PVC Membrane Research Articles

Experimental study on burn through properties of PVC membrane room under fire

The thermal properties of PVC fabric membrane itself make it insufficient in fire resistance, and the overall stability of the membrane structure will be seriously threatened after a fire. In this paper, a small-size membrane burn-through test platform was designed and built, and the intermediate fire and corner fire tests were conducted to obtain smoke filling and membrane surface temperature law of change. Results showed that the softening and melting temperature of the membrane is about 164 °C, and the critical temperature of the membrane is about 257 °C. At the same time, the comparative analysis of the experiment and simulation results verified that the feasibility of Fire Dynamics Simulation to study the membrane structure fire.

PVC-g-PVP amphiphilic polymer synthesis by ATRP and its membrane separation performance for silicone-containing wastewater

Polyorganosiloxane (silicone)-contaminated wastewater is a typical chemical wastewater that causes serious environmental pollution, is difficult to treat and has a high separation cost due to its toxicity, high chemical stability, and low surface tension. To liminate this pollution, a low-cost ultrafiltration membrane with excellent separation properties was successfully fabricated. First, to prepare the membrane, an amphiphilic polymer of poly(vinyl chloride)-g-poly(vinyl pyrrolidone) (PVC-g-PVP) was synthesized by atom transfer radical polymerization (ATRP) over an inexpensive catalyst/ligand system of CuCl/benzyl dimethylamine (BDMA). Thereafter, the membrane was fabricated by regulating the aggregation of the PVC-g-PVP amphiphilic polymer in its casting solution by increasing the solution temperature. The surface smoothness and hydrophilicity of the resulting PVC-g-PVP membrane were better than those of the pristine PVC membrane. Furthermore, the separation and anti-fouling performances of the resulting membrane for silicone-contaminated wastewater were better than those of the pristine PVC membrane. The permeation flux presented an increment of approximately 233%, with a silicone rejection rate was of approximately 100%, and the flux recovery ratio of approximately 72.7% after three cycling tests, which was an increase of approximately 423%. The integration of inexpensive BDMA was used as ligand for the synthesis of PVC-g-PVP, and hydrophilic PVC-g-PVP membrane was fabricated by regulating the aggregation of the PVC-g-PVP in solution, this work provided a new way for the fabrication of amphiphilic polymer membrane with potential application in chemical wastewater remediation.

Investigation of fouling of surface modified Polyvinyl chloride hollow fiber membrane bioreactor via Zinc oxide-nanoparticles under coagulant for municipal wastewater treatment

In this study, hollow fiber PVC/ZnO-nanocomposite in an MBR was investigated for municipal wastewater treatment. The following parameter were evaluated: BOD, COD, TSS, NTU, TP, TKN. ZnO nanoparticles caused to decrease the contact angle from 78° to 67° for the neat PVC and 0.5 wt% ZNO-nanocomposite membrane, respectively. The majority of the neat membrane resistance was due to irreversible resistance. Because of the antibacterial properties of zinc oxide nanoparticles, with increasing nanoparticles loading, the resistance of irreversible part compared to the reversible resistance experienced a significant decrease. This confirm that the fabricated nanocomposite membranes did not show affinity toward adsorption of the sludge inside the pores hence substantially limited the membrane fouling. The FTIR results showed the reduction of proteins and polysaccharides onto the surface of the nanoparticle-incorporated membranes, approaching the clean PVC membrane. This was most likely due to the antibacterial properties of ZnO NPs. Nitrogen and phosphor removal for PVC0.5 membrane was 99% and 79% and TSS removal up to 100% was achieved. The findings of this study showed that modification of PVC polymer using ZnO nanoparticles with the presence of ferric chloride coagulant is a very effective technique for municipal wastewater treatment to meet the well-known standard levels.

