scholarly journals Fabrication and Characterization of Sulfonated Graphene Oxide (SGO) Doped PVDF Nanocomposite Membranes with Improved Anti-Biofouling Performance

Membranes ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 749
Author(s):  
Muhammad Zahid ◽  
Tayyaba Khalid ◽  
Zulfiqar Ahmad Rehan ◽  
Talha Javed ◽  
Saba Akram ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Pure Water ◽  
Thermo Gravimetric Analysis ◽  
Water Flux ◽  
Inversion Method ◽  
Gravimetric Analysis ◽  
X Rays ◽  
Nanocomposite Membranes ◽  
Sulfonated Graphene ◽  
Bsa Rejection

Emergence of membrane technology for effective performance is qualified due to its low energy consumption, no use of chemicals, high removal capacity and easy accessibility of membrane material. The hydrophobic nature of polymeric membranes limits their applications due to biofouling (assemblage of microorganisms on surface of membrane). Polymeric nanocomposite membranes emerge to alleviate this issue. The current research work was concerned with the fabrication of sulfonated graphene oxide doped polyvinylidene fluoride (PVDF) membrane and investigation of its anti-biofouling and anti-bacterial behavior. The membrane was fabricated through phase inversion method, and its structure and morphology were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-rays diffraction (XRD) and thermo gravimetric analysis (TGA) techniques. Performance of the membrane was evaluated via pure water flux; anti-biofouling behavior was determined through Bovine Serum albumin (BSA) rejection. Our results revealed that the highest water flux was shown by M7 membrane about 308.7 Lm−2h−1/bar having (0.5%) concentration of SGO with improved BSA rejection. Furthermore, these fabricated membranes showed high antibacterial activity, more hydrophilicity and mechanical strength as compared to pristine PVDF membranes. It was concluded that SGO addition within PVDF polymer matrix enhanced the properties and performance of membranes. Therefore, SGO was found to be a promising material for the fabrication of nanocomposite membranes.

scholarly journals TiO2 Nanoparticle Filler-Based Mixed-Matrix PES/CA Nanofiltration Membranes for Enhanced Desalination

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 433
Author(s):  
Mehwish Batool ◽  
Amir Shafeeq ◽  
Bilal Haider ◽  
Nasir M. Ahmad
Keyword(s):  
Tio2 Nanoparticles ◽  
Thermo Gravimetric Analysis ◽  
Water Flux ◽  
Surface Generation ◽  
Precipitation Method ◽  
Inversion Method ◽  
Gravimetric Analysis ◽  
Mixed Matrix ◽  
Salt Rejection ◽  
Matrix Nanocomposite

Mixed-matrix nanocomposite (PES/CA/PVP) membranes were fabricated for water desalination by incorporating varying amount of titanium dioxide nanoparticles (TiO2 NPs) ranging from 0 and 2 wt. %. Efficient dispersion of nanoparticles within polymeric membranes was achieved using the chemical precipitation method for uniform surface generation, and an asymmetric morphology was achieved via phase inversion method. Finally, membranes were characterized by Fourier Transform Infrared (FTIR) spectroscopy, Thermo Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), porosity and contact angle analysis. FTIR confirmed chemical composition of membranes in terms of polymers (PES/CA/PVP) and TiO2. TGA analysis confirmed an increase in thermal stability of membranes with the increase of TiO2 nanoparticles loading. The addition of TiO2 nanoparticles also resulted in an increase in porous structures due to an increase in mean pore size, as shown by SEM results. An increase in the hydrophilicity of the membranes was observed by increasing the concentration of TiO2 nanoparticles. The present study investigated pristine and mixed-matrix nanocomposite NF membrane performance while filtering a NaCl salt solution at varying concentration range (from 1 to 4 g/Lit 6 bar). The prepared membranes demonstrated significant improvement in water permeability and hydrophilicity. Further, to optimize the water flux and salt rejection, the concentration of Polyvinylpyrrolidone (PVP) was optimized along with TiO2 nanoparticles. Both the water flux and salt rejection of the fabricated membranes were observed to increase with an increase inTiO2 nanoparticles to 2 wt. % loading with optimized PVP concentration, which demonstrated the improved desalination performance of resultant membranes.

