Synthesis, characterization, permeation and antibacterial properties of cellulose acetate/polyethylene glycol membranes modified with chitosan (original) (raw)
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Preparation and Characterization of Antibacterial Cellulose/Chitosan Nanofiltration Membranes
Polymers, 2017
Presently, most nanofiltration membranes are prepared with non-biodegradable petrochemical materials. This process is harmful to the ecosystem and consumes a large amount of non-renewable energy. In this study, biodegradable and biocompatible antibacterial cellulose/chitosan nanofiltration membranes (BC/CS-NFMs) were fabricated and characterized for their mechanical strength, antimicrobial activity, salt and dye filtration performance, and polyethylene glycol (PEG) retention using Thermal gravimetric analysis (TGA), Field emission scanning electron microscopy(FE-SEM), Fourier transform infrared spectroscopy(FT-IR), and X-ray diffraction (XRD). The BC/CS-NFMs were obtained by the hydrolysis and carboxymethylation of dense cellulose/chitosan membranes (BC/CSMs). The tensile strength of the BC/CS-NFMs decreased as the chitosan content increased. In addition, the thermal stability and antibacterial ability of the BC/CS-NFMs improved. The pore size is less than 1 nm, and a spongy, layered structure is observed in the cross-sectional FE-SEM images. FT-IR analysis shows that a part of the hydroxyl in cellulose transforms to carboxymethyl during the hydrolysis and carboxymethylation of the BC/CSMs. No obvious changes can be observed in the cellulose and chitosan after the blend membrane formation from the XRD measurements. Based on the experimental results on the permeation and rejection of BC/CS-NFMs, different proportions of cellulose and chitosan nanofiltration membranes almost did not affect the water flux and rejection rate. The BC/CS-NFMs showed better water flux and a higher rejection rate in aqueous dye-salt solutions.
International Journal of Molecular Sciences, 2021
Chitosan and polyethylene glycol (PEG-600) membranes were synthesized and crosslinked with 3-aminopropyltriethoxysilane (APTES). The main purpose of this research work is to synthesize RO membranes which can be used to provide desalinated water for drinking, industrial and agricultural purposes. Hydrogen bonding between chitosan and PEG was confirmed by displacement of the hydroxyl absorption peak at 3237 cm−1 in pure chitosan to lower values in crosslinked membranes by using FTIR. Dynamic mechanical analysis revealed that PEG lowers Tg of the modified membranes vs. pure chitosan from 128.5 °C in control to 120 °C in CS-PEG5. SEM results highlighted porous and anisotropic structure of crosslinked membranes. As the amount of PEG was increased, hydrophilicity of membranes was increased and water absorption increased up to a maximum of 67.34%. Permeation data showed that flux and salt rejection value of the modified membranes was increased up to a maximum of 80% and 40.4%, respectively...
Journal of Applied Polymer Science, 2019
Solution casting method was used to synthesize chitosan (CS)-based membranes for reverse osmosis (RO) using PEG-300 and tetraethylorthosilicate as a crosslinker. Their salt rejection (%) and permeate flux (mL/h.m 2) was measured by using lab scale RO plant. FTIR spectroscopy reveals interactions between CS and PEG by shifting of OH peak from 3237 cm −1 to lower wavenumber in modified membranes. SEM results showed pores in modified membranes while pure CS membranes had uniform nonporous and dense microstructure. DMA results demonstrated that the addition of PEG lowers the T g value up to 6.5%. Water content of membranes increases up to 82.63% as the amount of PEG increases owing to its hydrophilic nature. The bacterial killing ability showed that the modified membranes possess good antibacterial activity against Escherichia coli in comparison to the control film. The permeation results revealed that salt rejection and flux of the modified membranes increased up 60% and 86.36 mL/h.m 2 , respectively.
JOURNAL OF ADVANCES IN PHYSICS, 2018
Chitosan (Ch) and Cellulose Acetate (CA) natural polymer in addition to other samples with different mass fractions of Chitosan/Cellulose Acetate (Ch/CA) were synthesized via simple casting route. Prepared samples were studied using FT-IR and UV/vis spectroscopic techniques. Structural variations due to the process of blending were retraced using X-ray diffraction data (XRD) and morphological investigation using scanning electron microscopy (SEM). Obtained spectral data reveals compatibility and complexation between polymer constituents identified through presence of polymer characteristic peaks with small variation in both intensity and position along with change in the value of optical energy gap from UV optical absorption spectral data. XRD pattern indicate the semicrystalline nature of the studied sample with an observable change in the crystallinity. Moreover, scanning electron microscopic (SEM) micrographs reveals homogenous structure without any evidence for agglomerations ne...
