Cellulose Acetate Fibers Research Articles

Nanostructured Affinity Membrane to Isolate Extracellular Vesicles from Body Fluids for Diagnostics and Regenerative Medicine.

Electrospun regenerated cellulose (RC) nanofiber membranes were prepared starting from cellulose acetate (CA) with different degrees of substitution. The process was optimized to obtain continuous and uniformly sized CA fibers. After electrospinning, the CA membranes were heat-treated to increase their tensile strength before deacetylation to obtain regenerated cellulose (RC). Affinity membranes were obtained by functionalization, exploiting the hydroxyl groups on the cellulose backbone. 1,4-Butanediol-diglycidyl ether was used to introduce epoxy groups onto the membrane, which was further bioconjugated with the anti-CD63 antibody targeting the tetraspanin CD63 on the extracellular vesicle membrane surface. The highest ligand density was obtained with an anti-CD63 antibody concentration of 6.4 µg/mL when bioconjugation was performed in carbonate buffer. The resulting affinity membrane was tested for the adsorption of extracellular vesicles (EVs) from human platelet lysate, yielding a very promising binding capacity above 10 mg/mL and demonstrating the suitability of this approach.

Cellulose acetate fibers as corrosion inhibitor delivery system for carbon steel

This study evaluated the effectiveness of electrospun cellulose acetate fibers (CAFs) containing oleic acid (OA) for corrosion inhibition on carbon steel in chloride-rich environments. By varying the OA content, CAFs of different thicknesses were produced. Potentiodynamic polarization showed that steel coated with OA-containing CAFs had enhanced corrosion resistance, with higher corrosion potential (Ecorr) and lower corrosion current density (icorr). The electrochemical impedance spectroscopy (EIS) results for the dip-coated sample showed an impedance increase of approximately 20× (from 2 to 40 kΩ cm2), and a capacitance reduction from 10−6 to 10−8 F cm−2, compared to the untreated sample. The protective effect remained even after 48 h of exposure. These findings suggest CAFs as effective carriers for delivering OA inhibitors, offering a promising solution for corrosion mitigation in saline environments.

Cellulose Acetate and Polycaprolactone Fibre Coatings on Medical-Grade Metal Substrates for Controlled Drug Release.

This study explores a method that has the potential to be cost effective in inhibiting biofilm formation on metallic prostheses, thereby preventing rejection or the requirement for replacement. A cost-effective metal alloy used in biomedical implants was chosen as the substrate, and ibuprofen (Ibu), a well-known anti-inflammatory drug, was selected for drug release tests for its widespread availability and accessibility. Multilayer coatings consisting of cellulose acetate (CA), polycaprolactone (PCL), and chitosan (CHI), with or without ibuprofen (Ibu) content, were applied onto medical-grade stainless steel (SS-316 type) through electrospinning, electrospray, or blow spinning. The adhesion of the CA, PCL, and layered CA/PCL membranes, with thicknesses ranging from 20 to 100 μm, to SS substrates varied between 0.15 N and 0.22 N without CHI, which increased to 0.21 and 0.74 N, respectively, when a CHI interlayer was introduced by electrospraying between the SS and the coatings. Although drug release in a simulated body fluid (SBF) medium is predominantly governed by diffusion-driven mechanisms in all single- and multilayer coatings, a delayed release was noted in CA coatings containing Ibu when overlaid with a PCL coating produced by blow spinning. This suggests avenues for further investigations into combinations of multilayer coatings, both with and without drug-imbued layers.

