Cellulose Solution Research Articles

Estimation of the performance of different pumps using non-Newtonian fluids in various operating conditions with artificial neural network

The performance of three centrifugal pumps designed to operate at a rotational speed of 151.84 rad/s and flow rates of 1, 25, and 45 kg/s is being investigated for both water and non-Newtonian fluids at various rotational speeds and flow rates. The analyses are being conducted experimentally and numerically within the flow rate range of 0.25–55 kg/s and rotational speed values between 52.36 and 151.84 rad/s. Additionally, artificial neural networks (ANN) trained using experimental pump performance data are being tested with experimental and numerical values obtained at a new rotational speed of 130.9 rad/s. The non-Newtonian fluids being tested include CMC 0.2% and CMC 0.4%, comprising carboxy methyl cellulose (CMC) solution and water. The results indicate that the pump's performance when handling non-Newtonian fluids is significantly influenced by the pump's geometry, rotational speed, and flow rate. In design parameters, the head obtained with 0.2% CMC for pump 1 is 3.3% greater than that in water. For pump 2, the highest head is in water according to design parameters. Pump 3 exhibits the highest head at a CMC of 0.4 in design parameters, and this value is 0.81% higher than the value with water. Experimental and numerical results demonstrate good agreement, especially in design parameters. The head obtained from numerical analyses with the RNG k–ε turbulence model for pumps 1, 2, and 3 at design parameters is 3, 10, and 9.83 m, respectively. The corresponding experimental heads are 3, 10, and 9.84 m, respectively. However, discrepancies between these results increase with higher flow rates and the use of non-Newtonian fluids. The compatibility of ANN results with experimental results is better than with numerical results, particularly at higher flow rates than the design condition. Pump performance values estimated by ANNs are 2% lower than the experimental results. This study provides comprehensive experimental data on the use of non-Newtonian fluids in different centrifugal pumps, and it also offers important guidance for future research by comparing ANN and computational fluid dynamics.

Small-angle neutron scattering from cellulose solutions in phosphoric acid at different water content

Cellulose from biomass is an abundant and renewable alternative source for chemicals and fuels, yet its utilization by chemical or biological process requires pre-treatment in order to release the macromolecules from their tightly packed crystal structure. Phosphoric acid (PA) has been known for many years to be an efficient solvent for crystalline cellulose. It is also established that a certain quantity of water content in PA is required for efficient pretreatment. This study uses small-angle neutron scattering (SANS) measurements to evaluate cellulose dissolution in deuterated phosphoric acid (dPA), at different wt% dPA between 78 and 97 % (different D2O content). The SANS method is useful for this purpose due to the availability of deuterated dPA, its contrast in scattering length density towards cellulose, and its low incoherent scattering cross-section. The results indicate that most of the cellulose in 2 wt% solution is dissolved in PA as individual chains, at acid content of 81–94 wt% PA. Structural differences of the dissolved cellulose in PA of the various water compositions in this range are insignificant. At 78 % dPA the cellulose crystal still seem to be disrupted, yet the structure can be modeled as mass-surface fractals of small fibrils with irregular surface, possibly due to dissolved chain segments, which are aggregated as mass fractals of rods. At 97 % dPA evidence for a small content of undissolved fibrils is noted.

Liquid Flow Patterns and Particle Settling Velocity in a Taylor-Couette Cell Using Particle Image Velocimetry and Particle Tracking Velocimetry

