scholarly journals Crown Ether-Immobilized Cellulose Acetate Membranes for the Retention of Gd (III)

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3978
Author(s):  
Oana Steluta Serbanescu ◽  
Andreea Madalina Pandele ◽  
Madalina Oprea ◽  
Augustin Semenescu ◽  
Vijay Kumar Thakur ◽  
...  
Keyword(s):  
Cellulose Acetate ◽  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Separation Efficiency ◽  
Membrane Surface ◽  
Nitrate Solution ◽  
Cellulose Acetate Membrane ◽  
Retention Performance ◽  
Easy Method ◽  
Cellulose Acetate Membranes

This study presents a new, revolutionary, and easy method of separating Gd (III). For this purpose, a cellulose acetate membrane surface was modified in three steps, as follows: firstly, with aminopropyl triethoxysylene; then with glutaraldehyde; and at the end, by immobilization of crown ethers. The obtained membranes were characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), through which the synthesis of membranes with Gd (III) separation properties is demonstrated. In addition, for the Gd (III) separating process, a gadolinium nitrate solution, with applications of moderator poison in nuclear reactors, was used. The membranes retention performance has been demonstrated by inductively coupled plasma mass spectrometry (ICP-MS), showing a separation efficiency of up to 91%, compared with the initial feed solution.

scholarly journals Synthesis and Characterization of Cellulose Acetate Membranes with Self-Indicating Properties by Changing the Membrane Surface Color for Separation of Gd(III)

Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 468 ◽  
Author(s):  
Oana Steluta Serbanescu ◽  
Andreea Madalina Pandele ◽  
Florin Miculescu ◽  
Stefan Ioan Voicu
Keyword(s):  
Cellulose Acetate ◽  
Photoelectron Spectroscopy ◽  
Membrane Surface ◽  
Feed Solution ◽  
Separation Process ◽  
Process Efficiency ◽  
Cellulose Acetate Membrane ◽  
Easy Method ◽  
Gadolinium Nitrate ◽  
Cellulose Acetate Membranes

This study presents a new, revolutionary, and easy method for evaluating the separation process through a membrane that is based on changing the color of the membrane surface during the separation process. For this purpose, a cellulose acetate membrane surface was modified in several steps: initially with amino propyl triethoxysilane, followed by glutaraldehyde reaction and calmagite immobilization. Calmagite was chosen for its dual role as a molecule that will complex and retain Gd(III) and also as an indicator for Gd(III). At the contact with the membrane surface, calmagite will actively complex and retain Gd(III), and it will change the color of the membrane surface during the complexation process, showing that the separation occurred. The synthesized materials were characterized by Fourier transform infrared spectroscopy (FT-IR), thermal analysis (TGA-DTA), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy, demonstrating the synthesis of membrane material with self-indicating properties. In addition, in the separation of the Gd(III) process, in which a solution of gadolinium nitrate was used as a source and as a moderator in nuclear reactors, the membrane changed its color from blue to pink. The membrane performances were tested by Induced Coupled Plasma–Mass Spectrometry (ICP-MS) analyses showing a separation process efficiency of 86% relative to the initial feed solution.

Study on Heparin-Like Surface Based on Nanofibrous Membrane of Cellulose Acetate and its Blood Compatibility

2012 ◽  
Vol 159 ◽  
pp. 317-321 ◽  
Author(s):  
Ping Lan ◽  
Wei Wang ◽  
Jian Da Cao
Keyword(s):  
Cellulose Acetate ◽  
Anticoagulant Activity ◽  
Membrane Surface ◽  
Water Soluble ◽  
Nanofibrous Membrane ◽  
Membrane Properties ◽  
Degree Of Hydrolysis ◽  
Research Approach ◽  
Cellulose Acetate Membrane ◽  
Cellulose Acetate Membranes

Heparin-like anticoagulant materials have been intensively studied over the past several years, many of effective works focus on the preparation of homogeneous sulfonated polymer and further anticoagulation and filtration properties.1 Due to high water-soluble properties of homogeneous materials, its applied scope is limited. In this study, nanofibrous membrane of cellulose acetate is chosen. By controlling degree of hydrolysis on the membrane surface and its further surface sulfonation, heparin-like surface has been built on cellulose derivative membranes where there are plenty of sulfonic acid group. In this paper, some testing means such as surface contact angle, ATR-FTIR, XPS and platelet adhesion are used to characterize membrane properties. The results show that our research approach is feasible, effects of hydrolysis and sulfonation are obvious on cellulose acetate membranes. In the meantime, the surface hydrophilicity of membrane is increased significantly; In addition, patelet adhesion experiments show that platelets adsorption decrease obviously after heparin-like treatment on the cellulose acetate membrane, showing an excellent anticoagulant activity.

