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.

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 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.

Effect of Membrane Pore Size and Membrane-Solute Interactions on Lysozyme Ultrafiltration

2006 ◽  
Vol 514-516 ◽  
pp. 1483-1487
Author(s):  
Vitor Magueijo ◽  
Viriato Semião ◽  
Maria Norberta de Pinho
Keyword(s):  
Molecular Weight ◽  
Pore Size ◽  
Pore Radius ◽  
Double Layers ◽  
Hydraulic Permeability ◽  
Average Pore ◽  
Average Pore Radius ◽  
Electric Double Layers ◽  
Membrane Pore ◽  
Cellulose Acetate Membranes

A model based on steric hindrance mechanisms [1] is used to determine the pore sizes of two ultrafiltration (UF) membranes. The lysozyme rejection coefficients of those membranes are predicted through the same model after modification of the pore size and solute radius by taking into account the development of electric double layers. Two asymmetric cellulose acetate membranes M1 and M2 were prepared and characterized. Membrane M1 has an hydraulic permeability of 2.1x10-6 m/s/bar, a molecular weight cut-off (MWCO) of 30,000 Da and an average pore radius of 2.6 nm. Membrane M2 has an hydraulic permeability of 5.9x10-6 m/s/bar, a molecular weight cut-off (MWCO) of 60,000 Da and an average pore radius of 5.3 nm. Aqueous solutions of lysozyme containing a NaCl concentration of 0.1M were ultrafiltrated through membranes M1 and M2. The predicted lysozyme rejections considering the development of electric double layers on the protein and membrane pore surfaces, are in good agreement with the experimental results.

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>

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.

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.

Dialysis experiments with asymmetric cellulose acetate membranes

1988 ◽  
Vol 53 (6) ◽  
pp. 1247-1259
Author(s):  
Hans-Hartmut Schwarz ◽  
Jaromír Lukáš ◽  
Jiří Vacík
Keyword(s):  
Cellulose Acetate ◽  
Cross Section ◽  
Membrane Structure ◽  
Phase Inversion ◽  
Solution Concentration ◽  
Diffusion Permeability ◽  
Asymmetric Structure ◽  
Cellulose Acetate Membranes ◽  
The Asymmetry ◽  
Dialysis Time

Cellulose acetate membranes for ultrafiltration produced by phase inversion have an asymmetric structure in the cross-section. In spite of this assymetry it is possible to characterize such membranes by dialysis. The asymmetry has no influence on the permeability for solute poly(oxyethylene). The membrane structure was varied systematically by annealing. The influence of solution concentration, dialysis time and temperature was also investigated. Statements are made on the annealing influence. A relationship between diffusion permeability and the true rejection is discussed.

Clinical Evaluation of a New High-Flux Cellulose Acetate Membrane

1989 ◽  
Vol 12 (2) ◽  
pp. 85-90 ◽  
Author(s):  
R. M. Schaefer ◽  
L. Huber ◽  
U. Gilge ◽  
K. Bausewein ◽  
J. Vienken ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Cellulose Acetate ◽  
High Capacity ◽  
Cellulose Acetate Membrane ◽  
High Flux ◽  
Major Goal ◽  
Dialysis Therapy ◽  
Removal Capacity ◽  
Cellulose Acetate Membranes ◽  
Pmn Leukocytes

One major goal of dialysis therapy has become the removal of ß2-microglobulin (ß2-m). The interdialytic elimination of ß2-m was studied using a newly developed high-flux cellulose acetate (CA) membrane. The results show that high-flux CA dialyzers offer better biocompatibility than classical Cuprophan or high-flux Cuprophan devices, with regard to leukopenia, C3a desarg generation, and elastase release from polymorphonuclear (PMN) leukocytes. Compared to high-flux CA membranes, high-flux PMMA membranes induce less C3a desarg formation but comparable leukopenia. High-flux PMMA membranes, however cause greater leukocyte stimulation than CA as demonstrated by more PMN elastase release during hemodialysis. Using high-flux CA or high-flux PMMA membranes, serum ß2-m levels decreased 32% during dialysis. Serum ß2-m dropped 10% with high-flux Cuprophan membranes, but remained unchanged with conventional Cuprophan dialyzers. Sieving coefficients for ß2-microglobulin (ß2-m) were virtually zero with classical Cuprophan and 0.66 with high-flux cellulose acetate membranes. High-flux membranes made of Cuprophan and PMMA gave coefficients of 0.25 and 0.45, respectively. This indicates the high removal capacity of the new CA-membrane for substances with high molecular weight. This high-flux CA membrane thus appears to combine a good degree of biocompatibility with a high capacity for ß2-m removal.

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