Summary Controlling the downhole pressure is an important parameter for successful and safe drilling operations. Several types of weighting agents (i.e., high-density particles), traditionally barite particles, are added to maintain the desired density of the drilling fluid (DF). The DF density is an important design parameter for preventing multiple drilling complications. These issues are caused by the settling of the dense particles, an undesired phenomenon also referred to as sagging. Therefore, there is a need to understand the settling characteristics of heavy particles in such scenarios. To this end, simultaneous measurements of liquid phase flow patterns and particle settling velocities have been conducted in a Taylor-Couette (TC) cell with a rotating inner cylinder and stationary outer cylinder separated by an annular gap of 9.0 mm. Liquid flow patterns and particle settling velocities have been measured using particle image velocimetry (PIV) and particle tracking velocimetry (PTV) techniques, respectively. Experiments have been performed by varying the rotational speed of the inner cylinder up to 200 rev/min, which is used in normal drilling operations. Spherical particles with diameters of 3.0 mm or 4.0 mm and densities between 1.2 g/cm3 and 3.95 g/cm3 were used. The liquid phases studied included deionized (DI) water and mineral oil, which are the basic components of a non-Newtonian DF with a shear-thinning viscosity. The DF is a mud-like emulsion of opaque appearance, which impedes the ability to observe the liquid flow field and particle settling in the TC cell. To address this issue, a solution of carboxymethyl cellulose (CMC) with a 6% weight concentration in DI water was used. This non-Newtonian solution displays shear-thinning rheological behavior and was used as a transparent alternative to the opaque DF. For water, PIV results have shown wavy vortex flow (WVF) to turbulent Taylor vortex flow (TTVF), which agrees with the flow patterns reported in the literature. For mineral oil, circular Couette flow (CCF) was observed at up to 100 rev/min and vortex formation at 200 rev/min. For CMC, no vortex formation was observed up to 200 rev/min, only CCF. The settling velocities for all particles in water matched with the particle settling velocities predicted using the Basset-Boussinesq-Oseen (BBO) equation of motion. For mineral oil and CMC, the results did not match well with the predicted settling velocities, especially for heavy particles due possibly to the radial particle migration and interactions with the outer cylinder wall.

Beyond waste: Transforming wheat straw into oxygen and UV‐resistant cellulose films

AbstractRegenerated cellulose membrane is a biomaterial obtained by activating, dissolving, solidifying, and regenerating cellulose powder using solvents of different polarities. It has the characteristics of high oxygen resistance and high strength. However, its low water vapor barrier and single function limit its application. In order to improve the water resistance of regenerated cellulose membranes and endow them with UV resistance, lignin was extracted from waste wheat straw using formic acid method. The extracted formic acid lignin (FAL) was added to the cellulose solution to prepare a series of regenerated lignocellulosic membranes (RC‐FAL) with different lignin contents. The results indicate that lignin can not only improve the water vapor barrier, tensile strength, and water resistance of the film, but also enhance the oxygen barrier and UV absorption of the film. Compared with pure cellulose film, the contact angle of lignocellulose film can be increased by 66.2%, the UV absorption rate can reach 100%, and the oxygen transmission coefficient has no significant effect. In this paper, a new kind of biological packaging material with high oxygen resistance, strong ultraviolet absorption, and water resistance was prepared by recycling waste wheat straw, it has a broad application prospect in the industrial production of packaging materials.

Hyperuricemia Induces Reproductive Damage in Male Rats through Zinc Homeostasis Imbalance and Oxidative Stress

Studies have reported the adverse effects of hyperuricemia on male reproduction, but the mechanism is still unclear. The purpose of this study is to explore the mechanism of hyperuricemia on reproductive system damage in male rats. The rats were divided into a control group and a model group. Rats were given hypoxanthine and potassium oxonate dissolved in 0.5% (w/v) sodium carboxymethyl cellulose solution to induce the hyperuricemia (HUA) model. After 6 weeks, the blood, testis, and epididymis tissues of the anesthetized rats were collected for further experiments and analysis. Compared with the control rats, the serum uric acid of HUA rats was significantly increased, and the serum testosterone, sperm count, and motility were significantly decreased. The protein expression of testosterone-related molecules CYP11A1, 3β-HSD, and StAR was downregulated in the testis of HUA rats. The protein expression of blood–testis barrier (BTB) related molecules ZO-1 and Connexin43 was downregulated in the testis of HUA rats. Compared with the control group, the zinc content and zinc-containing enzymes (ALP and LDH) were decreased, and the mRNA and protein expression of zinc transporters (ZnT4 and ZIP7) were downregulated in the testis of HUA rats. Furthermore, the level of MDA increased and the activities of CAT, GSH-PX, and SOD decreased in the testicular tissue of HUA rats. The PI3K/AKT/mTOR pathway in the testis of HUA rats was activated. However, there was no significant change in the protein expression of autophagy associated molecules LC3, Beclin1, and ATG5 in the testis of HUA rats. Thus, the conclusion is that hyperuricemia can lead to the destruction of BTB, impaired testosterone synthesis, and decreased sperm count and motility in male rats, mainly by inducing zinc homeostasis imbalance and oxidative stress, rather than autophagy.