Effect of calcium stearate on cellulose acetate-based mortars

The purpose of this study is to investigate the properties of cellulose acetate-based mortars with the addition of calcium stearate (CS), superplasticizer (SP) and metakaolin (MK). Previous research has shown that cellulose acetate (CA) fibers from industrial cigarette butts (CB) treatment can be incorporated into standard mortars at a rate of 1.3 wt%. CS was added in various proportions by weight (0.5, 1, 1.5 wt%), and their influence on cement hydration and microstructure was studied using various investigative techniques. The addition of CS was found to be beneficial in reducing the amount of water absorbed by CA, despite the significant absorption of these fibers. Furthermore, a CS rate of 1 wt% decreased CA-based mortar shrinkage. Additionally, 1 wt% CS improved by 18% the compressive strength of CA-based mortars manufactured with SP compared to the reference CA-mortar. CA fibers and CS seem to modify mortar microstructure by creating a plurimodal pore size distribution and reducing capillary pores. The CS addition, however, resulted in more cracks and reduced workability due to the weakening of the bond between the cement paste components. MK-mortars showed a slight 15% reduction in compressive strength and 13% reduction in bending strength; along with a 20% increase in shrinkage. By incorporating CA fibers as an additive along with CS or MK, CA-based mortars can improve some properties, including shrinkage and mechanical strength. Further, this approach offers a potential solution to CB pollution by reducing the environmental impact of this waste.

Removal of Mo(VI), Pb(II), and Cu(II) from wastewater using electrospun cellulose acetate/chitosan biopolymer fibers

Environmentally friendly polymers such as cellulose acetate (CA) and chitosan (CS) were used to obtain electrospun fibers for Cu2+, Pb2+, and Mo6+ capture. The solvents dichloromethane (DCM) and dimethylformamide (DMF) allowed the development of a surface area of 148 m2 g−1 for CA fibers and 113 m2 g−1 for cellulose acetate/chitosan (CA/CS) fibers. The fibers were characterized by IR-DRIFT, SEM, TEM, CO2 sorption isotherms at 273 K, Hg porosimetry, TGA, stress-strain tests, and XPS. The CA/CS fibers had a higher adsorption capacity than CA fibers without affecting their physicochemical properties. The capture capacity reached 102 mg g−1 for Cu2+, 49.3 mg g−1 for Pb2+, and 13.1 mg g−1 for Mo6+. Furthermore, optimal pH, adsorption times qt, and C0 were studied for the evaluation of kinetic models and adsorption isotherms. Finally, a proposal for adsorbate-adsorbent interactions is presented as a possible capture mechanism where, in the case of Mo6+, a computational study is presented. The results demonstrate the potential to evaluate the fibers in tailings wastewater from copper mining.

Cost-effective moisture-induced electrical power generators for sustainable electrodialysis desalination

To establish a sustainable method for desalination, it is necessary to explore and use renewable energy sources that are cost-effective and unaffected by weather conditions. Therefore, in this study we propose a novel hybrid electrodialysis system for environmentally friendly and cost-effective desalination of blackish water, integrating moisture-induced electrical power generators (MIEPGs). By coating a layer of carbon black on the surface of cellulose acetate fiber columns, which are readily available as cigarette filters, compact MIEPGs can be conveniently fabricated. These MIEPGs can generate electricity from trace amounts of moisture by leveraging the streaming potential induced along nanoscale channels between the carbon black particles. A notable voltage output (13.5–22 V) is achieved from the series connection of 90 cells using a customized module frame. The substantial power output derived from the stacked MIEPGs enables the successful desalination of modeled brackish water with a salt removal ratio of 92%.

Binary fiber membranes with dual transport channels and interfacial demulsification for continuous emulsion separation

Membrane fouling occurred during subsequent filtration weakens the application advantages of membrane separation technology in treating oil–water emulsions. Herein, a functionalized binary fiber membrane with dual transport channels and enhanced interfacial demulsification was fabricated to facilitate continuous emulsion separation. The interpenetrated cellulose acetate (CA) and polytetrafluoroethylene (PVDF) fibers offer independent channels for transferring water and oil in the binary fiber membrane, which enables the timely removal of continuous oil contamination to mitigate membrane fouling. Moreover, a Span 80 functional layer assembled on the binary fiber membrane by a solvent-induced grafting approach promotes dynamic interfacial demulsification and antifouling of membrane materials. Owing to the advantages of the dual oil–water transport channel and Span 80 functional demulsification layer, the binary fiber membrane can separate continuously emulsifier-stabilized oil-in-water emulsions. Consequently, the binary fiber membrane can handle emulsions with high oil content (>5 vol%), and a single-stage separation time can last up to 5 h with a separation efficiency of over 98% because of its dynamic antifouling properties. Significantly, the membrane exhibits desirable cycling performance, and the Span 80 functional layer can be easily assembled to reset the separation performance, which encourages continuous emulsion separation and an extended membrane service life. Overall, this work opens a new avenue to fabricate binary fiber membranes with dual transport channels for sustainable antifouling and continuous emulsion separation, with high potential in practical applications relating to oily wastewater treatment and fuel purification.