Performance of PSf Ultrafiltration Membrane: Effect of Different Nonsolvent on Coagulation Medium

2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Muhamad Fikri Shohur ◽  
Zawati Harun ◽  
W. J. Lau ◽  
Muhamad Zaini Yunos ◽  
Mohd Riduan Jamalludin
Keyword(s):  
Pore Structure ◽  
Phase Inversion ◽  
Pure Water ◽  
Water Flux ◽  
Bottom Layer ◽  
Ultrafiltration Membrane ◽  
Coagulation Bath ◽  
Inversion Method ◽  
Asymmetric Membrane ◽  
Result Analysis

One of the big challenges in developing a good asymmetric membrane  is macrovoid formation that leads to reduction of rejection value.  The most common method to reduce or suppress macrovoid formation is by addition of controlled solvent to the coagulation bath. Therefore, the effect of difference coagulants based on dissolved KCl (monovalent) and dissolved Na2SO4(divalent) with different concentration onto asymmetric Polysulfone (PSf) ultrafiltration membrane was investigated in this work. The PSf ultrafiltration membranes were prepared by using phase inversion method using these two immerse aqueous solutions. The performances of membranes were evaluated via pure water flux (distilled water) and solute rejection (humic acid). Results on the cross section revealed that the structure of membrane show a straight pattern of bigger finger-like pore structure from top to bottom layer tend to reduce with at the same time the diameter of finger-like pore structure  also increased, as salt medium of coagulant increases. These obviously shown by permeation values for both salt mediums were higher compared to without salt coagulant. This reduction of finger-like structure at bottom layer occurred along together with the formation of sponge shape structure. The growth of thick sponge shape is strongly influence by kinetic phase inversion of salt coagulant that also creates resistance to permeation mechanism. However the intense salt coagulant medium can cause the bigger sponge structure that will slightly reduce rejection and increase the permeation.  This was proved by the rejection of KCl medium started to increase at 1-3% but slightly reduced at 4%. Based on the result analysis demonstrated that the ideal membrane with highest rejection and good permeation values was membrane immersed into 1% Na2SO4 coagulation medium.

Graphene oxide quantum dots incorporated nanocomposite membranes with high water flux for pervaporative dehydration

2018 ◽  
Vol 563 ◽  
pp. 903-913 ◽  
Author(s):  
Manru Wang ◽  
Fusheng Pan ◽  
Leixin Yang ◽  
Yimeng Song ◽  
Hong Wu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Graphene Oxide ◽  
Water Flux ◽  
High Water ◽  
Nanocomposite Membranes ◽  
Graphene Oxide Quantum Dots

SUPERCONDUCTIVITY IN THE Bi-Pb-Sr-Ca-Cu-O SYSTEM DOPED WITH Sb

1990 ◽  
Vol 04 (01) ◽  
pp. 131-141 ◽  
Author(s):  
J. HEIRAS ◽  
W. KRAUSS ◽  
C. POLITIS
Keyword(s):  
Transition Temperature ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
X Rays ◽  
Superconducting Transition ◽  
Melting Behaviour ◽  
Superconducting Properties ◽  
Thermo Gravimetric ◽  
Preparation Methods ◽  
Annealing Conditions

Doping of Bi-Pb-Sr-Ca-Cu-O HTSC's with Sb have been attempted with the purpose of increasing the transition temperature. Several different preparation methods were investigated in which the composition and annealing conditions were varied; ρ vs T and χ vs T measurements were carried out to determine the superconducting properties of samples. X-rays, differential thermal analysis (DTA) and thermo gravimetric analysis (TG) were performed to study the structure and the melting behaviour of samples. However, it was found that, at least for the conditions tested, Sb has no effect in increasing the transition temperature of this system. The maximum superconducting transition temperature observed in the system Bi 2−x Pb x Sr 2 Ca 2 Cu 3 O y was T c,o = 108 K which was completely independent of the doping with Sb.

