Cellulose Acetate Polymer Research Articles

Investigation of mixed matrix membranes of graphene and acid‐treated graphene fillers in cellulose acetate and polyetherimide polymers for CO2 separation from biogas

AbstractGas separation membranes are crucial for upgrading biogas by separating carbon dioxide (CO2) from biogas, thereby enhancing its calorific value and reducing greenhouse gas emissions. This study aims to improve CO2/CH4 separation using mixed‐matrix membranes (MMMs) by incorporating graphene (Gr) and acid‐treated graphene (AGr) fillers in a cellulose acetate (CA) polymer matrix. Similarly, polyetherimide (PEI) MMMs were also prepared with Gr and AGr fillers to draw a comparison. Various characterization techniques, including Fourier transform infrared spectroscopy, differential scanning calorimetry, field emission scanning electron microscopy, Raman spectroscopy, and X‐ray diffraction, were employed to investigate the structural and morphological properties of the membranes and fillers. Gas permeation tests using a model biogas mixture (40% CO2 and 60% CH4) revealed that the 0.1%AGr/CA membrane achieved the highest CO2 permeability of 43 Barrers, which is approximately 307% more than that of the pure CA membrane, and showed a CO2/CH4 selectivity of 14.80. The 0.5%Gr/PEI membrane demonstrated the best performance among PEI‐based MMMs, with a CO2 permeability of 17.48 Barrers and a CO2/CH4 selectivity of 8.96. These results indicate that the incorporation of Gr and AGr significantly enhances the gas separation performance over pure CA and PEI membranes.Highlights Graphene (G) and acid‐treated Gr‐based cellulose acetate (CA) and polyetherimide (PEI) mixed‐matrix membranes (MMMs) were fabricated. Model biogas was used for testing CO2 and CH4 gas permeation. The 0.1% AGr/CA MMM showed 307% higher CO2 permeability than pure CA. The 0.5% Gr/PEI MMM showed 435% higher CO2 permeabilit than pure PEI. Structural properties were confirmed by Fourier transform infrared spectroscopy, differential scanning calorimetry, field emission scanning electron microscopy, Raman, and X‐ray diffraction.

Investigating the influence of stress on UV-induced degradation in cellulose acetate: A comprehensive experimental characterization

Renewable and degradable polymers have emerged in everyday applications ranging from mundane eating utensils to high-tech medical devices. However, the current literature lacks a thorough experimental characterization of the mechanical behavior change due to degradation. In this work, we characterize the microscopic chemical changes due to photo-degradation and resulting stress effects on the mechanical behavior of cellulose acetate, a renewable and degradable polymer that is used in various consumer products. Specifically, we photo-degrade this polymer under (i) traction-free conditions and (ii) under applied stress. A key finding of this work is that upon photo-degradation, this material undergoes chain scission, which affects its mechanical properties and may be further affected by the applied stress.

Effect of Reaction Time and Solvent Ratio on the Acetylation of Isolated Cellulose Fiber from Tropical Water Hyacinth

Abstract Isolated cellulose fibers from water hyacinth were used to create cellulose acetate (CA) polymers. The cellulose was acetylated using an acetic acid and acetic anhydride reaction, with sulfuric acid acting as the catalyst. The degree of substitution (DS) of synthetic CA was examined, along with the effects of acetylation time and solvent ratio. The study indicated that the appropriate DS for CA was found to be 2.47 and the matching ideal operating parameters included a reaction duration of 16 hours, and a ratio of 4:1 between acetic acid and acetic anhydride at temperature of 50°C. The results of the study showed that the cellulose isolated from water hyacinth was successfully acetylated, which was supported by the existence of distinct peaks in the Fourier transform infrared (FTIR) spectra. This suggests that the process of acetylating the isolated cellulose fibers is a straight-forward process that can be employed to create a cost-efficient and environmentally friendly CA. This CA has the potential to cost-effectively and sustainably replace expensive raw materials derived from fossil fuels in the polymer industry.