Electrospun Materials Based on Cellulose Acetate Loaded with Rosmarinic Acid with Antioxidant and Antifungal Properties.

Fibrous cellulose acetate (CA) materials loaded with rosmarinic acid (RA) were successfully created by one-pot electrospinning. In order to improve the water solubility of the polyphenolic acid and to facilitate its release from the fibrous materials, the non-ionic water-soluble polyethylene glycol (PEG) was added. Detailed characterization of the fabricated fibrous CA/RA and CA/PEG/RA materials was performed using scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), UV-Vis spectroscopy and water contact angle analysis. The optimal ratio between CA, RA and PEG for preparation of defect-free and uniform fibers was accomplished by varying their concentrations. Furthermore, the incorporation of the PEG improved the hydrophilicity and wettability of the fibrous CA materials. Moreover, PEG facilitated the RA release and over 360 min, the amount released from fibrous CA/PEG/RA fibers was 91%, while that released from CA/RA materials was 53%. Both of the RA-containing fibrous materials, with and without PEG, manifested high antioxidant activity as determined by the DPPH free radical-scavenging method. In addition, the electrospun CA/PEG/RA materials displayed good antifungal activity against C. albicans. These features make the fibrous CA/PEG/RA materials promising candidates for treatment of wound infections.

Regeneration of Pea-Pod-Like Cellulose Acetate Fibers as Aerogel-Derived Boards for Building Thermal Regulation and Carbon Reduction

Regeneration of Pea-Pod-Like Cellulose Acetate Fibers as Aerogel-Derived Boards for Building Thermal Regulation and Carbon Reduction

Smart win–win waste management: superhydrophobic filter using valorized cellulose acetate from discarded cigarette butts for cleaning up marine oil spill at Hurghada Red Sea shore in Egypt

The essential target of academics and the industrial sector is the innovation of an industrial ecology approach. Worldwide, cigarette butts (CBs) comprise the most predominant form of litter that spreads into the ecosystem and inland. In the meantime, oil is spilled into marine life from various activities and transportation. The result is a complex oil–water composition in a high concentration that causes severe hazards to the environment and to aquatic life. In this regard, the current investigation focuses on obtaining hydrophobic cellulose acetate from CBs for use as a filter media. The filter is applied in marine oil spill separation as a win–win industrial ecology technique. Initially, the separated CB residuals were prepared by successive washing. Subsequently, the obtained cellulose acetate fibers were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Furthermore, the new CB-based filters were used in the separation/adsorption of marine oil wastewater spill. Subsequently, a group of experiments were conducted. The results showed that the cleanup efficiency could be up to 99% in terms of chemical oxygen demand (COD). Moreover, the products were recovered by washing with hot water for further use, which showed high removal activity that reached 95% after successive uses. In comparison to commercial oil sorption materials, the results were promising as the RP-C18 cartridge revealed a maximum oil removal of 90%. Such preliminary data on a cellulose acetate filter scheme are a good indicator in the development of an oil spill facility, being a suitable candidate for controlling oil wastewater effluent streams.

Carbon Threads Supercapacitors for Washable e-Textile Applications: Configurations and Electrochemical Performance.

