Cellulose Acetate Membrane Research Articles

Solution blow co-spinning of cellulose acetate with poly(ethylene oxide). Structure, morphology, and properties of nanofibers

Cellulose acetate (CA) nanofibers are prepared using solution blow co-spinning (SBS) with poly(ethylene oxide) (PEO). The pure CA membranes are obtained by washing water-soluble PEO from the fibrous CA-PEO blend. Nanofibrous membranes are characterized using optical and scanning electron microscopy (SEM), differential scanning calorimetry (DSC), infrared spectroscopy (ATR-FTIR), and surface zeta potential measurements. Thermal transitions from DSC and ATR-FTIR spectra analysis were used to confirm the removal of the PEO. Although the characteristic signals of PEO are not observed by FTIR, an additional thermal step transition in CA nanofibers indicates the embedding of a small amount of PEO (up to 6 wt%). SEM analysis shows that CA-PEO blends are constituted by fibers with mean diameters from 671 to 857 nm (depending on the SBS parameters), while after PEO removal, diameters range from 567 to 605 nm. We propose a new method for staining CA-PEO membranes with iodine solution in absolute ethanol that allows the differentiation of CA and PEO components with an optical microscope. The microscopy results suggest that PEO assists in the spinning by enveloping CA nanofibers, allowing uninterrupted processing. The successful deacetylation to cellulose using an aqueous KOH solution is confirmed with zeta potential measurements and ATR-FTIR.

Fabrication and characterization of superhydrophilic graphene-based electrospun membranes for efficient oil-water separation

This research article investigates the fabrication of superhydrophilic graphene-based electrospun membranes for efficient oil-water separation. The study utilizes cellulose acetate (CA) as the base material for membrane fabrication, employing an electrospinning technique followed by the electrohydrodynamic atomization of graphene oxide (GO) to enhance their hydrophilicity. The surface morphology, water contact angle, and Fourier Transform Infrared (FTIR) spectra of the fabricated membranes were analyzed to assess their properties. The membrane characterization techniques revealed the successful integration of GO nanosheets on the surface of the highly porous interconnected nanofibrous matrix. The modified membranes exhibited superhydrophilicity and underwater oleophobicity. The water contact angle of the optimized GO-based electrospun CA membrane was reduced from 110° to zero within 3 s. The performance of the membranes was evaluated through oil-water separation experiments using different types of oils (such as toluene, n-decane, and hexane) in water. The results demonstrated that the graphene-based optimized membranes exhibited high separation efficiency (3820 LMH), with a water permeation flux as high as 65.5 % compared to CA membranes (2308 LMH). The efficiency of separation while using all three different oils with DI water was calculated to be >99.9 %. The study provides valuable insights into the use of graphene-based membranes for oil-water separation and highlights the potential of the electrohydrodynamic atomization technique for the surface modification of membranes. The developed membranes have great potential applications in various industries, including oil and gas, chemical, and wastewater treatment.

Constructed "sandwich" structure to obtain recyclability and high rejection rate high-flux CA@HMSN@h-BN/PDA membrane for efficient treatment of dye wastewater

It is necessary to develop a nanofiltration membrane that can remove dye molecules efficiently and is not easily polluted for the treatment of textile industry wastewater. A novel high-flux CA@HMSN@h-BN/PDA membrane with a "sandwich" structure was obtained by assembling the support layer of the Hollow mesoporous silica nanoparticles (HMSN), and the isolation layer of the h-BN/PDA on the Cellulose acetate (CA) membrane. HMSN was synthesized using ZIF-8 as a self-sacrificial template to provide improved permeability. h-BN/PDA obtained by modifying hexagonal boron nitride (h-BN) with polydopamine (PDA) brought higher hydrophilicity, rejection rate, and stability to the membrane. The study solved the problem that the membrane separation process requires sacrificing flux and recyclability for high rejection rates. CA@HMSN@h-BN/PDA membrane has a super-hydrophilic property (water contact angle of 22.5°) and high pure water flux (4419.4 L·m−2·h−1·bar−1). Meanwhile, the CA@HMSN@h-BN/PDA membrane achieves a high rejection rate (over 99.5%) due to the special "sandwich" structure. Through cycling experiments, CA@HMSN@h-BN/PDA membranes exhibit recyclability. More importantly, CA@HMSN@h-BN/PDA membranes maintain stable performance in complex environments, such as extremely acidic/alkaline or inorganic salt interference environments. Thus the CA@HMSN@h-BN/PDA membrane has the potential for future wastewater treatment.