Roof runoff contamination: Establishing material-pollutant relationships and material benchmarking based on laboratory leaching tests

Because roofs represent a major part of the urban impervious surface, it is hypothesized that roof runoff is an important source of urban stormwater contamination. However, the contribution of different roofing materials to this contamination has only been examined to a limited extent. In this study, a resource and time efficient methodology, which uses some of the principles of a standardized leaching test (CEN/TS16637-2), was developed to identify material-pollutant relationships for sixteen commonly used roofing materials (EPDM, PVC, TPO, EVA, PU and bitumen membranes). Metals were detected in concentrations ranging from several μg/L in the leachate of synthetic materials up to 2.5 mg/L for Zn in the leachate of EPDM materials. Cd and Cr were not detected in any of the leachates. Furthermore, polycyclic aromatic hydrocarbons were detected in most leachates, with phenanthrene and naphthalene being most frequently detected in concentrations up to 4.5 μg/L for naphthalene. Further insights on organic pollutants’ leaching from the tested materials were obtained by a non-target GC-MS screening of the leachates. Several commonly used additives such as flame retardants and light stabilizers were detected. Although no information on long-term leaching and material behavior under outdoor conditions could be obtained by the developed methodology, the laboratory test results could be used to benchmark the materials for their potential impact on roof runoff quality by the calculation of material indexes (which summarize the material-pollutant relationships). EPDM and PU roofing materials were identified as the materials having the highest potential to affect roof runoff quality.

Preparation of Cu3(BTC)2/PVC mixed matrix membrane for pomegranate seed storage

AbstractReducing respiratory intensity of fruits can effectively prolong their postharvest storage time. In this work, Cu3(BTC)2/PVC mixed matrix membrane (MMM) have been synthesized via a facile method and used for pomegranate seeds storage. Structural and properties of the Cu3(BTC)2/PVC MMM were investigated. Results revealed that Cu3(BTC)2/PVC MMM exhibit enhanced moisture permeability, hydrophilicity, and CO2 permeability relative to the PVC membrane. Meanwhile, CO2/O2 selection coefficient of Cu3(BTC)2/PVC MMM was higher than PVC membrane because that CO2 permeability was improved. Based on these results, weight loss of pomegranate seeds packed with Cu3(BTC)2/PVC MMM was reduced by inhibiting respiratory intensity. Meanwhile, Cu3(BTC)2/PVC MMM hindered the decline of total phenol content and nutrient content. We believe that our strategy demonstrate here paves the way to the design and synthesis of novel MMM for the preservation of fresh fruits and vegetables.Practical ApplicationsMixed matrix membrane has been recognized widely used in fruits and vegetables preservation. The effect of Cu3(BTC)2/PVC MMM on prolonging the storage time of pomegranate seeds was investigated. The moisture permeability and gas permeability of Cu3(BTC)2/PVC MMM were studied in detail. Cu3(BTC)2/PVC MMMs can effectively reduce respiratory intensity of pomegranate seeds, which helps to prolong the storage time of pomegranate seeds. The information of this study would help in the harvest preservation of pomegranate seeds, in order to make them fresh for a long time.

Gold-modified paper as microfluidic substrates with reduced biofouling in potentiometric ion sensing

Microfluidic sampling media based on paper and its modifications with either gold nanoparticles or sputtered gold were evaluated for potentiometric determination of Na+, K+, and Cl– ions in clinically relevant samples. The measurements were conducted in comparison to other commonly considered microfluidic substrates, i.e. sponge, polyester textile, and polyamide textile. Ion determination was done by using solid-contact ion-selective electrodes based on plasticized PVC membranes for Na+, K+, and Cl– ions and utilizing PEDOT(PSS) or PEDOT(Cl) as the ion-to-electron transducer. The solid-contact ion-selective electrodes and a solid-state reference electrode were placed directly on the substrate into which the sample solution was wicked. Transport of bovine serum albumin (BSA) through the paper substrate was studied by ellipsometry. Modification of the paper substrates by gold nanoparticles (AuNPs) was found to slow down the transport of BSA through the paper, when compared with unmodified paper substrates and when compared with all the other alternative sampling matrices studied. The retention of BSA obtained with AuNP-modified paper substrates significantly improved the accuracy of the potentiometric ion determinations in sweat, saliva, artificial tears, and artificial serum. The potentiometric results were validated by inductively coupled plasma optical emission spectrometry (ICP-OES) and ion chromatography (IC). The study indicates that modification of paper by AuNPs is a feasible approach to reduce biofouling of sensors that are used in the paper-based analysis of clinically relevant samples.