Technological solutions for emerging e-textiles are being sought to enable e-wear technology to be self-sustaining and lightweight. A rippling 1D carbon fiber capacitor design was made with commercial carbon threads as electrodes using simulated sweat solution as the electrolyte. This is particularly relevant for potential sports textile applications in which sweat could serve as an electrochemical energy source. An electrospun cellulose acetate fiber membrane and a commercially available felt were used as separators capable of soaking the electrolyte. These were tested in braided and woven electrode configurations, respectively. Functionalizing the carbon wires with polypyrrole (PPy) enhanced the surface area and significantly increased the specific capacity by approximately an order of magnitude (0.62 F/g). Cyclic voltammetry and charge-discharge tests confirmed the washability and durability of the devices for at least 1000 cycles.

Surface plasma modification of cellulose acetate fiber filter for the adsorption of typical components in smoke components.

Surface modification of cellulose acetate filter rods with low temperature plasma was performed to explore the retention and adsorption effect of modified filter rods on typical components (CO, H2O, benzene, and formaldehyde) in cigarette smoke. The surface structure and composition of the cellulose acetate filter rods were modified by changing the plasma treatment time. The modified filter rods were characterized by N2 physical adsorption (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), contact angle of H2O, Fourier transform infrared spectroscopy (FTIR) and in situ DRIFTS. Various functional groups were found on the surface of filter rods with the introduction of plasma modification, which exhibited strong retention performance for water vapor in cigarette smoke at room temperature and significantly enhanced adsorption for harmful substances (CO, benzene, and formaldehyde) in cigarette smoke.

ENHANCED MECHANICAL AND THERMAL PROPERTIES OF ELECTROSPUN CELLULOSE ACETATE FIBER MEMBRANES INCORPORATING PAHAE NATURAL ZEOLITE

In recent decades, fiber membranes have garnered significant attention and found numerous applications across various fields. This work used the electrospinning method to create fiber membranes with cellulose acetate (CA) as a primary polymer material. The characteristics of the fiber membrane, such as mechanical and thermal properties, were investigated by incorporating Pahae Natural Zeolite (PNZ) microparticles into the CA matrix. The fiber membranes' mechanical properties are improved by adding PNZ to the CA matrix, and the CA/PNZ 10% exhibits the maximum tensile strength of 0.97 MPa and elongation at a break of 4.52%. Meanwhile, incorporating PNZ filler into CA fiber membranes significantly enhances their thermal stability. This improvement is attributed to the formation of hydrogen bonds between CA and PNZ, as evidenced by the increasing residue values with higher PNZ content. Specifically, the residue of pure CA membrane fiber is 13.46%, which increases to 44.06% for CA/PNZ 15% fiber membranes. These favorable thermal and mechanical properties of the fiber membranes indicate the promising potential of CA/PNZ based membranes for filtration applications.

Electrospun Cellulose Acetate Nanofibers Containing Clinacanthus nutans (Phayayo) Crude Extract as Potential Wound Dressings

Extraction of Clinacanthus nutans (Burm.f.) lindau (C. nutans) or Phayayo (PY) leaves was performed by maceration using ethanol as an extractant. The antioxidant activity was evaluated by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. The inhibitory concentration at 50% antioxidant activity (IC50) of PY extract was 15.62 mg/mL. The electrospun cellulose acetate (CA) nanofibers containing PY extract at concentrations of 2.5, 5, and 7.5% w/v and silver (Ag) nanoparticles at 0.1% w/v were fabricated. The addition of PY extract and Ag influenced the viscosities of solutions and therefore affected the morphology and fiber diameters. The electrospun CA fiber mat containing 0.1% Ag and 7.5% PY extract was chosen to investigate its potential for use in wound dressing applications. The degrees of weight loss and water swelling of the electrospun CA/PY7.5/Ag fiber mat after immersion in a phosphate buffer solution (pH 7.4) at 37°C were examined in a range of 2-24 h, and found to increase with immersion time. The antioxidant activity of the fiber mat at the same period of immersion time was also studied, which corresponded with the trends of weight loss and water swelling. The antioxidant activity at 24 h of immersion was 68.3±9.2%. The CA/PY7.5/Ag fiber mat had no antibacterial activity against Escherichia coli but slightly inhibited the growth of Staphylococcus aureus. The fiber mat also possesses high hydrophilicity, as examined by the contact angle measurement. These results indicate that the CA/PY7.5/Ag fiber mat is a promising material for use as a topical transdermal patch or wound dressing.