Cellulose Acetate Membrane Synthesis of Banana Peel

The membranes can be synthesized from organic and inorganic materials. One of the based organic materials used was a cellulose acetate membrane from banana peel. Banana peel comprised 65% cellulose, and therefore it had the potential to be processed into a membrane. Cellulose acetate membranes are synthesized using a mixture of cellulose acetate from a banana skin with 55% acetone and 27% dimethylformamide using a phase inversion technique. SEM results pictured porous membranes with a pore size of about 5 μm. The results demonstrate the flux capability of a synthesized cellulose acetate membrane of 0.440 L / m2.h with a rejection coefficient of 97.6%. It was concluded that banana peel waste could be used as raw material to manufacture cellulose acetate membranes.

Synthesis of Hybrid Cellulose Acetate Membranes and Application of the Flynn-Wall-Ozawa Isoconversional Method

The synthesis of hybrid materials is a promising alternative in the production of materials with optimized properties. In this context, the classic cellulose acetate membranes are being modified. It is worth mentioning that knowing the thermal stability of cellulosic materials is an essential factor in their use since organic polymers have low thermal resistance, limiting their applicability. This work evaluates the synthesis and the study of the thermal degradation kinetics of hybrid cellulose acetate membranes. The synthesis was carried out using the sol-gel process, with the phase inversion technique, through the reaction of cellulose acetate with organometallic precursors: tetraethyl orthosilicate, TEOS; 3-aminopropyl triethoxysilane, APTES, and titanium isopropoxide, TiPOT, in fixed composition. Thermal characterization was performed with thermogravimetric analysis at different heating rates under a nitrogen atmosphere. The kinetic parameter of thermal decomposition activation energy, Ea, was estimated with the isoconversional method proposed by Flynn-Wall-Ozawa (FWO). The degradation kinetics shows that the change in the chemical composition of the samples directly interferes with their thermal properties. Thus, it is possible to observe that the activation energy found for the reference sample, AC-Pure, in the first and second batches was 233.5 and 219.05 kJ/mol, respectively. The composition modification results in an increase in activation energy, in which sample B0//100-30 recorded 310.31 and 226.05 kJ/mol in the first and second batches; and sample B100//0-30 reached 452.73 and 424.74 kJ/mol. It is clear that the increase in the thermal resistance of the samples is associated with the change in the chemical composition and must be attributed to the increase in the TEOS content in the composition due to the formation and increase in the presence of siloxane groups in the material.

Preparation and application of a chiral Am7CD-modified COF composite membrane by interfacial polymerization

Membrane separation technology has infinite potential to produce optically pure drugs. However, there are still challenges regarding chiral membranes, such as the single separation object, poor mechanical properties, and constrained relationship between permeability and enantioselectivity. To improve the membrane properties, heptakis (6-amino-6-deoxy)-β-CD-modified carboxyl-functionalized COF (TpBD-Am7CD) was introduced as a chiral functional material for the preparation of a TpBD-Am7CD stainless steel I-Net cellulose acetate membrane (COF/SSCAM) via interfacial polymerization. Using tryptophan as the template molecule, the membrane preparation and filtration conditions were optimized to achieve maximum enantioselectivity. The optimized COF/SSCAM achieved a better enantiomeric excess percentage (e.e.% = 100.00%) and solute permeation flux (JS = 37 × 10−6 mol m−2 h−1) for racemic tryptophan than the support membrane, which was attributed to the enantioselectivity and hydrophilicity of TpBD-Am7CD. Moreover, COF/SSCAM achieved enantiomeric separation of racemates of propranolol, warfarin, atenolol, and metoprolol, and the e.e.% values were 39.51%, 5.60%, 16.04%, and 3.09%, respectively. In addition, the chiral recognition mechanism was investigated by molecular docking simulation.