Ni(II)-selective PVC membrane sensor based on 1,2,4-triazole bis Schiff base ionophore: Synthesis, characterization and application for potentiometric titration of Ni2+ ions against EDTA

This study involves the preparation and investigation of a novel and highly selective poly(vinyl chloride)-based membrane of 2-((5-(2-hydroxy-3-methoxybenzylideneamino)-2H-1,2,4-triazol-3-ylimino)methyl)-6-methoxyphenol Schiff base ligand (HMBT), which is a neutral ionophore with sodium tetraphenyl borate (STB) in the form of an excluder and o -nitrophenyloctyl ether ( o -NPOE) in the form of solvent mediators (plasticizing) as a Ni(II)-selective electrode. The observation of optimal performance was done wherein the membrane was shown to have the HMBT–PVC–NPOE-STB composition of 4:32:63:1.It worked effectively across a broad range of concentration (1.0 × 10 −8 to 1.0 × 10 −2 mol L −1 ). Meanwhile, the Nernstian slope was recorded as 29.3 mV per decade of activity between pH 3.0 and 8.0. The response time of this electrode was fast at 11 s which was used for a span of 100 days with sound reproducibility. According to the selectivity coefficients for trivalent, divalent, and monovalent cations, excellent selectivity was indicated for Ni(II) ions across a large number of citations, whereas no interference was caused by anions like PO 4 3− , SO 4 2− and Cl − . The proposed method in this study was applied successfully to determine Ni(II) content in different samples of water, obtaining suitable recoveries. Additionally, the probed sensor is utilized as indicator electrode when considering Ni 2+ ion potentiometric titration against EDTA. In addition, the chelate’s geometry and structure of the complex formed between Ni 2+ ions and HMBT, abbreviated as HMBT-Ni 2 , was evaluated by separating the solid product. Complex structure was confirmed based on alternative analytical and spectral methods to be structured in the bimetallic form with the formula [Ni 2 (HMBT)(H 2 O) 2 Cl 2 ]. The diamagnetic nature of the complex, which was concluded from the room temperature magnetic moment measurement combined with the UV–Vis measurement, suggested the square planar geometry around the Ni centers.

Surface plasmon resonance based fiber optic potassium ion disposable sensing probe for soil testing

Fabrication and characterization of a fiber optic surface plasmon resonance (SPR) based potassium ion (K+) sensor utilizing the coating of dicyclohexeno-18-crown-6 ionophore incorporated in plasticized PVC membrane along with lipophilic pH sensitive dye chromoionophore-I over the silver coated unclad core of the fiber have been carried out. The interaction between ion selective cocktail layer and incoming K+ changes the effective refractive index of the sensing layer which affects the resonance wavelength in the SPR spectrum. To achieve best sensor performance, the thickness of the sensing layer has been optimized. The sensor probe has been found to be irreversible due to the very strong interaction between ionophore and target K+. The ring type structure of ionophore used provides a close fit to the incoming K+ and hence interacts strongly with it which makes K+ incapable of leaving the cavity of the ionophore. The washing of sensor probe with DI water could not break this bonding. This results in one time use of the probe or disposable type sensor probe. However, the probe works for 0 to 180 µg/mL concentration range of K+. The sensor is highly selective to K+ and is not affected by nitrate, phosphate, calcium and sodium ions and can be used to check the concentration of K+ in soil. In addition, the sensor possesses a response time of around 50 sec. Since the probe has been fabricated on optical fiber it has various advantages such as miniaturization, low cost, fast response, capability of real time monitoring and remote sensing.