Electrospinning of cellulose nanocrystals; procedure and optimization

Cellulose nanocrystals (CNCs) and cellulose microfibrils (CMFs) are promising materials with the potential to significantly enhance the mechanical properties of electrospun nanofibers. However, the crucial aspect of optimizing their integration into these nanofibers remains a challenge. In this work, we present a method to prepare and electrospin a cellulosic solution, aiming to overcome the existing challenges and realize the optimized incorporation of CNCs into nanofibers. The solution parameters of electrospinning were explored using a combined experimental and simulation (molecular dynamics) approach. Experimental results emphasize the impact of polymer solution concentration on fiber morphology, reinforcing the need for further optimization. Simulations highlight the intricate factors, including the molecular weight of cellulose acetate (CA) polymer chains, electrostatic fields, and humidity, that impact the alignment of CNCs and CMFs. Furthermore, efforts were made to study CNCs/CMFs alignment rate and quality optimization. It is predicted that pure CNCs benefit more from electrostatic alignment, while lower molecular weight CA enables better CNC/CMF alignment.

Adsorptive membrane separation for eco-friendly decontamination of chlorpyrifos via biochar-impregnated cellulose acetate mixed matrix membrane.

In this work, the phase inversion approach is used to synthesize a blended mixed matrix membrane from cellulose acetate polymer and sugarcane bagasse biochar. The experiments were carried out to estimate the extent of chlorpyrifos (CPS) pesticide removal. The results showed that the removal rate was more than 99% in making the filtered water suitable enough for domestic use. The physical and functional characteristics of the membranes, such as permeability, and contact angle were identified. The changes in the membrane characteristics were observed using scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction both before and after the experimental trials. Experiments were conducted to assess not only the rejection characteristics of CPS, as a function feed concentration, but also the effect co-ions on the rejection used to analyze the composition both before and after filtration. The effects of initial CPS concentration, biochar loading, and co-ions on the membrane were investigated. The membranes showed contact angles between 70° and 97° and a permeability between 0.25 × 1010 m Pa-1 s-1 and 0.31 × 1010 m Pa-1 s-1. The effective removal of CPS from the contaminated aqueous stream was attributed to a combination of adsorptive uptake and membrane-based separation. CPS was found to get adsorbed onto the membrane matrix through an intraparticle diffusion mechanism along with an irreversible monolayer adsorption. The membrane-solute adsorptive interaction was represented by Langmuir isotherm and intraparticle diffusion models with a maximum adsorption capacity of 192.3 mg g-1. The findings indicated the efficacy of biochar-cellulose acetate mixed matrix membrane for sustainable and eco-friendly treatment of chlorpyrifoscontaminated water.

Synthesis and luminescent properties of cellulose acetate butyrate films doped with europium complex Eu(TTA)3 for optical thermometry

In this work, the luminescent β-diketonate europium complex, Eu(TTA)3, was incorporated into the polymer cellulose acetate butyrate in different concentrations in the form of composite films. The photoluminescence analysis showed that the composites improved the internal transition of the europium ion, 5D0 → 7F2, mainly responsible for the emission of red light from the complex, by providing a highly asymmetric chemical environment around the europium ion and by reducing non-radiative decays. The composite matrix also contributed to the quantum efficiency of the luminescence, reaching 38 %, by reducing the excited state deactivation rates. The luminescence lifetime of the composite linearly decayed with increasing temperature, while the luminescence intensity displayed an exponential decrease by increasing temperature, both behaviors proved to be appropriate for use in optical thermometry. The analysis of Raman spectra, Judd-Ofelt parameters, decay rates, and lifetime showed that the characteristics of the isolated complex were mostly maintained after being added to the polymeric matrix.