Constructing superwetting membranes by sodium lignosulfonate-modified carbon nanotube for highly efficient crude oil-in-water emulsions separations

For the past few years, superwetting materials had been developed to enhance the treatment process of oily wastewater. Membranes are improved through the combination of surface topography and chemical modifications to achieve superwetting properties for treating oily wastewater effectively. In this work, we prepared an eco-friendly membrane by depositing sodium lignosulfonate (SLS)-modified carbon nanotube (CNT) on a cellulose acetate membrane via vacuum filtration without employing any organic solvents. The SLS@CNT membrane shows superhydrophilicity and underwater superoleophobicity with high stability. Furthermore, the SLS@CNT membrane exhibits outstanding antifouling and self-cleaning properties against crude oil of high viscosity. Most importantly, our SLS@CNT membrane exhibits outstanding oil-in-water emulsions separation performances including crude oil-in-water emulsions. For the surfactant-free and surfactant-stabilized emulsions, fluxes were revealed to reach up to 27,800 L m−2 h−1 bar−1 and 13,800 L m−2 h−1 bar−1, respectively, with very high separation efficiency (>99.97 % and 99.79 %, respectively). The distinguished performance of our SLS@CNT membrane, and its eco-friendly, low-energy consumption, and cost-effective preparation, demonstrate practical applicability.

Electrospray fabrication of anti-fouling nanocellulose desalination membrane with high flux

Cellulose acetate (CA) desalination membranes encounter poor fouling resistance and water permeability, which can be mitigated by modifying their surfaces. Herein, we demonstrate highly controllable membrane porosity and thickness by introducing electrospray-mediated coating of cellulose nanocrystals (CNCs). The results revealed that due to the increased porosity from CNC plasticizing effect, the pure water permeability coefficient reached as high as 7.89 L m−2 h−1 bar−1 with one electrospray scan of 0.50% w/v CNC, while retaining above 80% ion rejection efficiencies (Na+, Mg2+, Cl−, and SO42−) against brackish water. The hydrophilic CNC coordinated the preparation of a low viscoelastic and swollen active layer associated with improved fouling resistance, remarkably achieving as high as 96.3% flux recovery and 88.1% reduction in bacterial colonization with 0.50% CNC-coated CA membrane. The excellent desalination performance of CNC electrospray-coated membranes was found to be comparatively higher than any other CA membranes reported in literature. Therefore, this study aims to provide future guidelines on how to effectively improve antifouling and water flux properties using electrospray technique and CNC nanofillers.

Fabrication of Cellulose Acetate-Based Proton Exchange Membrane with Sulfonated SiO2 and Plasticizers for Microbial Fuel Cell Applications.

Developing a hybrid composite polymer membrane with desired functional and intrinsic properties has gained significant consideration in the fabrication of proton exchange membranes for microbial fuel cell applications. Among the different polymers, a naturally derived cellulose biopolymer has excellent benefits over synthetic polymers derived from petrochemical byproducts. However, the inferior physicochemical, thermal, and mechanical properties of biopolymers limit their benefits. In this study, we developed a new hybrid polymer composite of a semi-synthetic cellulose acetate (CA) polymer derivate incorporated with inorganic silica (SiO2) nanoparticles, with or without a sulfonation (-SO3H) functional group (sSiO2). The excellent composite membrane formation was further improved by adding a plasticizer (glycerol (G)) and optimized by varying the SiO2 concentration in the polymer membrane matrix. The composite membrane's effectively improved physicochemical properties (water uptake, swelling ratio, proton conductivity, and ion exchange capacity) were identified because of the intramolecular bonding between the cellulose acetate, SiO2, and plasticizer. The proton (H+) transfer properties were exhibited in the composite membrane by incorporating sSiO2. The composite CAG-2% sSiO2 membrane exhibited a higher proton conductivity (6.4 mS/cm) than the pristine CA membrane. The homogeneous incorporation of SiO2 inorganic additives in the polymer matrix provided excellent mechanical properties. Due to the enhancement of the physicochemical, thermal, and mechanical properties, CAG-sSiO2 can effectively be considered an eco-friendly, low-cost, and efficient proton exchange membrane for enhancing MFC performance.