Polyvinyl Chloride Modified Carbon Paste Electrodes for Sensitive Determination of Levofloxacin Drug in Serum, Urine, and Pharmaceutical Formulations.

Levofloxacin (LF) is a medically important antibiotic drug that is used to treat a variety of bacterial infections. In this study, three highly sensitive and selective carbon paste electrodes (CPEs) were fabricated for potentiometric determination of the LF drug: (i) CPEs filled with carbon paste (referred to as CPE); (ii) CPE coated (drop-casted) with ion-selective PVC membrane (referred to as C-CPE); (iii) CPE filled with carbon paste modified with a plasticizer (PVC/cyclohexanone) (referenced as P-CPE). The CPE was formulated from graphite (Gr, 44.0%) and reduced graphene oxide (rGO, 3.0%) as the carbon source, tricresyl phosphate (TCP, 47.0%) as the plasticizer; sodium tetrakis[3,5-bis(trifluoromethyl)phenyl] borate (St-TFPMB, 1.0%) as the ion exchanger; and levofloxacinium-tetraphenylborate (LF-TPB, 5.0%) as the lipophilic ion pair. It showed a sub-Nernstian slope of 49.3 mV decade−1 within the LF concentration range 1.0 × 10−2 M to 1.0 × 10−5 M, with a detection limit of 1.0 × 10−5 M. The PVC coated electrode (C-CPE) showed improved sensitivity (in terms of slope, equal to 50.2 mV decade−1) compared to CPEs. After the incorporation of PVC paste on the modified CPE (P-CPE), the sensitivity increased at 53.5 mV decade−1, indicating such improvement. The selectivity coefficient () against different interfering species (Na+, K+, NH4+, Ca2+, Al3+, Fe3+, Glycine, Glucose, Maltose, Lactose) were significantly improved by one to three orders of magnitudes in the case of C-CPE and P-CPE, compared to CPEs. The modification with the PVC membrane coating significantly improved the response time and solubility of the LF-TPB within the electrode matrix and increased the lifetime. The constructed sensors were successfully applied for LF determination in pharmaceutical preparation (Levoxin® 500 mg), spiked urine, and serum samples with high accuracy and precision.

Development of a microplate-format direct optode sensor for ultra-high-throughput environmental and wastewater monitoring of Pb2+

Although many Pb2+-selective optodes have been developed so far, methods using optical sensor membranes have not become widespread in environmental analytical practice. In order to create a bulk optode sensor, which can overcome all of the main drawbacks in the application of conventional optode membranes, - i.e., pH-dependence, long response time and the leakage of the ionic components - unusually thick PVC membrane was developed, embedded in microtiter plates and operated on a novel concept. This is the first reported work, which applies a plate-format optode as well as a direct optode-type sensing membrane for determination of Pb2+. We reported here also the first example for the application of an ionic component-free bulk optode membrane to avoid the membrane leakage, improve the regenerability and extend the lifetime of the membrane. The reported sensor has a LOD above 4.0 × 10−7 M (∼83 μg L−1), thus it is unsuitable for the effective monitoring of drinking waters, but considered to be a promising method for monitoring contamination episodes. On the other hand, the widest pH-independent working range of 4.3 < pH < 7.0 among bulk optodes reported in the literature was realized and an unprecedentedly fast response time of <10 s was achieved. The effectiveness of the applied method was investigated by measuring Pb2+-spiked multicomponent aqueous solutions as simulated environmental or wastewater samples containing near equimolar amounts of Ag+, Ca2+, Co2+, Cu2+, K+, Mg2+, Na+ and Zn2+ as acetate salts. In the presence of these potential competing ions with a concentration not greater than the typical ionic strength of surface freshwaters (∼10−3 M) the reported sensor proved to be appropriate for the selective detection of Pb2+ without any preparation of the samples (e.g., preconcentration, buffering, addition of excipients, etc.) with a required sample volume of only 100 μL. An outstanding analytical performance could be achieved within an average time of less, than 5 s/sample. The reported fluorescent probe is considered to be a promising method for replacing atomic absorption spectroscopy- (AAS), anodic stripping voltammetry- (ASV) or inductively coupled plasma- (ICP) based techniques as well as conventional ion-selective bulk membranes in high-throughput preliminary environmental monitoring of Pb2+, as it provides a cheap and unprecedentedly fast qualitative analysis of contaminated surface and wastewaters.