scholarly journals Preparation and Solvents Effect Study of Asymmetric Cellulose Acetated/Polyethyleneimine Blended Membranes for Dialysis Application

2017 ◽  
Vol 2 (4) ◽  
pp. 5
Author(s):  
Hizba Waheed ◽  
Arshad Hussain
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Pure Water ◽  
Water Flux ◽  
Void Formation ◽  
Contact Angle Measurement ◽  
Effect Study ◽  
Angle Measurement ◽  
Urea Clearance ◽  
Bsa Rejection

The aim of this research is to study the effect of various solvents on membrane morphology and performance of cellulose acetate (CA) based polymeric membranes having Polyetyleneimine (PEI) additive. The CA/PEI blended membranes are to be used for dialysis operation. For this purpose, acetic acid, formic acid, 1-Methyl-2-pyrolidone (NMP) and N, N-Dimethylacetamide (DMAC) are used. The best performing membrane is selected and is modified using various solvents to choose the best solvent that can enhance the membrane performance efficiently. Afterwards contact angle measurement, pure water flux and water up take of modified membranes are determined to check the change in dialysis performance. Surface morphology of membrane is studied using SEM and AFM. All these results displayed blending of polymer, solvents and additive in different ways. All prepared membranes were also tested for bovine serum albumin (BSA) rejection and urea clearance. From all the solvents used, formic acid gave the best results. The blending is homogeneous and macro void formation is appropriate for dialysis application.  The replacement of acetic acid with formic acid (C.A+ F.A+PEI) showed hydrophilic nature and increased the BSA rejection percentage. Urea clearance was augmented as well to an appreciable value. The results revealed that from all the mentioned above solvents, formic acid is most suitable one for dialysis operation.

scholarly journals Graphene Oxide Incorporated Polysulfone Substrate for Flat Sheet Thin Film Nanocomposite Pressure Retarded Osmosis Membrane

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 416
Author(s):  
Siti Nur Amirah Idris ◽  
Nora Jullok ◽  
Woei Jye Lau ◽  
Hui Lin Ong ◽  
Cheng-Di Dong
Keyword(s):  
Thin Film ◽  
Graphene Oxide ◽  
Polymer Matrix ◽  
Water Flux ◽  
Weight Percent ◽  
Inversion Method ◽  
High Porosity ◽  
Pressure Retarded Osmosis ◽  
Flat Sheet ◽  
Thin Film Nanocomposite

This study focuses on the development of flat sheet thin film nanocomposite (TFN) pressure retarded osmosis (PRO) membranes for the enhancement of osmotic power generation by the incorporation of laboratory-synthesised graphene oxide (GO) into the polysulfone (PSf) polymer matrix. A series of membranes containing different weight percent of GO (0, 0.1, 0.25, 0.5 and 1.0 wt%) were fabricated via a phase inversion method with polyethylene glycol (PEG) as the pore forming agent. The results show that the TFN-0.25GO membrane has excellent water flux, salt reverse flux, high porosity and an enhanced microvoids morphology compared to the control membrane. The highest power density was achieved when TFN-0.25GO was used is 8.36 Wm−2 at pressure >15 bar. It was found that the incorporation of GO into the polymer matrix has significantly improved the intrinsic and mechanical properties of the membrane.