OSMOTIC DRUG DELIVERY SYSTEM OF NICORANDIL: DESIGN AND EVALUATION

Objective: The purpose of the current research was to design a nicorandil formulation with controlled drug release using the principles of osmotic pump technology. Nicorandil is a biopharmaceutical classification system (BCS) class 3 drug, having a shorter plasma elimination half-life and bioavailability of 75 to 80%. Methods: The elementary osmotic pump (EOP) was prepared by coating a cellulose acetate polymer on the prepared core tablet. A 24-factorial design was applied to optimize the parameters for the osmotic tablet. A surface orifice was drilled. Results: Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) results showed that there was no interaction between drugs and excipients. A 24-factorial design was applied to optimize the parameters for the elementary osmotic pump. The optimized batch was characterized for in vitro drug release studies, and the effects of pH, osmotic pressure, and agitation intensity were analyzed. All the batches showed a drug release ranging from 90.48% to 98.78% after 12 hours. There was no change in the drug release pattern at different pHs and agitation intensities. The drug release was found to decrease with the increasing osmotic pressure of the dissolution medium. The results showed that the amounts of sodium chloride and mannitol were positively affecting the drug release, while the plasticizers PEG400 and DBP were not critical. Scanning electron microscopic studies (SEM) showed the integrity and surface morphology of the coating membrane before and after dissolution. The prepared EOP was found to deliver nicorandil at zero-order for up to 12 hours. Conclusion: Nicorandil was developed successfully as a controlled drug delivery during a 12-hour period, with variables optimized by the use of a 24-factorial design.

A preliminary study on 3D printing feedstock derived from cellulose recovered from cigarette butts

AbstractIn this work, we describe the recovery of cellulose acetate (r-CA) polymer from waste cigarette butts (CBs) and their subsequent conversion into feedstock for 3D printing technology. The extraction process for CBs includes two stages: initial washes in water, followed by additional washes in ethanol. A final step involves a dissolution and reprecipitation process, resulting in the creation of a fine powder. The recovery polymer has been analysed and compared to commercial cellulose acetate (p-CA) and unsmoked cigarette filter (u-CA) to assess its purity and examine alterations in its physicochemical properties. The CA powder has also been plasticized with different biocompatible plasticizers to improve the mechanical properties of the CA. We analyze the rheological properties to identify the suitable composition as feedstock for 3D printing.

Boosting the recyclability of flame-made Bi2O3 via insitu immobilization in cellulose acetate nanofibers for efficient photocatalytic degradation of rhodamine B dye

Flame spray pyrolysis is a novel fast-process for producing functional metal oxides. However, these functional nanomaterials are challenged with poor recyclability in water treatment from pollutants such as dyes. Herein, Bi2O3 nanoparticles were produced by flame spray pyrolysis and spun together with eco-friendly cellulose acetate polymer into nanofiber membrane via electrospinning technique. The results reveal that cellulose acetate (CA) has good interaction with the particles, leading to reduced band gap, retardation of fast recombination of carriers and good electron transportation on the surface of the nanofiber membrane. The Bi2O3/CA nanofiber membrane records similar photocatalytic performance to that of flame-made Bi2O3 nanoparticles, that is about 95% dye degradation at 90 min, which was far better than CA and Bi2O3/polyacrylonitrile nanofiber membranes. The electron spin resonance test and free radical scavenger test reveal that abundant hydroxyl radicals serve as the most active species that enhance photocatalytic degradation of dye on Bi2O3/CA nanofiber membrane. The flexible Bi2O3/CA nanofiber membrane also demonstrates easy recyclability after several runs with no significant decline in performance. This study pins the effectiveness of using eco-friendly cellulose acetate in obtaining inorganic-organic composite to concurrently achieve good photocatalytic performance and recyclability.