Effect of the structure of cellulose acetate membranes on their permeability, electrical conductivity and rejection

1990 ◽  
Vol 55 (12) ◽  
pp. 2933-2939 ◽  
Author(s):  
Hans-Hartmut Schwarz ◽  
Vlastimil Kůdela ◽  
Klaus Richau
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Cellulose Acetate ◽  
Reverse Osmosis ◽  
Water Flux ◽  
Cellulose Acetate Membrane ◽  
Structure Parameters ◽  
Dc Electrical Conductivity ◽  
Cellulose Acetate Membranes

Ultrafiltration cellulose acetate membrane can be transformed by annealing into reverse osmosis membranes (RO type). Annealing brings about changes in structural properties of the membranes, accompanied by changes in their permeability behaviour and electrical properties. Correlations between structure parameters and electrochemical properties are shown for the temperature range 20-90 °C. Relations have been derived which explain the role played by the dc electrical conductivity in the characterization of rejection ability of the membranes in the reverse osmosis, i.e. rRO = (1 + exp (A-B))-1, where exp A and exp B are statistically significant correlation functions of electrical conductivity and salt permeation, or of electrical conductivity and water flux through the membrane, respectively.

scholarly journals Insights on the Influence of Surface Chemistry and Rim Zone Microstructure of 42CrMo4 on the Efficiency of ECM

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2132
Author(s):  
Alexander Schupp ◽  
Oliver Beyss ◽  
Bob Rommes ◽  
Andreas Klink ◽  
Daniela Zander
Keyword(s):  
Mixed Oxide ◽  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Material Removal ◽  
Chemical Elements ◽  
Nitrate Solution ◽  
Electrochemical Machining ◽  
Process Efficiency ◽  
Negative Effect ◽  
Sodium Nitrate Solution

The electrochemical machining (ECM) of 42CrMo4 steel in sodium nitrate solution is mechanistically characterized by transpassive material dissolution and the formation of a Fe3−xO4 mixed oxide at the surface. It is assumed that the efficiency of material removal during ECM depends on the structure and composition of this oxide layer as well as on the microstructure of the material. Therefore, 42CrMo4 in different microstructures (ferritic–pearlitic and martensitic) was subjected to two ECM processes with current densities of about 20 A/cm2 and 34 A/cm2, respectively. The composition of the process electrolyte was analyzed via mass spectrometry with inductively coupled plasma in order to obtain information on the efficiency of material removal and the reaction mechanisms. This was followed by an X-ray photoelectron spectroscopy analysis to detect the chemical composition and the binding states of chemical elements in the oxide formed during ECM. In summary, it has been demonstrated that the efficiency of material removal in both ECM processes is about 5–10% higher for martensitic 42CrMo4 than for ferritic–pearlitic 42CrMo4. This is on one hand attributed to the presence of the cementite phase at ferritic–pearlitic 42CrMo4, which promotes oxygen evolution and therefore has a negative effect on the material removal efficiency. On the other hand, it is assumed that an increasing proportion of Fe2O3 in the mixed oxide leads to an increase in the process efficiency.

Facile fouling resistant surface modification of microfiltration cellulose acetate membranes by using amino acid l-DOPA

2013 ◽  
Vol 68 (4) ◽  
pp. 901-908 ◽  
Author(s):  
Sara Azari ◽  
Linda Zou ◽  
Emile Cornelissen ◽  
Yasushito Mukai
Keyword(s):  
Surface Modification ◽  
Amino Acid ◽  
Cellulose Acetate ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Fouling Resistance ◽  
Widespread Application ◽  
Potential Measurement ◽  
Cellulose Acetate Membranes ◽  
Microfiltration Membranes

A major obstacle in the widespread application of microfiltration membranes in the wet separation processes such as wastewater treatment is the decline of permeates flux as a result of fouling. This study reports on the surface modification of cellulose acetate (CA) microfiltration membrane with amino acid l-3,4-dihydroxy-phenylalanine (l-DOPA) to improve fouling resistance of the membrane. The membrane surface was characterised using Fourier transform infrared spectroscopy (FTIR), water contact angle and zeta potential measurement. Porosity measurement showed a slight decrease in membrane porosity due to coating. Static adsorption experiments revealed an improved resistance of the modified membranes towards the adhesion of bovine serum albumin (BSA) as the model foulant. Dead end membrane filtration tests exhibited that the fouling resistance of the modified membranes was improved. However, the effect of the modification depended on the foulant solution concentration. It is concluded that l-DOPA modification is a convenient and non-destructive approach to enable low-BSA adhesion surface modification of CA microfiltration membranes. Nevertheless, the extent of fouling resistance improvement depends on the foulant concentration.