Design and characterization of β-tricalcium phosphate-based self-passivating coatings on magnesium alloys.

Background: Magnesium alloys degrade rapidly in salt solutions, which limits their use without passivating treatments. AZ31 alloy is particularly promising for implant applications owing to its biodegradability and mechanical properties, necessitating effective corrosion-resistant coatings. Aim: In this study, a self-passivating reactive coating was designed and evaluated for AZ31 magnesium alloy plates using β-tricalcium phosphate (TCP) to enhance corrosion resistance and biocompatibility. Methods: Solutions of TCP, trisodium citrate, magnesium nitrate, hydroxyethyl cellulose (HEC), and sodium chloride were used to dip-coat AZ31 plates. The coated samples were immersed in 3.5 wt% NaCl solution. Phase evolution was analysed using gravimetry, X-ray diffraction (XRD), energy-dispersive X-ray (EDX) spectroscopy, and scanning electron microscopy (SEM). The biological response of the coated samples was evaluated through MTT and resazurin assays. Results: The coating formed a stable TCP/HEC layer that gradually dissolved over two weeks, converting the surface to magnesium hydroxide, magnesium oxychloride, and magnesium phosphate phases. The formation of brucite, responsible for passivation in the long term, was observed. The coating effectively prevented excessive magnesium oxychloride formation and stabilised magnesium hydroxide after one week. Biological characterization indicated that the coating on AZ31 is safe on the Saos-2 and L929 cell lines. Conclusion: The TCP-based coating enhances the corrosion resistance of AZ31 alloy in salt solutions, promoting passivating phases and limiting corrosive products, thereby ameliorating biocompatibility issues. This coating demonstrates substantial potential for extending the longevity and functionality of magnesium alloy implants.

High-throughput viscoelastic characterization of cells in hyperbolic microchannels.

Extensive research has demonstrated the potential of cell viscoelastic properties as intrinsic indicators of cell state, functionality, and disease. For this, several microfluidic techniques have been developed to measure cell viscoelasticity with high-throughput. However, current microchannel designs introduce complex stress distributions on cells, leading to inaccuracies in determining the stress-strain relationship and, consequently, the viscoelastic properties. Here, we introduce a novel approach using hyperbolic microchannels that enable precise measurements under a constant extensional stress and offer a straightforward stress-strain relationship, while operating at a measurement rate of up to 100 cells per second. We quantified the stresses acting in the channels using mechanical calibration particles made from polyacrylamide (PAAm) and found that the measurement buffer, a solution of methyl cellulose and phosphate buffered saline, shows strain-thickening following a power law up to 200 s-1. By measuring oil droplets with varying viscosities, we successfully detected changes in the relaxation times of the droplets and our approach could be used to get the interfacial tension and viscosity of liquid-liquid droplet systems from the same measurement. We further applied this methodology to PAAm microgel beads, demonstrating the accurate recovery of Young's moduli and the near-ideal elastic behavior of the beads. To explore the influence of altered cell viscoelasticity, we treated HL60 human leukemia cells with latrunculin B and nocodazole, resulting in clear changes in cell stiffness while relaxation times were only minimally affected. In conclusion, our approach offers a streamlined and time-efficient solution for assessing the viscoelastic properties of large cell populations and other microscale soft particles.

Effect of carboxymethyl cellulose, icodextrin and hyaluronic acid solutions on postoperative intraabdominal adhesion formation in rabbits and the role of cytokines in intraabdominal adhesion formation

