) respectively


Author(s):  
Majed Alghamdi ◽  
Adel El-Zahhar

In this study the effects of graphene oxide (GO) nanosheets on the physicochemical properties and performances of cellulose acetate butyrate (CAB) membranes were investigated. Nanocomposite membranes were fabricated using Cand a small amount of GO in the range of 0 to 0.07 wt.%, using a conventional phase-inversion method. Membranes were characterized by different methods and their performances were tested using a dead-end filtration system. Compared with pristine Cmembrane, experimental results demonstrated an improvement in features such as hydrophilicity, permeability, salt rejection, antifouling, and stability. The results proved an increase in the porosity and pore sizes of membranes with GO addition. Furthermore, the membrane containing 0.07 wt.% of GO exhibited a low contact angle of 37? and a dramatic improvement in water flux of about 450% (from 2 to 11 L/m2 h). Moreover, it demonstrated a salt rejection of 39% for NaCl and 87% for Na2SO4, corresponding to improvements of about 144% and 93%, respectively. Furthermore, the results revealed a higher antifouling property with an 86% improvement in flux recovery and higher stability in terms of performance and thermal properties compared to CAB.


2021 ◽  
Vol 10 (1) ◽  
pp. 538-546
Author(s):  
Yanjun Lu ◽  
Yuxuan Ma ◽  
Tong Yang ◽  
Jifeng Guo

Abstract Modified polyvinylidene fluoride (PVDF) membranes were prepared by the phase inversion method via blending in situ formed nanosilver (Ag) and nanozirconium dioxide (ZrO2). Scanning electron microscopy of the membranes revealed that the surface pore size of the membranes was increased and distributed widely with the addition of modified nanosilver (Ag) and nanozirconium dioxide (ZrO2). The pores of the membrane were reduced due to excessive modification of the material when the content of zirconium dioxide was increased to 0.4%. XRD characterization showed that in situ synthesis of nanosilver (Ag) and nanozirconium dioxide (ZrO2) had been successfully blended in the membranes. The contact angle of the modified membrane ranged from 82.72° to 67.37°, which showed that the hydrophilic properties of the membrane were improved. The pure water flux of the modified membrane increased from 28.43 to 143.2 L/m2 h, indicating that the hydrophilicity of the modified membrane was enhanced significantly. The flux recovery rate of the modified membrane was obviously increased in the fouling experiment with BSA as the source of organic pollutants. The antimicrobial contamination of the membrane was greatly enhanced with the E. coli microbial contamination experiment.


2014 ◽  
Vol 981 ◽  
pp. 891-894 ◽  
Author(s):  
Yun Wei Guo ◽  
Wei Wei Cui ◽  
Wen Hua Xu ◽  
Yang Jiang ◽  
Hui Hui Liu ◽  
...  

This work describes the preparation and the properties of poly(vinylidene fluoride) (PVDF) porous membranes. The porous membrane was prepared using phase-inversion method by adding hydrophilic polyvinylpyrrolidone (PVP) as hole-agent. The contrastive analysis of membrane characterizations between the membrane no PVP added and the membrane added PVP were carried out by optical microscopy analysis, scanning electron microscopy, porosity, pure water flux and water contact angle. The results showed that adding PVP can induce the building of pore structure, increase the surface roughness and hydrophilicity of PVDF membrane, and then enhance its pure water flux.