Preparation and Properties of Tea Polyphenol Modified Graphene Oxide/Epoxy Resin Composites

2019 ◽  
Vol 814 ◽  
pp. 3-11
Author(s):  
Xiang Yu Ren ◽  
Hui Chen ◽  
Jing Wu ◽  
Hong Bo Liu
Keyword(s):  
Graphene Oxide ◽  
Epoxy Resin ◽  
Thermo Gravimetric Analysis ◽  
Testing Machine ◽  
Gravimetric Analysis ◽  
Resin Composites ◽  
X Ray ◽  
Modified Graphene Oxide ◽  
Epoxy Resin Composites ◽  
Modified Graphene

Microcrystalline graphite (MG) was used as raw material and oxidated by Hummers method. And further the graphene oxide (GO) was obtained by ultrasonic stripping. The TP modified graphene (TPG) was prepared by the surface grafting of pure natural green tea extract tea polyphenols (TP) on the surface of GO. Finally, the TPG/epoxy resin composite was prepared by solution blending and heat-curing moulding method.The characterization of structure and properties of TPG was analyzed by X ray diffraction pattern (XRD), infrared spectroscopy (FT-IR), thermo gravimetric analysis (TGA) and X ray photoelectron spectroscopy (XPS). A universal material testing machine was used to test the mechanical properties of epoxy resin composites with different addition of TPG. Field emission scanning electron microscopy (SEM) was used to observe the tensile-sectional morphology of the composites. The thermal stability of the composites was investigated by thermogravimetry and thermal dilatometer. The experimental results showed that the TP molecule was successfully grafted on the oxygen-containing functional groups of the GO surface through the phenolic hydroxyl group.When the addition of TPG was 1.0 wt%, the decomposition temperature of the epoxy resin was increased by 22.2 °C,and the surface resistivity decreased from 1.35×1014 Ω·m to 1.7×109 Ω·m. When the added amount of TPG was 0.5 wt%, the tensile strength of composites was increased by 13.5% reaching 59.85 MPa.

Study of antifouling modified ultrafiltration membrane based on the secondary treated water of urban sewage

2012 ◽  
Vol 66 (10) ◽  
pp. 2074-2082 ◽  
Author(s):  
Xiao-rong Meng ◽  
Liang Zhao ◽  
Lei Wang ◽  
Xu-dong Wang ◽  
Dan-xi Huang ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Layer Structure ◽  
Pure Water ◽  
Water Flux ◽  
Inversion Method ◽  
Treated Water ◽  
Urban Sewage ◽  
Cake Layer ◽  
Modified Membrane ◽  
Section Structure

Mixtures of polyvinylidene fluoride (PVDF) and polyvinyl alcohol (PVA) containing hydrophilic ultrafiltration membranes were prepared by adding PVA (5 to 30%) to PVDF by the phase inversion method. The hydrophilic contact angle (CA), equilibrium water content, pure water flux and bovine serum albumin retention were studied to assess the membrane performance. The anti-fouling performance of modified membrane to the secondary treated water was evaluated by flux decline, washing recovery rate and fouling resistance analysis. Scanning electron microscopy showed that the cross-section structure of the membranes had finger-like pores, which were well developed and uniformly distributed, and the sub-layer structure was looser and more porous with the increasing content of PVA. The CA gradually decreased. The steady flux was 800 L/m2 h from P15 to P30, and the BSA retention sharply declined. The ultrafiltration tests for secondary treated water indicated that the main fouling source of the modified membrane was the concentration polarization and cake layer resistance. After physical flushing, the flux recovery ratio of the membrane could reach 100% when the PVA content was 5–15%, which shows excellent anti-pollution performance and good prospects for use in processing wastewater from urban sewage.

Influence of Inorganic Additives on the Performance of Polysulfone Ultrafiltration Membrane

2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Muhamad Zaini Yunos ◽  
Zawati Harun ◽  
Hatijah Basri ◽  
Mohd Fikri Shohur ◽  
Mohd Riduan Jamalludin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Zinc Oxide ◽  
Pure Water ◽  
Water Flux ◽  
Antibacterial Properties ◽  
Ultrafiltration Membrane ◽  
Inversion Method ◽  
Pure Water Flux ◽  
Phase Inversion Method ◽  
Oxide Membrane

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.

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