In this study, the aim was to investigate the effects of 1% CMC, 4% ICO and 0.4% HA solutions in preventing postoperative IAs and their contribution to peritoneal wound healing, as well as the relationship of cytokines with the formation of postoperative IAs in rabbits. The material of the study consisted of 32 healthy rabbits. Rabbits underwent median laparotomy following general anesthesia. Serosal abraded was created at the antimesenteric border of the cecum. Next, a 3 × 2 cm peritoneum was excised on the right abdominal wall and the defect was closed using with a 2/0 silk suture. The rabbits were randomly assigned to either of the following four treatment groups: CNT (0.9% NaCl), ICO (4% icodextrin), HA (0.4% hyaluronic acid) and CMC (1% carboxymethyl cellulose). Both cecum and peritoneal surfaces were treated with 20 ml each of treatment solutions. On the 7th postoperative day, the rabbits were euthanized with a lethal dose of sodium pentobarbital and the degree of adhesion was evaluated. Samples taken from the peritoneal defect were examined histopathologically and tissue hydroxyproline levels were measured. Serum TNF-α, IL-1 and IL-6 levels were measured from blood samples taken before the surgery and at 1, 6, 24 and 48 hours after the surgery. It was observed that the adhesion grade in the HA group (p < 0.05) and CMC group (p < 0.01) was significantly lower than the control group. Although peritoneal tissue hydroxyproline levels were lower in the other groups compared to the control group, they were not statistically significant (p > 0.05). In rabbits with adhesion formation, it was determined that TNF-α levels increased at the 6th postoperative hour (p < 0.05), and IL-6 levels increased at the 6th, 24th and 48th postoperative hours (p < 0.001) compared to preoperative. In this study, treating tissues with 0.4% HA and 1% CMC solutions suppressed peritoneal inflammation, and this resulted in an increase in the levels of proinflammatory cytokines TNF-α and IL-6. It has been determined that the application of these solutions reduces postoperative adhesion formation. It was concluded that TNF-α and especially IL-6, which are proinflammatory cytokines, can be a non-invasive biomarker in determining postoperative IA formation and evaluating the adhesive process.

Phase Inversion Gelation Process and Additive Effects on Hydrogel Film Properties of Cotton Cellulose.

During the preparation of cotton cellulose hydrogels using the phase inversion gelation method of N,N-dimethylacetamide/LiCl solution under ethanol vapor, acetone (AC), methyl ethyl ketone (MEK), or diethyl ketone (DEK) were added as additives, and their gelation state and the properties of the resulting hydrogels were evaluated. Adding the ketones to the cellulose solution caused an increase in the gelation time, but the solution viscosity decreased, indicating that the cellulose tended to aggregate in the solution. Among the hydrogels prepared by adding ketones, the water content was as high as 2050%, especially for AC and MEK. In these hydrogels, cellulose formed an agglomerated fibrous network of a few micron widths, forming a tuft-like entrapment space of about 10 to 100 μm size. The structure surrounded water and held it in the hydrogels. The FTIR results showed that the water, which formed hydrogen bonds, was retained within the hydrogel network. This structural configuration was determined to be conducive to maintaining the gel state against external deformation forces, especially in the case of the addition of MEK.

Hollow Filaments from Coaxial Dry-Jet Wet Spinning of a Cellulose Solution in an Ionic Liquid: Wet-Strength and Water Interactions.

Hollow tubing and tubular filaments are highly relevant to membrane technologies, vascular tissue engineering, and others. In this context, we introduce hollow filaments (HF) produced through coaxial dry-jet wet spinning of cellulose dissolved in an ionic liquid ([emim][OAc]). The HF, developed upon regeneration in water (23 °C), displays superior mechanical performance (168 MPa stiffness and 60% stretchability) compared to biobased counterparts, such as those based on collagen. The results are rationalized by the effects of crystallinity, polymer orientation, and other factors associated with rheology, thermal stability, and dynamic vapor sorption. The tensile strength and strain of the HF (dry and wet) are enhanced by drying and wetting cycles (water vapor sorption and desorption experiments). Overall, we unveil the role of water molecules in the wet performance of HF produced by cellulose regeneration from [emim][OAc], which offers a basis for selecting suitable applications.

Incorporation of bioactive compounds from avocado by-products to ethyl cellulose-reinforced paper for food packaging applications.

Reinforced films were fabricated by impregnating paper in ethyl cellulose solutions. After solvent evaporation, the infused ethyl cellulose acted as binder of the paper microfibres and occupied the pores and cavities, thus improving the mechanical and barrier properties. To prepare active films, avocado by-products from guacamole industrial production were extracted in ethyl acetate. Then, the extract (optimized to be rich in phenolic compounds and flavonoids and mainly composed by lipids) was incorporated to the paper reinforced with the highest content of ethyl cellulose. In general, the addition of the avocado by-products extract decreased the water uptake and permeability, improved the wettability, and increased the biodegradability in seawater and the antioxidant capacity. In addition, these films acted as barriers and retainers for Escherichia coli and Bacillus cereus. The potentiality of these materials for food packaging was demonstrated by low overall migrations and a similar food preservation to common low-density polyethylene.