Evaluation of CAP@CS nanoparticles infused cellulose acetate membrane and their invitro antidiabetic, anticancer and antibacterial activity

Cancer drugs with pharmacological activity can be found in many different natural sources. Invitro and invivo research have shown that capsaicin incorporated chitosan nanoparticles (CAP@CS) have anticancer properties. CAP's medicinal potential is limited by its poor water solubility and bioavailability. This research presents the synthesis and characterization of CAP@CS nanoparticles encapsulated in a cellulose acetate membrane (CAP@CS/CA) for potential use in cancer therapy and the treatment of diabetes. The synthesized CAP@CS/CA membrane was analyzed using Scanning Electron Microscopy, Thermogravimetric analysis, mechanical strength testing, and drug release studies. Renal cell carcinoma (ACHN) cancer cell lines were used to test the efficacy of the synthesized CAP@CS/CA membrane in inhibiting tumor growth. These findings point to the synthesized CAP@CS/CA membrane as a potential new therapeutic agent for treating skin cancer and for its antibacterial properties. The capacity of the CAP@CS/CA membrane to inhibit carbohydrate digesting enzymes such a-amylase with IC50 values as low as 62.5 mg/mL−1 demonstrates its antidiabetic efficacy. We conclude that the CAP@CS/CA membrane has promising potential antidiabetic potential against important diabetes enzymes and is a perfect nanomedicine for nano-biomedical applications.

Simple Bioparticle Filtration Device Based on an Ultralow-Fouling Zwitterionic Polyurethane Membrane for Rapid Large-Volume Separation of Plasma and Viruses from Whole Blood

Plasma separation from whole blood is oftent required as an essential first step when performing blood tests with a viral assay. However, developing a point-of-care plasma extraction device with a large output and high virus recovery remains a significant obstacle to the success of on-site viral load tests. Here, we report a portable, easy-to-use, cost-efficient, membrane-filtration-based plasma separation device that enables rapid large-volume plasma extraction from whole blood, designed for point-of-care virus assays. The plasma separation is realized by a low-fouling zwitterionic polyurethane-modified cellulose acetate (PCBU-CA) membrane. The zwitterionic coating on the cellulose acetate membrane can decrease surface protein adsorption by 60% and increase plasma permeation by 46% compared with a pristine membrane. The PCBU-CA membrane, with its ultralow-fouling properties, enables rapid plasma separation. The device can yield a total of 1.33 mL plasma from 10 mL whole blood in 10 min. The extracted plasma is cell-free and exhibits a low hemoglobin level. In addition, our device demonstrated a 57.8% T7 phage recovery in the separated plasma. The results of real-time polymerase chain reaction analysis confirmed that the nucleic acid amplification curve of the plasma extracted by our device is comparable to that obtained by centrifugation. With its high plasma yield and good phage recovery, our plasma separation device provides an excellent replacement for traditional plasma separation protocols for point-of-care virus assays and a broad spectrum of clinical tests.

Retraction Note: Pb(II) and Cd(II) removal, mechanical and morphological features of nanofibrous membranes of cellulose acetate containing fillers of hydroxyapatite, graphene oxide, and magnetite

Retraction Note: Pb(II) and Cd(II) removal, mechanical and morphological features of nanofibrous membranes of cellulose acetate containing fillers of hydroxyapatite, graphene oxide, and magnetite

Preparation and Characterization of Biodegradable Cellulose Acetate‐Fibroin for Dialysis Application

AbstractMembrane separation technology is an efficient and high‐performance technique. It is a thin flat sheet and acts like a delicate barrier for the selective transport of substances under the influence of pressure. Low cost and various applications in industry as well as in medical make it more important. The basic property of a dialysis membrane is the ability to remove toxic materials from blood in minimum time, and maximum protein rejection, and must have the ability to moderate the water flux. Protein deposition or adsorption on the surface of the membrane results in low flux and change of selectivity of membrane for low toxic removal. In this work we prepared cellulose acetate membrane through the phase inversion method. The effects of additives are characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infra‐Red (FT‐IR), and Contact Angle. The membrane performance is also studied in pure water flux, water uptakes, porosity, BSA rejection, and Urea clearance test. This membrane is modified by adding various types of organic and inorganic additives which will perform specific functions. M‐3 membrane showed excellent results its hydrophilicity is 133.33 %, leaching point is 2.08, pure water permeation flux 97.19 L/m2h, porosity is 13.97 nm, BSA rejection value is 91 % and Urea clearance is 92 %. These results show that M‐3 is excellent for dialysis operations.