2012 ◽  
Author(s):  
Ani Idris ◽  
Ka Yee Hew ◽  
Mieow Kee Chan

Dialisis membran yang mengandungi sellulosa asetat (CA) sebagai polimer, asid formik (FA) sebagai pelarut dan glukosa-D monohidrat sebagai bahan tambah telah disediakan melalui proses fasa balikan. Objektif utama bagi penyelidikan ini adalah untuk menyelidik pengaruh bahan tambah glukosa–D terhadap prestasi membran dialisis dari segi pemisahan urea dan kreatinina. Kepekatan glukosa–D diubah daripada 2 hingga 10 wt%. Pemanasan menggunakan ketuhar mikrogelombang yang dapat memendekkan masa pelarutan digunakan untuk melarutkan CA polimer dalam pelarut asid formik. Keputusan menunjukkan bahawa membran yang dihasilkan daripada 20 wt% selulosa asetat, 70 wt% asid formik dan 10 wt% glukosa–D monohidrat memberi prestasi yang terbaik bagi penyingkiran urea and kreatinina sebanyak masing–masimg 49.77% dan 19.54%. Apabila membran yang sama dikaji bagi penahanan BSA, ia memberikan peratus penyingkiran larutan BSA sebanyak 96.78%. Berbanding dengan membran dialisis selulosa asetat komersial, didapati bahawa keputusan adalah memuaskan. Gambar SEM menunjukkan bahawa penambahan glukosa–D monohidrat dalam larutan memberi pembentukan struktur jejari. Kata kunci: Membran dialisis; selulosa asetat; penyingkiran urea; penyingkiran kreatinina; peratus penahanan BSA Dialysis membrane containing cellulose acetate (CA) as polymer, formic acid (FA) as solvent and D–glucose monohydrate as additive was prepared by phase inversion method. The main objective of this study is to investigate the influence of D–glucose monohydrate as an additive on the performance of dialysis membrane in terms of urea and creatinine clearance. The concentration of D–glucose is varied from 2 to 10 wt%. Microwave heating which is capable of reducing dissolution time was used to dissolve the CA polymer in the formic acid solvent. Results revealed that the membrane produced from the 20 wt% cellulose acetate, 70 wt% formic acid and 10 wt% D–glucose monohydrate gives the best performance with urea and creatinine clearance of 49.77% and 19.54% respectively. When testing the same membranes with BSA solutions, it gives a BSA rejection rate as high as 96.78%, which seems to be comparable with the commercial cellulose acetate dialysis membranes. Membrane morphology was observed by using a scanning electron microscopy (SEM). The SEM images illustrated that the increment of D–glucose monohydrate in casting solution tends to promote macrovoid formation. Key words: Dialysis membrane; cellulose acetate; SEM images; urea clearance; creatine clearance; BSA rejection rate


2018 ◽  
Vol 2017 (2) ◽  
pp. 329-339 ◽  
Author(s):  
Sevgi Güneş-Durak ◽  
Türkan Ormancı-Acar ◽  
Neşe Tüfekci

Abstract In this study, four different membranes were fabricated by using polyetherimide and polyacrylonitrile polymers, N-methyl-2-pyrrolidone and polyvinylpyrrolidone (PVP) via phase inversion method to improve the membrane performance in fruit juice wastewater (FJWW) treatment. The addition of PVP to the casting solution increased membrane hydrophilicity, water content, contact angle, porosity, Fourier transform infrared spectroscopy peaks, membrane thickness, average roughness and viscosity of cast solutions compared to the bare membrane. It can be said that the addition of a lower polymer concentration and PVP intensively increases the pure water flux of the membrane. However, as the flux increased, a small decrease in FJWW rejection was observed.


2018 ◽  
Vol 55 (1) ◽  
pp. 95-98 ◽  
Author(s):  
Laurentia Geanina Tiron ◽  
Stefan Catalin Pintilie ◽  
Andreea Liliana Lazar ◽  
Maria Vlad ◽  
Stefan Balta ◽  
...  

Water is an important element of life, while every industry in its processes uses an important amount of water. Following processes, the water is contaminated and requires water treatment technologies. Unconventional methods to wastewater treatment, in the last years, use membrane technology as one of the most reliable processes for contaminants removal. In this article, the influence of the different concentrations of polysulfone (PSf) on the polymeric membranes properties was studied. These membranes were obtained through phase inversion method and with different polymer concentrations: 23, 25, 27 and 30 wt.%. The performance of the membranes was studied by pure water flux, permeability and retention. It has been observed that by increasing the polymer concentration, the pure water flux and the permeability will decrease. Retention was determined using methylene blue, which is one of the most utilized dye from industry and it could be observed that by increasing the polymer concentration the retention degree of the pollutant also increases. In order to explain the evolution of membrane permeability at different polymer concentrations, surface hydrophilicity by contact angle method and cross-section SEM imaging were used.


2011 ◽  
Vol 675-677 ◽  
pp. 391-394
Author(s):  
Shuai Li ◽  
Yuan Gao ◽  
Lu Bai ◽  
Wei Qian Tian ◽  
Li Ping Zhang

Nanocrystalline cellulose (NCC) was used to improve hydrophilic property and permeability of polysulfone (PS) membrane. It was prepared from cellulose pulp by acid-catalyzed hydrolysis and high-pressure homogenization. The casting solution of a PS/NCC blend was obtained by adding NCC to a PS membrane solution and the composite membrane was prepared by phase-inversion method. In addition, the concentration of NCC was increased gradually from 0 wt% to 1.1 wt% during the preparation in order to examine the pure water flux and the retention of a bovine serum albumin (BSA). Simultaneously, the porosity and mean pore size of the membrane was detected and calculated. The result showed that the capacity for ultrafiltration was enhanced with appropriate NCC content. The membranes were also observed with atomic force microscopy (AFM) and scanning electron microscopy (SEM) to explore their porous structures.


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