Visible‐Light‐Active Electrospun Membranes Based on Cobalt‐Doped ZnO Nanohybrids: Applications for Food Packaging

AbstractA cellulose acetate electrospun membrane based on Cobalt doped ZnO (Co‐ZnO) was developed. The synthesis of pure zinc oxide nanoparticles (NPs) and cobalt‐zinc oxide nanorods with varying cobalt‐to‐zinc atomic ratios of 5 %, 10 %, 15 %, and 20 % was carried out, using the co‐precipitation method. The successful incorporation of cobalt into ZnO was confirmed by using the techniques of Powder X‐ray Diffraction (PXRD), X‐ray Photoelectron Spectroscopy (XPS), and Energy Dispersive X‐ray Spectroscopy (EDX). Scanning Electron Microscopy (SEM) studies denoted the change in shape from spherical to rod‐shaped upon doping Co. A red shift was observed in band gap energies from 3.26‐3.01 eV upon increasing the Co concentration. The photocatalytic activity was evaluated, using methylene blue under sunlight and a 50 W LED lamp. The most effective photocatalyst observed in this study was a composition consisting of 15 % Co‐ZnO. When exposed to sunshine, this photocatalyst demonstrated a degradation rate of 40 % over a one‐hour period. Similarly, when subjected to a lamp, the degradation rate was found to be 24 % over the same duration. A nanofiber membrane was produced by incorporating Co‐ZnO at a concentration of 15 % (w/w) into the cellulose acetate (CA) polymer matrix by the electrospinning technique. The created CA nanofiber mat with Co‐ZnO was employed to extend the shelf life of strawberries up to 18 days along with the reduced pH increase and lower reduction of weight, firmness, and titratable acidity.

Porous Microneedles Through Direct Ink Drawing with Nanocomposite Inks for Transdermal Collection of Interstitial Fluid.

Interstitial fluid (ISF) is an attractive alternative to regular blood sampling for health checks and disease diagnosis. Porous microneedles (MNs) are well suited for collecting ISF in a minimally invasive manner. However, traditional methods of molding MNs from microfabricated templates involve prohibitive fabrication costs and fixed designs. To overcome these limitations, this study presents a facile and economical additive manufacturing approach to create porous MNs. Compared to traditional layerwise build sequences, direct ink drawing with nanocomposite inks can define sharp MNs with tailored shapes and achieve vastly improved fabrication efficiency. The key to this fabrication strategy is the yield-stress fluid ink that is easily formulated by dispersing silica nanoparticles into the cellulose acetate polymer solution. As-printed MNs are solidified into interconnected porous microstructure inside a coagulation bath of deionized water. The resulting MNs exhibit high mechanical strength and high porosity. This approach also allows porous MNs to be easily integrated on various substrates. In particular, MNs on filter paper substrates are highly flexible to rapidly collect ISF on non-flat skin sites. The extracted ISF is used for quantitative analysis of biomarkers, including glucose, = calcium ions, and calcium ions. Overall, the developments allow facile fabrication of porous MNs for transdermal diagnosis and therapy.

Preparation and characterization of Fe-ZnO cellulose-based nanofiber mats with self-sterilizing photocatalytic activity to enhance antibacterial applications under visible light.

Bacterial infections and antibiotic resistance have posed a severe threat to public health in recent years. One emerging and promising approach to this issue is the photocatalytic sterilization of nanohybrids. By utilizing ZnO photocatalytic sterilization, the drawbacks of conventional antibacterial treatments can be efficiently addressed. This study examines the enhanced photocatalytic sterilizing effectiveness of Fe-doped ZnO nanoparticles (Fe-ZnO nanohybrids) incorporated into polymer membranes that are active in visible light. Using the co-precipitation procedure, Fe-ZnO nanohybrids (Fe x Zn100-x O) have been generated using a range of dopant ratios (x = 0, 3, 5, 7, and 10) and characterized. The ability to scavenge free radicals was assessed and the IC50 value was calculated using the DPPH test at different catalytic concentrations. PXRD patterns showed a hexagonal wurtzite structure, which indicated that the particle size of the nanohybrid decreased as the dopant concentration rose. It was demonstrated by UV-vis diffuse reflectance experiments that the band gap of the nanohybrid decreased (redshifted) with Fe doping. The photocatalytic activity under sunlight increased steadily to 87% after Fe was added as a dopant. The Fe 5%-ZnO nanohybrid exhibited the lowest IC50 value of 81.44 μg mL-1 compared to ZnO, indicating the highest radical scavenging activity and the best antimicrobial activity. The Fe 5%-ZnO nanohybrid, which is proven to have the best photocatalytic sterilization activity, was then incorporated into a cellulose acetate polymer membrane by electrospinning. Disc diffusion assay confirmed the highest antimicrobial activity of the Fe 5%-ZnO nanohybrid incorporated electrospun membrane against Staphylococcus aureus (ATCC 25923), Streptococcus pneumoniae (ATCC 49619), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), and Candida albicans (ATCC 10231) under visible light. As a result, Fe 5%-ZnO nanofiber membranes have the potential to be employed as self-sterilizing materials in healthcare settings.