Mixed Matrix Cellulose Acetate Membrane Incorporated with Poly(amidoamine) Dendrimer Functionalized Multiwalled Carbon Nano Tubes for Effective Anionic Dyes Rejection

Mixed Matrix Cellulose Acetate Membrane Incorporated with Poly(amidoamine) Dendrimer Functionalized Multiwalled Carbon Nano Tubes for Effective Anionic Dyes Rejection

The fragmented 3D-covalent organic framework in cellulose acetate membrane for efficient phenol removal

The membrane-based separation of molecular pollutants has several advantages such as minimum energy utilization, recyclability, and commercial viability. However, the membrane fabrications should be in line with the suitable porosity, functionality, mechanical strength, and economical for their practical applications. Herein, we report a novel hybrid membrane (TamDbta-CA) of low-cost cellulose acetate (CA) polymer and functionally diverse porous defective 3D-COF (TamDbta) for the removal of toxic phenol from industrially relevant synthetic oil-produced water. The low percentage (0.8%) use of TamDbta as pillars in CA-membranes improved the porosity, hydrophilicity, mechanical strength, and separation efficiency of phenol (∼80 to 90 %). The defective functional sites (–C=O and –Br) and nanoporosity of TamDbta and its uniform distribution throughout the mixed-matrix membrane contributed to the enhancement of membrane performance. The strategic membrane design and its efficient use for removing toxic pollutants may pave the way for using COFs as a pillar in commercially viable membranes.

Functionalisation of Electrospun Cellulose Acetate Membranes with PEDOT and PPy for Electronic Controlled Drug Release.

Controlled drug release via electrical stimulation from drug-impregnated fibres was studied using electrospun cellulose acetate (CA) membranes and encapsulated ibuprofen (IBU). This research outlines the influence of polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT)-functionalised CA membranes and their suitability for dermal electronic-controlled drug release. Micro Raman analysis confirmed polymer functionalisation of CA membranes and drug incorporation. Scanning electron microscopy (SEM) images evidenced the presence of PPy and PEDOT coatings. The kinetic of drug release was analysed, and the passive and active release was compared. In the proposed systems, the drug release is controlled by very low electrical potentials. A potential of -0.3 V applied to membranes showed the ibuprofen retention, and a positive potential of +0.3 V, +0.5 V, or +0.8 V, depending on the conductive polymer and membrane configuration, enhanced the drug release. A small adhesive patch was constructed to validate this system for cutaneous application and verified an "ON/OFF" ibuprofen release pattern from membranes.

Tailoring Zeolite-Composite (ZC) Impregnated Thermally Endured Nonporous Cellulose Acetate Membranes for Potential Gas Separation and Antibacterial Performances

Cellulose acetate (CA) composite membranes are tailored for potential gas-transportation and antibacterial activity by incorporating various ratios (0-8wt. %) of zeolite-CuO (10:1, ZC) composite. The aim behind this is to develop an anti-biofouling membrane with enhanced CO2permeation and selection properties. In situ coprecipitation route is adopted to synthesize ZC that imparted morphological, structural, thermal, and performance characteristics of membranes synthesized by solution casting mechanism. FESEM analysis revealed, pores size transformed from 1µm to 1.4 nm as observed in M0 (virgin) and M4 (8wt. % ZC) membranes, respectively. The existence and linkages of impregnated ZC in the developed membranes are verified by FTIR investigations. TGA-tested thermally endured membranes are tested for gas permeation/selectivity. In comparison to virgin CA membrane, three folds enhancements in CO2permeation and two folds in CO2/N2selectivity are observed. Membranes are also evaluated for antibacterial test against ‘gram-negative bacteria’ elucidates that increasing ZC content in composite membranes exhibit remarkable results.