scholarly journals Fabrication and Characterization of Nano Hybrid Cellulose Acetate-nanoTiO2/crosslinked Polyvinyl Alcohol Coated Membrane for Crude Clove Oil Purification

2019 ◽  
Vol 64 (3) ◽  
pp. 304-319
Author(s):  
Tutuk Djoko Kusworo ◽  
Widayat Widayat ◽  
Dani Puji Utomo
Keyword(s):  
Polyvinyl Alcohol ◽  
Cellulose Acetate ◽  
Membrane Surface ◽  
Polymer Concentration ◽  
Nano Particles ◽  
Inversion Method ◽  
Cellulose Acetate Membrane ◽  
Clove Oil ◽  
Oil Purification ◽  
Coated Membrane

The application of membranes for clove oil purification has the potential to improve the efficiency and effectiveness of processing. The main problem that occurs is the polymer-based membranes tend to change in properties such as weakening, dissolving, and swelling when contact with clove oil. In this study, cellulose acetate membrane was developed with TiO2 nano-particles to reduce swelling effect and coating with polyvinyl alcohol (PVA) to modify membrane surface. The membranes were prepared using dry-wet phase inversion method from dope solution with polymer concentration of 14–20 wt% and nano-particles of TiO2 with a concentration of 0–1.5 wt% in total solid. The formed membrane was coated with PVA with a concentration of 2–5 wt% crosslinked using glutaraldehyde. The SEM results show that prepared membrane are asymmetric membranes and show the coated layer of PVA on the surface. The FTIR spectra confirm that the PVA is successfully crosslinked and the addition of nano-particles TiO2 decreases the membrane swelling degree, significantly. In the addition of 0.5 wt% of nano-TiO2 can increase the flux from 0.54 to 0.66 L × m−2 × h−1 × bar−1. The coated membrane surface using PVA increases the selectivity of the membrane to produce clove oil permeates with eugenol content of 82.5 % from 68 %.

scholarly journals Pengolahan Air Limbah Menjadi Air Minum Dengan Menghilangkan Amonium Dan Bakteri E-Coli Melalui Membran Nanofiltrasi

2018 ◽  
Vol 1 (1) ◽  
pp. 6
Author(s):  
Malikhatul Hidayah
Keyword(s):  
Waste Water ◽  
Wastewater Treatment ◽  
Water Treatment ◽  
Cellulose Acetate ◽  
Solid Phase ◽  
Inversion Method ◽  
Cellulose Acetate Membrane ◽  
Cellulose Acetate Membranes ◽  
Treatment Research ◽  
Non Fouling

<p><em>Industrial waste water area that flows in the River Flood Canal Semarang can affect the environment if not done processing. Membrane is one alternative water treatment technologies with the principle of filtration. The presence of fouling is a problem encountered in the use of the membrane. In this study will be made of non-fouling nanofiltration membranes made from cellulose acetate. Manufacture of cellulose acetate membrane is accomplished by phase inversion method, which is changing the shape of the polymer solid phase into the liquid phase rich in solvent into solids (membrane) which is rich in polymer. Therefore, the aim of this study was to create a non-fouling nanofiltration membrane using cellulose acetate polymer as well as assess the effect of PEG additives and pre-treatment with UV light to the surface of the structure and performance of cellulose acetate membranes for produced water treatment. Research using cellulose acetate membranes for wastewater treatment is done by varying the type of PEG 1500 and 4000, variations of PEG of 1, 3 and 5% by weight and a UV irradiation for 10, 20 and 30 seconds. The research followed by testing the performance of the membrane in wastewater treatment using a dead-end filtration with the parameters of flux and rejection. Characterization of the membrane was analyzed with SEM and FTIR. Analysis of the results was conducted to determine the levels of turbidity, TDS, COD, Ca<sup>2+</sup>, S<sup>2-</sup> and oil in waste water before and after passing through the membrane.</em><em></em></p>

scholarly journals Synthesis and Characterization of Blended Cellulose Acetate Membranes