Design and Characterization of Electrochemical Sensor for the Determination of Mercury(II) Ion in Real Samples Based upon a New Schiff Base Derivative as an Ionophore.

The present paper provides a description of the design, characterization, and use of a Hg2+ selective electrode (Hg2+–SE) for the determination of Hg2+ at ultra-traces levels in a variety of real samples. The ionophore in the proposed electrode is a new Schiff base, namely 4-bromo-2-[(4-methoxyphenylimino)methyl]phenol (BMPMP). All factors affecting electrode response including polymeric membrane composition, concentration of internal solution, pH sample solution, and response time were optimized. The optimum response of our electrode was obtained with the following polymeric membrane composition (% w/w): PVC, 32; o-NPOE, 64.5; BMPMP, 2 and NaTPB, 1.5. The potentiometric response of Hg2+–SE towards Hg2+ ion was linear in the wide range of concentrations (9.33 × 10–8−3.98 × 10–3 molL–1), while, the limit of detection of the proposed electrode was 3.98 × 10–8 molL–1 (8.00 μg L–1). The Hg2+–SE responds quickly to Hg2+ ions as the response time of less than 10 s. On the other hand, the slope value obtained for the developed electrode was 29.74 ± 0.1 mV/decade in the pH range of 2.0−9.0 in good agreement with the Nernstian response (29.50 mV/decade). The Hg2+–SE has relatively less interference with other metal ions. The Hg2+–SE was used as an indicator electrode in potentiometric titrations to estimate Hg2+ ions in waters, compact fluorescent lamp, and dental amalgam alloy and the accuracy of the developed electrode was compared with ICP–OES measurement values. Moreover, the new Schiff base (BMPMP) was synthesized and characterized using ATR–FTIR, elemental analysis, 1H NMR, and 13C NMR. The PVC membranes containing BMPMP as an ionophore unloaded and loaded with Hg(II) are reported by scanning electron microscope images (SEM) along with energy-dispersive X-ray spectroscopy (EDX) spectra.

Potentiometric Sensor for Naproxen Determination

Anaproxen-sensitive potentiometric sensor with a plasticized PVC membrane was designed. The sensor contains an ion associate of naproxen with rhodamine 6G dye and exhibits a linear response to naproxen anion in the range from 8 × 10–5 to 1 × 10–1 M with an electrode function slope characteristic of singly charged ions. The minimum determined concentration is 4 × 10–5 M. This sensor can be used for the detection and determination of naproxen in drugs.

Water purification performance enhancement of PVC ultrafiltration membrane modified with tourmaline particles

Abstract In this study, a novel PVC/tourmaline ultrafiltration membrane was fabricated by phase inversion method in order to improve anti-fouling performance and water quality. FESEM was used to examine the changes in the morphology of pure PVC and PVC/tourmaline hybrid membranes. The introduction of tourmaline resulted in the increase of porosity and mean pore size. EDX images indicated that tourmaline particles were homogeneously dispersed in the membranes when the amount were less than 1.0 wt%. The hybrid membranes exhibited lower contact angle (78.7°) and higher water flux (121.3 L/m2 h) than the pure PVC membrane. The anti-fouling performance of the membranes were studied by filtration of BSA solution. The results demonstrated that the hybrid membrane with 1.0 wt% tourmaline particles exhibited the best anti-fouling performance and the highest BSA rejection. In addition, the pH and conductivity of the filtered water were measured by pH meter and electrical conductivity meter. And the results showed that the quality of the filtered water was improved after treating through the hybrid membranes.