Cigarette filter fibres as a source and sink of trace metals in coastal waters

Cellulose acetate fibres from cigarette filters represent a form of microplastic that has received little attention in the environment. In this study, a ground composite of spent, smoked filter material (FM) has been used to investigate the role of cellulose acetate fibres as a source and a sink of trace metals (Cd, Co, Cu, Ni, Pb and Zn) in coastal waters. FM suspended in river water and seawater and mixtures thereof representative of an estuarine gradient resulted in the leaching of pre-existent metals derived from the combustion of tobacco, with mean percentages of release ranging from about 40 for Pb to nearly 90 for Cd, Co and Zn. Addition of 40 μg L−1 of each metal to FM suspensions incubated for 48 h yielded mean partition coefficients (KDs) ranging from <10 L kg−1 for Co to > 100 L kg−1 for Cu, Pb and Zn, with Cu and Ni displaying a net increase in KD with increasing salinity. Adsorption is interpreted in terms of hydrophobic interactions between metal-organic complexes and the cellulose acetate surface, and in support of this assertion KDs exhibited a significant, positive relationship with published metal-humic acid binding constants. The findings of this study improve our understanding of the role of cellulosic microfibres more generally in transporting trace metals in aquatic systems.

Nanocomposite fibers based on cellulose acetate loaded with fullerene for cancer therapy: preparation, characterization and in-vitro evaluation

The current prevalence of cancerous diseases necessitates the exploration of materials that can effectively treat these conditions while minimizing the occurrence of adverse side effects. This study aims to identify materials with the potential to inhibit the metastasis of cancerous diseases within the human body while concurrently serving as therapeutic agents for their treatment. A novel approach was employed to enhance the anti-cancer properties of electrospun cellulose fibers by incorporating fullerene nanoparticles (NPs) into cellulose acetate (CA) fibers, resulting in a composite material called Fullerene@CA. This development aimed at utilizing the anti-cancer properties of fullerenes for potential therapeutic applications. This process has been demonstrated in vitro against various types of cancer, and it was found that Fullerene@CA nanocomposite fibers displayed robust anticancer activity. Cancer cells (Caco-2, MDA-MB 231, and HepG-2 cells) were inhibited by 0.3 and 0.5 mg.g−1 fullerene doses by 58.62–62.87%, 47.86–56.43%, and 48.60–57.73%, respectively. The tested cancer cells shrink and lose their spindle shape due to morphological changes. The investigation of the prepared nanocomposite reveals its impact on various genes, such as BCL2, NF-KB, p53, Bax, and p21, highlighting the therapeutic compounds' effectiveness. The experimental results demonstrated that the incorporation of NPs into CA fibers resulted in a significant improvement in their anti-cancer efficacy. Therefore, it is suggested that these modified fibers could be utilized as a novel therapeutic approach for the treatment and prevention of cancer metastasis.

Amine-functionalized MIL-101(Cr) fibers for direct air capture at cold temperatures using rapid temperature vacuum swing adsorption

Given that most of the world shows annual temperatures lower than 25 °C and some regions exhibit a large diurnal temperature difference in a single day, it is desirable to explore the CO2 sorption behavior of materials not only at ambient (25 °C) but also at cooler, “sub-ambient” conditions (defined here as < 25 °C). These cold temperatures may offer advantages for DAC such as higher gas adsorption capacities and lower absolute humidity, reducing concomitant water adsorption. Here, amine-functionalized MIL-101(Cr) fibers are evaluated at cold temperatures using rapid temperature vacuum swing adsorption (RTVSA). MIL-101(Cr)/cellulose acetate fibers loaded with macromolecular amines are evaluated as practical gas–solid contactors. As spun MIL-101(Cr) fibers show desirable properties for use as structured contactors such as high permeance and low pressure drop. Breakthrough and RTVSA experiments are conducted in the presence of humidity at sub-ambient temperatures to understand the CO2 adsorption and desorption behavior of the sorbent/contactor under conditions approaching practical operation. With optimized amine loading, the PEI-MIL-101(Cr) fibers give CO2 capacities comparable to the powder form of the sorbent, as well as sharp breakthrough curves at fast flow rates (1.4 m/s superficial velocity) suggesting the system is not limited by additional mass transfer resistances under the tested conditions. RTVSA shows fast desorption kinetics (14.4 mmol of CO2/g of fiber/h) at moderate desorption conditions, at 0.1 bar vacuum with temperatures below 80 °C. The entire cycle during RTVSA finishes in ∼ 25 min with ∼ 76 mol% CO2 purity as the product in this initial, modestly optimized study.