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 4
Author(s):  
Abdullah M. Asiri ◽  
Francesco Petrosino ◽  
Valerio Pugliese ◽  
Sher Bahadar Khan ◽  
Khalid Ahmad Alamry ◽  
...  
Keyword(s):  
Contact Angle ◽  
Cellulose Acetate ◽  
Cross Sections ◽  
Mechanical Stability ◽  
Polymer Chains ◽  
Asymmetric Structure ◽  
Cellulose Acetate Membrane ◽  
Average Pore ◽  
Average Pore Radius ◽  
Cellulose Acetate Membranes

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 than the pure CA ones. Nevertheless, ZnO modified CA membranes have higher surface pore size, pore density and porosity, and improved surface hydrophilicity compared with pure CA membranes. The results indicated that the incorporated nano-ZnO tends to limit the packing of the polymer chains onto the membrane structure while showing antifouling properties leading to better hydrophilicity and permeation with consistent UF applications.

Development of Cellulose Acetate Membranes for Nano–and Reverse Osmosis Filtration of Contaminants in Drinking Water

2012 ◽  
Author(s):  
Darunee Bhongsuwan ◽  
Tripob Bhogsuwan ◽  
Narumol Buangam ◽  
Waneerat Mangkalatas
Keyword(s):  
Cellulose Acetate ◽  
Reverse Osmosis ◽  
Contaminated Water ◽  
Cellulose Acetate Membrane ◽  
Permeate Flux ◽  
Dead End ◽  
Cellulose Acetate Membranes ◽  
Stirred Cell ◽  
Iron Manganese ◽  
Iron And Manganese

Cellulose acetate (CA) membrane was produced from CA powder, formamid, and acetone. Annealing temperature of 80C and evaporation times of 30, 60, and 90 seconds were chosen in preparation of the CA membranes named R530, R560, and R590, respectively. The membranes were tested using a dead-end stirred cell for filtration of NaCl salt, iron, manganese, and arsenic in the laboratory-prepared water and groundwater. Results of the tests using a membrane R530 at 400 psi showed, that the rejection efficiencies for salt, iron, and manganese in laboratory-prepared water with 3000 ppm NaCl , 2.0 ppm Fe, and 2.0 ppm Mn were 87%, 99%, and 92%, respectively, with a permeate flux of 21 Lm-2hr-1. Tests for the groundwater containing 4815 ppm NaCl and 5.48 ppm Mn without acid treatment showed that membrane R530 gave the flux and rejection for salt and manganese at 24 Lm-2hr-1, 85% and 98%, and for iron and manganese at 21 Lm-2hr-1, 93% and 99%, respectively. In the filtration of arsenic, the prepared membrane had a As rejection of 68 - 70% at 300 and 400 psi when the feed was the laboratory prepared 1 ppm As+3 contaminated water but it was found to be more than 82 - 96% when the feed was a natural water. This is probably because the prepared membrane had a higher rejection efficiency for As+5 ions than As+3 ions. Ion selective capability of the CA membrane shows the potential to use the membrane in filtration of selective ions. Key words: Cellulose acetate membrane, reverse osmosis, nano-filtration, contaminated water, dead-end stirred cell

scholarly journals Role of Hydrogen-Bonding in Nonelectrolyte Diffusion through Dense Artificial Membranes

1969 ◽  
Vol 54 (3) ◽  
pp. 369-382 ◽  
Author(s):  
C. M. Gary-Bobo ◽  
R. DiPolo ◽  
A. K. Solomon
Keyword(s):  
Hydrogen Bonding ◽  
Cellulose Acetate ◽  
Solute Diffusion ◽  
Bathing Solution ◽  
Cellulose Acetate Membrane ◽  
Membrane Diffusion ◽  
Cellulose Acetate Membranes ◽  
Steric Configuration ◽  
Experimental Values

The diffusion of two series of alcohols and amides through complex cellulose acetate membranes was studied. The thin dense part of these membranes behaves as a nonporous layer of low water content. In this layer, called the skin, the solute diffusion coefficients, ω, depend upon size, steric configuration, and the partition coefficient, K8, between membrane and bathing solution. From the experimental values of ω and K8, the over-all friction, f, experienced by the solutes in the membrane was computed. It was found that f depends upon the chemical nature of the solute and is related to hydrogen-bonding ability. In the coarse, porous layer of the cellulose acetate membrane, diffusion occurs mainly through aqueous channels. In this instance also the hydrogen-bonding ability of the solute seems to exercise a smaller but significant influence.

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