Development of ion-selective electrodes for antipyrine and its derivatives as potential tool for environmental water monitoring

In this work, a set of ion-selective electrodes for the detection of antipyrine and some of its structurally closely related derivatives is developed. These novel potentiometric sensors rely on metallocarborane, cobalt bis(dicarbollide) anion ([3,3′-Co(1,2-C2B9H11)2]−) complexes with the protonated antipyrine derivative as active recognition element. All complexes were characterized, embedded in a PVC membrane, and coated on top of commercial and self-fabricated electrodes. All systems were in-depth evaluated and optimized with focus on their analytical performance, leading to a set of electrodes for antipyrine, 4-aminoantipyrine and 4-(acetamido)antipyrine, which showed a near Nernstian slope (55–57 mV/dec) in the range of 10−5 to 10−2 mol/L and a limit of detection in the μM range. To lower the detection limit and to enable environmental stream water pollution monitoring, we implemented a solid-phase extraction step which could be used to achieve a pre-concentration of a factor >300 (recovery rates: 81–84%) and to lower the detection limit from the μM to the nM range. The combination of our new and highly selective electrodes with this SPE step enables the possibility to monitor antipyrine derivatives simultaneously in either an environmental surrounding or in pharmaceutical formulations. The combination of metallocarborane based ISEs with an SPE pre-concentration step and the in-depth evaluation of the closely related derivatives finally provides a set of valuable tools as well as new insights into their selectivity and real-life applicability.

Lipophilic Fluorescent Dye Liquids: Förster Resonance Energy Transfer-Based Fluorescence Amplification for Ion Selective Optical Sensors Based on a Solvent Polymeric Membrane.

Optical sensors based on solvent polymeric membranes have the potential to measure analytes present in an aqueous solution through the development of a tailored method for a specific target. However, limits in the concentrations of the component dyes have prevented improvements in sensitivity. We propose a Förster resonance energy transfer (FRET)-based fluorescence amplification system for ion-selective optical sensors using a highly fluorescent liquid material composed of a lipophilic phosphonium cation and a pyrene modifying sulfonate anion ([P66614][HP-SO3]), as both the plasticizer and donor, in addition to a combination of the lipophilic phosphonium cation and the fluorescein dodecyl ester anion ([P66614][12-FL]) as the fluorescent sensing dye acceptor. For ion extraction-based sensing, the donor and acceptor were retained in the plasticized PVC membrane with negligible leaching upon exposure to acidic and basic aqueous solutions. Systematic investigation of the donor and acceptor ratios clarified the effect of the amplification factor and the sensitivity of the sensor. At an acceptor doping level of 0.5 mol % (vs donor), an approximately 22-fold higher sensitivity was obtained compared to that of a conventional PVC membrane optical sensor. During ion measurement based on the coextraction of protons and anions, selectivity following the Hofmeister order was observed, which was controlled by the addition of ionophores. The proposed FRET system based on a lipophilic fluorescent liquid material has the potential to significantly improve the sensitivities of optical sensors using solvent polymeric membranes with high selectivities for various target analytes.

Inexpensive ion-selective electrodes for the simultaneous monitoring of potassium and nitrate concentrations in nutrient solutions.