CuS/Cellulose acetate nanofiber composite: A study on adsorption and photocatalytic activity for water remediation

This paper addresses the pressing concern of environmental deterioration by investigating innovative solutions for tackling water pollution in aquatic ecosystems. Various hazardous pollutants, such as dyes, pharmaceuticals, heavy metals, and pesticides, pose significant threats to both the environment and human health. To combat these issues, in this work we explored the synthesis of composite nanofibers using copper sulfide (CuS) nanoparticles and cellulose acetate (AC) polymer matrix through a gas-liquid sulfurization process. The resulting nanocomposites were used to fabricate nanofibers by the electrospinning technique. The morphological analyses revealed a transition from ribbon-like structures to cylindrical forms as nanoparticle concentration was increased. Chemical analysis confirmed the presence of CuS nanoparticles within the composite nanofibers. XRD studies indicated a covellite crystal structure of the CuS nanoparticles. TGA analysis revealed a coordination complex formation between nanoparticles and dimethylformamide. Optical properties showed variations in band gap energies, from 1.76 to 1.9 eV, as nanoparticle concentration changed. Photocatalysis studies demonstrated that the composite nanofibers exhibited enhanced adsorption and degradation of methylene blue dye under solar irradiation. Overall, this study contributes to understanding the potential application of CuS/AC composite nanofibers for environmental remediation.

Iron(III) based Metal-Organic Frameworks in cellulose acetate film preservation: Fundamental aspects and first application

Low-temperature storage to slow down degradation is accepted by the film conservation community. Still, this solution prohibits public access, is price-sensitive, has high energy costs, and there are concerns about their effects on the physical stability and material lifetime. In this research, a smart solution is developed based on the selective capture of acetic acid produced by the cellulose acetate polymer. This innovative approach is based on Metal-Organic Frameworks (MOFs) for acetic acid adsorption, specifically a highly selective porous iron(III) based MOF, MIL-100(Fe), which was synthesized using a green approach. The stability of MIL-100(Fe), under acetic acid exposure, was demonstrated by accelerated aging experiments, with no noticeable changes in crystallinity and/or porosity as deduced from powder X-ray diffraction analysis, infrared spectroscopy, thermogravimetric analysis, nitrogen porosimetry, and electron microscopy. Compatibility tests with the artefacts were performed to prove the safety of the MIL-100(Fe) to the artefacts. A field application in a demonstration prototype (smart box) was performed at Institut Valencià de Cultura. A recently developed hybrid model provided recommendations on the quantity of adsorbents to use in the smart box. Good agreement was observed between the model predictions and the in-field experimental results, which validated the model application. The model predicted that the new adsorbent (5% of the film's weight, replaced every 10 years, at 16°C or 22°C) extends the film's lifetime equivalently to cold storage (5°C). Finally, environmental impact assessment and life cycle analysis were performed to compare the two preservation approaches. The new approach based on this Fe-MOF yielded an average reduction of carbon footprint related to movie film preservation of about 50% considering the current European Union (EU) energy mix and about 40% considering the 2030 EU energy mix (where a transition towards renewable energy is expected). The proposed innovative technology represents a robust solution towards efficient and more sustainable film preservation while significantly contributing to moving toward climate transition objectives in the culture heritage sector.

