Composite Membranes of Cellulose Acetate and Zirconium Dioxide: Preparation and Study of Physicochemical Characteristics (original) (raw)
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The casting and preparation of ultrafiltration ZnO modified cellulose acetate membrane (CA/ZnO) were investigated in this work. CA membranes were fabricated by phase inversion using dimethylformamide (DMF) as a solvent and ZnO as nanostructures materials. Ultrafiltration (UF) performance, mechanical stability, morphology, contact angle, and porosity were evaluated on both CA- and ZnO-modified CA samples. Scanning electron microscopy (SEM) was used to determine the morphology of the membranes, showing different pore sizes either on rough surfaces and cross-sections of the samples, an asymmetric structure and ultra-scale pores with an average pore radius 0.0261 to 0.045 µm. Contact angle measurements showed the highest hydrophobicity values for the samples with no ZnO addition, ranging between 48° and 82.7° on their airside. The permeability values decreased with the increasing CA concentration in the casting solution, as expected; however, ZnO-modified membranes produced lower flux t...
Improvement of cellulose acetate forward osmosis membrane performance using zinc oxide nanoparticles
DESALINATION AND WATER TREATMENT
With the continual progress in developing the forward osmosis (FO) membrane, in both industry and academia, it is prospected to remain the best alternative technique for the production of freshwater. The current paper focuses on the preparation and characterization of FO membranes and ZnO nanoparticles (ZnO NPs) that can be used for membrane modification to enhance its performance. FO membranes are fabricated in our labs from the cellulose acetate (CA) polymer by phase inversion methods. These membranes are easy to prepare, stable against bacterial attack, chemical, and mechanical changes, as well as showing excellent performance and superior economics. The optimum conditions for preparing forward osmosis cellulose acetate (FO-CA) membranes are; 7 wt.% CA, 92.75 wt.% acetone, and 0.25 wt.% ZnO NPs per unit percentage of CA in aqueous solution. A new approach for the modification of CA membranes using the synthesized ZnO NPs was shown to enhance the performance of membranes for forward osmosis water desalination process. We study the effect of polymer concentration, membrane thickness, and membrane modification by ZnO NPs on membrane performance. The fabricated membranes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy, and the mechanical properties were studied in order to expose the best membrane for water desalination and also the synthesized ZnO NPs were characterized by XRD and SEM. The performance of the CA/ZnO NPs membranes were examined using parameters, such as contact angle, surface area and pore size, water flux (J w), and salt rejection (R%). Compared with the pure CA membrane, the CA membrane modified with ZnO NPs was more hydrophilic, with an improved water contact angle (~47.6 ± 2°) over the pure CA membrane (~63.85 ± 2°) and it showed improving in water flux (26.57 L h −1 m −2) over the pure CA membrane (19.42 L h −1 m −2), also it showed salt rejection 99.5% of Na + , 100% of Cl-, and 99.6% of Mg 2+. The water flux increased in the case of CA membrane modified with ZnO NPs is due to increasing in surface area and total pore volume than the pure CA membrane by 23% and 20%, respectively. This demonstrates that the CA membrane modified with ZnO NPs can significantly improve the membrane performances and was suitable to enhance the selectivity, and water flux of the membranes for water desalination.
Preparation and characterization of cellulose acetate propionate membrane
International Journal of Advances in Applied Sciences (IJAAS), 2024
Membrane technology is a technique in water and wastewater treatment that has many advantages. This study focuses on the manufacture and characterization of cellulose acetate propionate (CAP) membranes using the phase inversion method. The CAP is preferable since it is a biopolymer that is environmentally friendly and cheap. The production of CAP membrane was carried out using phase inversion method, and varied in 3 different concentrations of CAP i.e., 13, 14, and 15% wt., with additional material of polyethylene glycol (PEG). The characterization was conducted using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) analysis to determine its morphology, pores, and functional groups. The results show that the membrane containing 13% wt. CAP exhibits higher porosity with more macropores than a membrane with 14 and 15% wt. CAP. However, membranes with higher concentrations of CAP show more uniform pores and fewer macropores. FTIR analysis confirmed the presence of functional groups in the membrane such as C-O, -CH3, C=O, C-H, and OH. It is also found that there is a shift in Wavenumber due to the increase in the concentration of CAP in each membrane.
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The main objective of this work has been to study the performance of membranes developed for water treatment. Polymeric membranes (CTP and CTP-Acid) were developed from solutions containing cellulose acetate (CA), cellulose triacetate (CTA) and polysulfone (PSF), using maleic acid (MA) and acetic acid (AA) as additives and chloroform/dioxane as solvent. The NIPS-type phase inversion method was chosen as the membrane film manufacturing technique. The incorporation of 2.5% and 5% by weight of acids in the membrane mixture allowed us to study the additive effect on the morphological structure, and to predict the performance of the membranes formed. The characterization of the membranes was performed by SEM and FTIR analyses. Examining the flux, permeability and selectivity of the membranes also permitted to study the efficiency and performance of each membrane. The addition of AA and MA additives within the mixture increased the hydrophilic character and improved the flux rate by incre...
Polycarbonate Urethane-Hydroxypropyl Cellulose Membranes with Zinc Oxide Nanoparticles
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Polycarbonate urethane-hydroxypropyl cellulose (PCU-HPC) membranes were synthesized and the impact of adding progressive amounts of zinc oxide nanoparticles (ZnONPs) on the morphological, thermal, mechanical, wetting and antibacterial properties of the membranes was investigated. Materials characterization was performed by Fourier transform infrared spectroscopy (FTIR), environmental scanning electron microscopy (ESEM), thermogravimetric analysis (TGA), dynamic vapour sorption (DVS), contact angle (CA) and mechanical testing. Results showed that Young’s modulus and tensile strength increased, while elongation at break decreased. All membranes presented good antibacterial activity against Escherichia coli.