First assessment of anthropogenic particle ingestion in Pontellid copepods: Pontella mediterranea as a potential microplastic reservoir in the Neuston

Hyponeustonic species, living at the interface between the atmosphere and the oceans, comprise one of the most understudied and vast critical marine biotope, constantly exposed to high concentrations of anthropogenic contaminants and microplastic (MPs). Copepods of the Pontellidae family represent the primary components of this biotic assemblage worldwide, and their interaction with MPs is still unknown. We studied this interaction for the first time in Pontella mediterranea, assessing the ingestion of anthropogenic particles (APs) in 2793 individuals collected by manta trawl in the Northern Alboran Sea.We observed P. mediterranea abundances ranging from 41.67 to 1174.83 ind/m3, with a mean ingestion of 0.11 APs/ind, predominantly composed of MPs. These results confirm the low ingestion values observed for other copepod taxa. However, given its abundance, this species could retain an average of 45.15 and a maximum of 220 APs per m3 of seawater (APs/m3), mostly composed of cellulose acetate and cotton fibers. The abundances of APs were evaluated in surface (0–12 cm) and sub-surface waters (5 m depth) by combining manta trawl and Continuous Underway Fish Egg Sampler sampling. The AP abundances found (surface waters: 0.67 ± 1.04 APs/m3; subsurface waters: 3.85 ± 2.67 APs/m3) were consistent with those previously observed in the Mediterranean basin, confirming that the ingestion values observed in P. mediterranea are not due to a local accumulation of environmental MPs.Results highlight how this neustonic copepod could represent one of the largest reservoirs of APs within the upper layers of the oceans, representing an entry point for these particles within food webs. Considering the worldwide distribution and abundance of this family of copepods, the results are of environmental concern.

Sputtering deposition under limited adatom mobility: an effective method to prepare a SERS substrate based on Ag@ZnO composite deposited onto electrospun cellulose acetate fibers

Sputtering deposition under limited adatom mobility: an effective method to prepare a SERS substrate based on Ag@ZnO composite deposited onto electrospun cellulose acetate fibers

Single fibre coating of cellulose acetate fibres for hydrophilic modification using carboxymethylated starch

Hydrophilic bio-based and biodegradable fabrics and fibres can be an alternative to petroleum-based fabrics and fibres. Hydrophilic modifications of conventional textile structures by compositing can be introduced on a fabric as well as on a fibre level. Here, the coating of hydrophobic cellulose acetate multifilaments with carboxymethylated starch (CMS) pastes is reported. The CA fibres were drawn through starch preparations with varying degrees of substitution for coating. To ensure CMS anchorage, citric acid was added to cross-link the hydrophilic starch preparation itself and to the substrate. Cross-linking and CMS gel viscoelasticity were determined using a heated FT-IR stage and a rheometer respectively. The composites were also characterised for citric acid elution, as their degree of swelling in water vapour. As the amount of crosslinker increased, the gel viscoelasticity increased, but so did the citric acid elution in swelling media. Through several drying and swelling steps, the hydrophilic CMS structures lose their swelling ability. Coated fibres were also tested in a fine wash. The hydrophilic coating is depleted.An estimate of the chemical consumption for the production of such composites is given and compared with related approaches. As the chemical modification only affects the sheath, the chemical consumption can be reduced.