Fabrication of composite membrane with microcrystalline cellulose from lignocellulosic biomass as filler on cellulose acetate based membrane for water containing methylene blue treatment

A composite membrane based on cellulose acetate polymer with microcrystalline cellulose (MCC) based filler from lignocellulosic biomass is one of the right solutions to reduce methylene blue (MB) levels in water. MCC has been successfully isolated from water hyacinth, sengon wood, and kapok fiber with an alkalization method. The three MCCs have shown X-ray and FTIR diffraction patterns with characteristic peaks from cellulose and are stable up to 317 °C. Cellulose acetate (CA)/MCC membranes have been prepared using the phase inversion method and characterized by FTIR, tensile strength, contact angle, SEM, and porosity. The characterization results show that the addition of MCC can increase the tensile strength (3.05 N·mm-2), hydrophilicity (52°), and porosity (88 %). The CA/MCC membrane performed better than the neat membrane in separating MB. The composite membrane with MCC from kapok fiber showed optimum performance with increased flux and MB rejection up to 84 L·m−2·h−1 and 99 %, respectively.

How Do 3D Printing Parameters Affect the Dielectric and Mechanical Performance of Polylactic Acid–Cellulose Acetate Polymer Blends?

Three-dimensional printing is a prototyping technique that is widely used in various fields, such as the electrical sector, to produce specific dielectric objects. Our study explores the mechanical and dielectric behavior of polylactic acid (PLA) and plasticized cellulose acetate (CA) blends manufactured via Fused Filament Fabrication (FFF). A preliminary optimization of 3D printing parameters showed that a print speed of 30 mm·s−1 and a print temperature of 215 °C provided the best compromise between print quality and processing time. The dielectric properties were very sensitive to the three main parameters (CA content WCA, infill ratio, and layer thickness). A Taguchi L9 3^3 experimental design revealed that the infill ratio and WCA were the main parameters influencing dielectric properties. Increasing the infill ratio and WCA increased the dielectric constant ε′ and electrical conductivity σAC. It would, therefore, be possible to promote the integration of CA in the dielectric domain through 3D printing while counterbalancing its greater polarity by reducing the infill ratio. The dielectric findings are promising for an electrical insulation application. Furthermore, the mechanical findings obtained through dynamic mechanical analysis are discussed.

Cellulosic Nanofibers Utilizing a Silicone Elastomeric Core to Form Stretchable Paper

AbstractPaper, an inexpensive material with natural biocompatibility, non‐toxicity, and biodegradability, allows for affordable and cost‐effective substrates for unconventional advanced electronics, often called papertronics. On the other hand, polymeric elastomers have shown to be an excellent success for substrates of soft bioelectronics, providing stretchability in skin wearable technology for continuous sensing applications. Although both materials hold their unique advantageous characteristics, merging both material properties into a single electronic substrate reimagines paper‐based bioelectronics for wearable and patchable applications in biosensing, energy generation and storage, soft actuators, and more. Here, a breathable, light‐weighted, biocompatible engineered stretchable paper is reported via coaxial nonwoven microfibers for unconventional bioelectronic substrates. The stretchable papers allow intimate bioconformability without adhesive through coaxial electrospinning of a cellulose acetate polymer (sheath) and a silicone elastomer (core). The fabricated cellulose‐silicone fibers exhibit a greater percent strain than commercially available paper while retaining hydrophilicity, biocompatibility, combustibility, disposable, and other natural characteristics of paper. Moreover, the nonwoven stretchable cellulose‐silicone fibrous mat can adapt conventional printing and fabrication process for paper‐based electronics, an essential aspect of advanced bioelectronic manufacturing.