A fast, simple and inexpensive potentiometric method has been developed for the determination of the major ions potassium and nitrate in nutrient solutions, by means of ion-selective electrodes (ISEs) based on plasticized polyvinyl membranes containing an ion-exchanger. Tridodecylmethylammonium chloride (TDMACl) and potassium tetrakis(4-chlorophenyl)borate (KTClPB) were used as ion-exchangers for the nitrate and potassium electrodes, respectively. Electrode membranes built with different plasticizers, bis-[2-ethylhexyl]-sebacate (DOS), tricresyl phosphate (TCP) and 2-nitrophenyloctyl ether (NPOE), were tested, and NPOE was selected. The electrodes were calibrated over both wide and narrow concentration ranges and residual analysis was made. Based on the results of these calibrations, the method of standard addition was developed and found to be suitable for the simultaneous determination of potassium and nitrate in nutrient solutions. A large group of samples taken from different stages of hydroponic crops was analysed. Several approaches recommended for statistical comparisons of the results obtained by potentiometric and by reference methods were tested, obtaining satisfactory results. The potentiometric methodology developed is promising for monitoring the concentration of these essential nutrients in nutrient solutions.

Development of PVC membrane potentiometric sensor for the determination of potassium ion and its applications

Development of PVC membrane potentiometric sensor for the determination of potassium ion and its applications

Analysis of the Causes of PVC Membrane Defects that Caused Soft Roof Leaks

Analysis of the Causes of PVC Membrane Defects that Caused Soft Roof Leaks

Oil-in-water emulsion separation by PVC membranes embedded with GO-ZnO nanoparticles

Membrane technology is regarded as the most promising approach for oily wastewater treatment. In this study, GO and GO-ZnO nanoparticles were incorporated into PVC membranes to enhance antifouling properties in oily wastewater treatment. The results of FTIR analysis revealed that ZnO nanoparticles were successfully anchored on GO nanosheets. In addition, XRD results indicated that the presence of ZnO increased the distance between GO nanosheets. Fabricated membranes were characterized via contact angle, tensile testing, pure water flux, field emission scanning electron microscope (FESEM) and atomic force microscopy (AFM). FESEM results illustrated that modification of GO with ZnO reduced its agglomeration in the membrane matrix. The reduction of contact angle from 80° for pure PVC membrane to 67° for 0.1% GO-ZnO containing membrane showed that the hydrophilicity of the membranes was enhanced by increasing nanoparticles content. The same trend was observed for water flux of PVC/GO and PVC/GO-ZnO nanocomposite membranes indicating that membranes with 0.05 wt% of both GO and GO-ZnO exhibited the highest pure water flux. The presence of nano additives also increased the mechanical strength of the membranes due to the synergistic property of the nano additives. Finally, the membranes were evaluated in a lab scale cross flow system with synthetic oily wastewater as feed. The results showed that PVC/GO-ZnO membranes had lower flux reduction and higher turbidity removal efficiency than neat PVC and PVC/GO membranes.

Comparative study of embedded functionalised MWCNTs and GO in Ultrafiltration (UF) PVC membrane: interaction mechanisms and performance

ABSTRACT This work presents the development of polyvinyl chloride/functionalised multi-carbon nanotube (PVC/F-MWCNT) membranes and PVC/graphene oxide (PVC/GO) membranes for the improved removal of chemical oxygen demand (COD) from actual petroleum wastewater. Also, this work for the first time presents the proposed interaction mechanism between the contents of PVC/GO and PVC/F-MWCNT membranes as well as the interaction mechanism of each composite membrane with water molecules. The effect of both F-MWCNT and GO content on the characteristics and performance of the PVC/F-MWCNT membrane and PVC/GO membrane were studied. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscopy (AFM), contact angle (CA), differential scanning calorimetry (DSC), porosity and tensile strength were used to examine the properties of F-MWCNT, GO, PVC/F-MWCNT and PVC/GO membranes. The composite membranes’ performance was studied by measuring the rejection of chemical oxygen demand (COD) and mass flux. It was found that F-MWCNTs and GO played significant roles in the membranes’ structural morphology. A significant improvement was obtained in the CA, porosity and tensile strength of the membranes by embedding the PVC casting solution with 0.12 wt% of each F-MWCNTand GO. The PVC/F-MWCNTs membrane showed higher performance in term of mass flux and COD rejection that reached 88.9%, which makes using a PVC/F-MWCNTs membrane preferable to remove COD from petroleum wastewater.