Cellulose Chemistry and Technology, 2020
Cellulose has lately gained much attention in its use as membrane due to the fact that it is cheap and has the potential to remove dissolved ions and organic contaminants. This is despite the fact that cellulose suffers from lack of reactive functional groups, as well as poor thermal and chemical resistance. The incorporation of silica (SiO 2) into cellulose membranes offers design flexibility, permeation performance, durability improvement, thermal stability and enhances its surface hydrophilicity. Cellulose membranes further exhibit improved mechanical performance, when the silica is uniformly dispersed at very low filler concentration. This study aims to review the incorporation of silica in cellulose nanocomposites for potential usage in water filtration membranes. The study further overviews the synthesis and modification of silica nanocomposites using various methods and processes.
Evaluation of cellulose and carboxymethyl cellulose/poly(vinyl alcohol) membranes
Carbohydrate Polymers, 2013
Cellulose was isolated from rice straw and converted to carboxymethyl cellulose (CMC). Both polymers were crosslinked with poly(vinyl alcholo) (PVA). The physical properties of the resulting membranes were characterized by FT-IR, TGA, DSC and SEM. The cellulose and CMC were first prepared from bleached rice straw pulp. The infrared spectroscopy of the resulting polymer membranes indicated a decrease in the absorbance of the OH group at 3300-3400 cm −1 , which is due to bond formation with either the cellulose or CMC with the PVA. The thermal stability of PVA/cellulose and PVA/CMC membranes was lower than PVA membrane. The surface of the resulting polymer membranes showed smooth surface in case of the PVA/CMC membrane and rough surface in case of the PVA/cellulose membrane. Desalination test, using 0.2% NaCl, showed that pure PVA membranes had no effect while membranes containing either cellulose or CMC as filler were able to decrease the content of the NaCl from the solution by 25% and 15%, respectively. Transport properties, including water and chloroform vapor were studied. The moisture transport was reduced by the presence of both cellulose and CMC. Moreover, the membranes containing cellulose and CMC showed significantly reduced flux compared to the pure PVA. The water sorption, solubility and soaking period at different pH solutions were also studied and showed that the presence of both cellulose and CMC influences the properties.
Progress in Rubber Plastics and Recycling Technology, 2012
The present investigation deals with the preparation of a new organic–inorganic hybrid membrane based on cellulose acetate (CA)/tetraethyl orthosilicate (TEOS) by the sol–gel and phase-inversion process. This paper also investigates the effect of TEOS content on the mechanical, thermal, and ultrafiltration (UF) performance of the newly prepared membranes. These newly prepared membranes were characterised by Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis (TGA) and scanning electron microscopy (SEM). The ultrafiltration performance of the membranes was examined by water content (%), compaction, and pure water flux. Results showed that the addition of TEOS increased the thermal and mechanical properties. SEM results showed that the pore size decreased but the number of pores increased on the addition of TEOS. Moreover, the hydrophilicity and permeability increased with increase in TEOS content from 0 to 2 wt%. Thus, it can be concluded that these hybrid membr...
Performance characterization of cellulose acetate and poly(vinylpyrrolidone) blend membranes
Journal of Applied Polymer Science, 2007
Hydrophilic ultrafiltration membranes have been prepared by blending cellulose acetate (CA) as a matrix polymer with increasing concentrations of poly(vinylpyrrolidone) (PVP) using N,N′-dimethylformamide as the solvent. It is observed that the presence of PVP beyond 50 wt % in the casting solution did not form membranes. Prepared membranes have been subjected to ultrafiltration characterizations such as compaction, pure water flux, water content, and membrane hydraulic resistance. The results indicate significant changes in the characteristics upon the addition of PVP, which may lead to improved performance. The porosity, pore size, and molecular weight cut-off of the membranes also increase as the concentration of PVP increases. It is estimated that the pore radius of the CA/PVP membranes increases from 30 to 63 Å, when the concentration of PVP increased from 0 to 50 wt %. This is in agreement with the results obtained from scanning electron microscopic studies. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Influence to the performance of cellulose acetate reverse osmosis membranes by fibers addition
Journal of Applied Polymer Science, 2008
The asymmetric membranes based on cellulose acetate are mainly applied for separations in aqueous systems and in reverse osmosis processes, although they can also be used in the so-called salinity process of energy generation. These applications require membranes with considerable water permeability and high salt rejection. In this paper the improvements resulting from the addition of two different types of fibers on the permeability performance of the membranes (water permeability and salt rejection) as well as on mechanical properties are presented. Concerning the water permeability and salt rejection, the influence of four different contents of cellulosic fibers (CF) and anionic diethylaminoethyl cellulose (DEAE) fibers has been studied and the optimum value was chosen after measuring water permeability and salt rejection of the membranes. To study the mechanical performance, membranes with six different contents of these two types of fibers were produced. Both permeability and mechanical test results obtained for membranes with different contents of fibers were compared with the ones for the membranes produced from the same solution but without fibers. In terms of permeability tests, the membranes with 0.5 wt % CF fibers present the best results, with water permeability 22.8% higher than the membrane without fibers, while the salt rejection only decreases by 7.3%. Concerning the mechanical properties, the best membrane would be the one with 3 wt % CF fibers, however the membrane with 0.5 wt % CF fibers still present a toughness 18.9% higher than the membrane without fibers.