Manganese spinel ferrites‐composite nanotubes impregnated thermally endured cellulose acetate membranes for superior desalination application

AbstractManganese nanoferrites are decorated over single‐wall carbon nanotubes using in situ co‐precipitation technique to incorporate into cellulose acetate (CA) polymer in order to prepare nanocomposite membranes for salt rejection and desalination purpose. The microstructural study reveals the pore size of the synthesized membranes from 5 nm to 0.20 μm depending upon the loading concentration of the impregnated nanocomposite tubes. Fourier transform infrared (FTIR) and X‐ray diffraction (XRD) patterns of the synthesized membranes delineate the presence of decorated nanotubes in the host polymer matrix. Thermal degradation study proclaims the thermal endurance enhancement with increasing nanotubes concentration in the polymer matrix. Flux rate of the deionized (DI) water through the prepared membranes decreases with increasing nano‐filler concentration while this impact is observed inverse in salt rejection study of the aluminum sulphate (Al2(SO4)3) and zinc sulphate (ZnSO4) solutions due to the transformation of microporosity to nanoporosity with increasing composite tubes dosing into the host CA polymer.

Magnesium Ortho-Vanadate/Magnesium Oxide/Graphene Oxide Embedded through Cellulose Acetate-Based Films for Wound Healing Applications.

A multifunctional nano-films of cellulose acetate (CA)/magnesium ortho-vanadate (MOV)/magnesium oxide/graphene oxide wound coverage was fabricated. Through fabrication, different weights of the previously mentioned ingredients were selected to receive a certain morphological appearance. The composition was confirmed by XRD, FTIR, and EDX techniques. SEM micrograph of Mg3(VO4)2/MgO/GO@CA film depicted that there was a porous surface with flattened rounded MgO grains with an average size of 0.31 µm was observed. Regarding wettability, the binary composition of Mg3(VO4)2@CA occupied the lowest contact angle of 30.15 ± 0.8o, while pure CA represents the highest one at 47.35 ± 0.4°. The cell viability % amongst the usage of 4.9 µg/mL of Mg3(VO4)2/MgO/GO@CA is 95.77 ± 3.2%, while 2.4 µg/mL showed 101.54 ± 2.9%. The higher concentration of 5000 µg/mL exhibited a viability of 19.23%. According to optical results, the refractive index jumped from 1.73 for CA to 1.81 for Mg3(VO4)2/MgO/GO@CA film. The thermogravimetric analysis showed three main stages of degradation. The initial temperature started from room temperature to 289 °C with a weight loss of 13%. On the other hand, the second stage started from the final temperature of the first stage and end at 375 °C with a weight loss of 52%. Finally, the last stage was from 375 to 472 °C with 19% weight loss. The obtained results, such as high hydrophilic behavior, high cell viability, surface roughness, and porosity due to the addition of nanoparticles to the CA membrane, all played a significant role in enhancing the biocompatibility and biological activity of the CA membrane. The enhancements in the CA membrane suggest that it can be utilized in drug delivery and wound healing applications.

MIL-100 (Fe) integrated fibrous polyvinyl alcohol graft on cellulose acetate towards the development of green membranes; Application in multi solute rejection

Biodegradable cellulose acetate (CA) based membrane is grafted with poly(vinyl alcohol) (PVA) which is stabilized by citric acid (ca) (via electrospinning) and cured thermally to obtain water stable, robust cross-linked CA membrane. A high surface area metal organic framework (MOF) namely MIL-100(Fe) is electrospun with PVA nanofiber to achieve more functionalized nanocomposite grafting. Thermal curing allows cross-linking between the functional groups of CA, PVA and MOF which facilitates grafted PVA nanofibers to remain intact on the CA surface during filtration. The physicochemical properties and morphology of composite membranes are determined using various spectroscopy and microscopy tools. The performance of electrospun membrane composites were assessed for the treatment of humic acid (HA), heavy metal ions, dyes and sulfate salts. The results indicate that the hydrophilicity of membranes enhanced significantly upon coating a MOF functionalized nanofiber layer on CA membrane. The prepared composite membranes show rejection efficiency of > 90% for HA, Pb2+ and Cd2+ and nearly 70% for MgSO4 and Na2SO4 salts. Remarkable flux up to ten times more than the recently reported nanofiber reinforced membranes is achieved. In summary, this study provides an insight into designing of effective CA membranes by engineering various MOF - electrospun nanofibers for greater permeability and removal of various solutes.