Electrospun Mutualism–Inspired CA/CMA/PHMB ultrafine bimodal nanofibrous membrane for High–Performance, Antibacterial, and Mosquito–Repellent air filtration

Composite bio–based multifunctional air filtration is a great challenge and development trend for personal protection. This work was inspired by nature mutualism to produce bio–based and essential oil loaded nanofibrous membrane with multiple functions of high–performance, antibacterial, and mosquito–repellent. The cinnamaldehyde (CMA) and poly(hexamethylene biguanide) (PHMB) were introduced into the cellulose acetate (CA) polymer system to achieve functionalization, and then the CA/CMA/PHMB ultrafine bimodal nanofibrous membrane was prepared through one–step electrospinning. Compared to eugenol, the CMA contributed to the refinement of fiber and minimized the reduction of mechanical properties, thermal stability, and hydrophobicity. On the other hand, the PHMB enhanced jet splitting and synergistically improved antibacterial ability with CMA. The filtration efficiency for PM0.3, the pressure drop, and the quality factor were 99.78%, 59.5 Pa, and 0.1028 Pa−1, respectively. The bacteriostatic rates against Escherichia coli and Staphylococcus aureus, and the mosquito–repellent rate were 99.65%, 99.99%, and 92.7%, respectively. Lastly, the batch preparation of this solution was explored, which contributed to commercialization. This work provides a novel and simple approach to efficiently fabricate multifunctional high–performance air filter, which will promote the development of bio–based and sustainable air filter.

Digital ink‐jet printing of regenerated cellulose nanofibrous mats with reactive inks

AbstractThe versatility of nanofibres enables them to be used for various technological applications such as filtration, biomedicine and healthcare, composites, protective and functional textiles. Recently, in addition to the functional properties of electrospun nanofibrous mats, their aesthetic properties have been explored. Herein, attempts have been made to develop digital ink‐jet printing of regenerated cellulose nanofibrous mats with reactive inks. First, a cellulose acetate polymer was created to fabricate electrospun cellulose acetate nanofibrous mats, which were then converted into regenerated cellulose nanofibrous mats through deacetylation. Next, the cellulose nanofibrous mats were treated with an alkaline solution then coloured with four (cyan, magenta, yellow and black) commercially available reactive inks by a digital ink‐jet printing method using a piezoelectric digital ink‐jet printer. Various parameters were investigated, including the optimal concentration of the pretreatment agents, fixation temperature and time, colour yield and the absorbency of the electrospun nanofibrous mats. The digital ink‐jet printed cellulose nanofibrous mats exhibited excellent colour yield and colour fastness properties. Morphological analysis through scanning electron microscopy and chemical analysis through Fourier Transform–infrared were also carried out.

Graphene-grafted bimetallic MOF membranes for hazardous & toxic contaminants treatment

Development of membrane with improved carbon dioxide (CO2) gas separation capability is a significant challenge. However, the fabrication of membrane that efficiently separate and purification CO2-containing gases has been the focus of global attention. Cellulose Acetate (CA) has robust reinforcing characteristics when incorporated within a suitable polymer matrix. This work focus on the synthesis of novel mixed matrix membranes (MMMs) by introducing Graphene-grafted bimetallic MOFs in Cellulose Acetate polymer. The graphene-grafted bimetallic MOF (GG-BM MOFs) was prepared by a hydrothermal technique. Whereas, the solution casting approach used to fabricate membranes. The 1–5 wt% of GG-BM MOFs incorporated into the CA matrix. The mechanical, hydrophilicity and adsorption characteristics of fabricated MMMs were investigated. The crystallinity of MMM enhanced after the addition of GG-BM MOFs. In addition, the mechanical characteristics of MMMs were improved with the incorporation of GG-BM MOFs inside the polymer matrix. Maximum stress and strain was obtained for 2 wt% MMM (36.4 N/mm2 and 11% respectively). The CO2 adsorption performance was evaluated at 10 bar and 45 °C. The FTIR results represent insignificant bond shifting with the addition GG-BM MOFs at these conditions. The overall results showed that MMMs containing 2 wt% GG-BM MOFs have good adsorption properties for CO2 i.e 3.15 wt% of CO2. The MMMs have shown a decrease in the mechanical properties and CO2 adsorption at the higher GG-BM MOFs loading due to the presence of agglomeration which was confirmed through SEM. Thus, the addition of GG-BM MOFs in the CA matrix positively altered the physicochemical characteristics of the resulting MMMs, which could assist them in achieving remarkable CO2 adsorption at 2 wt%.