In this work, a series of cellulose acetate/polyethylene glycol-600 membranes, with varying ratios were prepared by 2-stage phase inversion protocol. The permeation properties were studied by subjecting membranes in indigenously fabricated reverse osmosis plant. After optimization of different CA/PEG ratios, themembranewith highest salt rejection capacity was selected and modified with varying amount of silica. The Modified membranes were characterized for their permeation properties, hydrophilicity, compositional analysis, thermal stability,mechanical strength and morphological studies. Silica significantly influenced the permeation performance of composite membrane. The flux enhanced from 0.35 to 2.46 L/h m2 along with an 11.41% relative increase in salt rejection. The hydrophilicity was significantly enhanced by the addition of silica. In FTIR spectra, the broadening of the peak around 3500 cm−1 and emergence of peak at 950 cm−1 specified the incorporation of silica particles. The thermal analysis indicated the relative increase in degradation temperature (Tmax) and glass transition temperature (Tg) for CPS-5 membrane. The mechanical stability of the modified membranes, increased initially, but declined with further addition of silica. The results indicated that the incorporation of SiO2 content in the casting solution improved the fouling resistance of the membranes.
Journal of Taibah University for Science
In this research, the membranes were stemmed from the biopolymer containing quaternary amine moieties (Chitosan and Chitosan-palm) for nanofiltration purposes. The developed membranes were fully featured using different characterization techniques (SEM), (TGA), zeta potential, and contact angle measurement. The membrane's features were systematically characterized in hydrophilicity contact angle, surface morphology, and charge on the surface, acidity, and water permeability. The permeability of water for the chitosan membrane with palm was 3.04 ± 0.12 L m −2 h −1 bar −1 twice as the average permeability of the pristine chitosan membrane 1.68 ± 0.04 L m −2 .h −1 .bar −1. The salt rejection was enhanced (from 5% for NaCl to 70% for MgCl 2 in the same condition). These membranes could endure up to 22 bar. Therefore, the developed Chitosan and chitosan-palm membranes are more noteworthy for water treatment than the other commercially available membranes and costly activated carbons.
Journal of the Taiwan Institute of Chemical Engineers, 2015
In order to tap the seemingly boundless problem of water scarcity, reverse osmosis (RO), has been formulated as a significant solution. However, RO technology, suffers by a major challenge of biofouling, which results in reduced production capacity and increased operation costs. Thus, there is an urgent demand to fabricate an appropriate disinfection membrane surface with maximum permeation performance. In this work, cellulose acetate/poly ethylene glycol membranes impregnated with silver particles were prepared by 2-stage phase inversion protocol. The Modified membranes were characterized for their compositional analysis, surface roughness, surface morphology, permeation properties, membrane hydraulic resistance and antibacterial activity. The presence of functional group was determined by FTIR spectra. The asymmetric surface morphology of membranes was elucidated from the scanning electron microscope. The varying nature of nodules and interstices spaces was observed in the images obtained by the atomic forced microscopy. The progressive decreased was observed in the surface roughness of membranes. The modification has significantly increased the flux and salt rejection capacity of membranes. All modified membranes exhibited remarkable antibacterial properties against gram negative Escherichia Coli. The synthesis of cellulose acetate membrane, doped with polyethylene glycol and modified with silver, provides a convenient way for the development of selfsterilized membranes. of non-conventional water sources, such as seawater or ocean water is of considerable interest due to the usual immediate proximity of such water sources for areas that are highly water-stressed [7]. Desalination of sea or saline water has been practiced regularly for over 50 years and is a well-established means of water supply in many countries . Two main directions have evolved the desalination technology, namely evaporation and membrane techniques. Among various membrane processes, reverse osmosis (RO) is the most prevalent processes as it offers multiple advantages such as low energy consumption, environmental friendliness, simplicity, elevated recovery rate and high salt rejection [9,10].
MATEC Web of Conferences
Produced water is a wastewater generated from petroleum industry with high concentration of pollutants such as Total Dissolved Solid, Organic content, and Oil and grease. Membrane technology has been currently applied for produced water treatment due to its efficiency, compact, mild and clean process. The main problem of produced water using membrane is fouling on the membrane surface which causes on low permeate productivity. This paper is majority focused on the improvement of anti-fouling performance through several modifications to increase CA membrane hydrophilicity. The membrane was prepared by formulating the dope solution consists of 18 wt-% CA polymer, acetone, and PEG additive (3 wt-%, 5 wt-%, and 7 wt-%). The membranes are casted using NIPS method and being irradiated under UV light exposure. The SEM images show that parepared membrane has asymmetric structure consist of dense layer, intermediete layer, and finger-like support layer. The filtration test shows that PEG addition increase the membrane hydrophilicity and the permeate flux increases. UV light exposure on the membrane improves the membrane stability and hydrophilicity. The imrpovement of membrane anti-fouling performance is essential to achieve the higher productivity without lowering its pollutants rejection.
Preparation of cellulose triacetate/cellulose acetate (CTA/CA)-based membranes for forward osmosis
Journal of Membrane Science, 2013
Cellulose triacetate/cellulose acetate (CTA/CA)-based membranes for forward osmosis (FO) were prepared by immersion precipitation. Casting composition and preparation conditions-1,4-dioxane/ acetone ratio, CTA/CA ratio, substrate type, casting thickness, evaporation time and annealing temperaturewere tested for their effects on formation and subsequent performance of membranes. Membranes were characterized by various methods, and their performances were tested against commercially available membranes. The FO membrane prepared under optimized composition and conditions had a smooth surface and showed higher water flux and salt resistance than the commercial membranes. Annealing improved the membrane performance by removing residual additives and solvents. The computerized image processing of optical microscopy images was shown to be useful for assessing the membrane substrates.