Adsorption properties of cellulose beads prepared by emulsion-gelation method and subsequent oxidation

Cellulose beads with diameters in the micro- to millimeter scale are used in various fields. The search for a novel and straightforward method for producing cellulose beads has attracted significant research attention. In this study, we successfully manufactured cellulose beads using a simple cellulose/LiBr solution-in-oil emulsion-gelation method. Subsequently, we evaluated the dye adsorption capacity of the resultant cellulose beads. The effects of the ratio of the cellulose solution to oil, surfactant concentration, stirring speed, cellulose concentration, and type of surfactant on the size of the beads were investigated. The cellulose beads exhibited a highly porous structure, with a high specific surface area and high adsorption performance for the anionic dye Congo red. In addition, carboxyl groups were introduced into the cellulose beads by oxidation, while retaining their highly porous structure. The adsorption capacity of the cationic dye methylene blue on the oxidized cellulose beads significantly increased with increasing oxidation time and carboxyl group content. In contrast, the adsorption of the anionic dye, Congo red, was inhibited. Cellulose beads with a high carboxyl group content maintained a high adsorption capacity even after repeated adsorption-desorption cycles, demonstrating their potential as reusable adsorbent materials.

Research on topological effect of natural small molecule and high–performance antibacterial air filtration application by electrospinning

The application of natural small molecule (NSM) in electrospun fibers is the key to achieving powerful functionality and sustainable development. However, the lack of understanding regarding the mechanism for loading NSM hinders the advancement of high–performance functional fibers. This work clarified the loading mechanism of NSM in polymer solution by comparing the different behaviors of curcumin (Cur), phloretin (PL), and tea polyphenols (TP) blended ethyl cellulose (EC) solutions. We found that TP may lead to the folding of polymer chains due to its strongest hydrogen bond, which in turn promoted the dispersion of TP along the polymer chain. Therefore, TP could achieve good electrospinnability at the highest loading capacity (16 times the Cur and 4 times the PL). Finally, chitosan was introduced into EC/TP to prepare tree–like nanofibers, achieving high–performance antibacterial air filtration. The filtration efficiency for 0.3 μm NaCl particles, pressure drop, and quality factor were 99.991 %, 85.5 Pa, and 0.1089 Pa−1, respectively. The bacteriostatic rates against Escherichia coli and Staphylococcus aureus were all 99.99 %. This work will promote the application of NSM and the developments of multifunctional electrospun fibers and high–performance air filters.

Coated Porous Microneedles for Effective Intradermal Immunization with Split Influenza Vaccine.

In order to alleviate the pain associated with subcutaneous injections, microneedles (MNs) are gaining increasing attention as a novel transdermal drug delivery modality. Among them, porous microneedles (pMNs) are particularly suitable for the delivery of drugs and vaccines whose activity is sensitive to the microneedle preparation process. They can carry drugs actively to achieve an effective load and deliver drugs into the skin. In this study, the biocompatible cellulose acetate (CA) microporous MNs with a large pore size of 1.13 μm ± 0.45 and a high porosity of 74.8% ± 2.8% were prepared by using a safe nonsolvent-induced phase separation (NIPS) method. The MN patches prepared after adsorption of appropriate concentrations of split influenza vaccine fully met the dose loading requirements. A biocompatible carboxymethyl cellulose (CMC) solution was used in the pMN coating to strengthen their mechanical properties, with an average maximum stress of 32.89 N, and to act as a medium for the dispersion of an adjuvant in the coating layer. The influenza vaccine adsorbed in the micropore and the adjuvant dispersed in the coating were released intradermally to exert synergistic effects with different release patterns and rates. The coated pMNs induced an efficient immune response in Wistar rats with a hemagglutination inhibition (HI) titer of ≥1024, which was comparable to that of intramuscular injection. The research is organized around the goal of engineering exploration of innovative technologies, suggesting that pMNs have a tantalizing prospect for future applications. It opens up the possibility of eventually obtaining a simple, easy-to-use, and efficient application technology for the prevention of global epidemics like influenza.

Turbulent flow of a shear-thinning non-Newtonian CMC-based nanofluid in twisted finned tubes with an elliptical profile

In this article, the forced convective turbulent flow of a shear-thinning non-Newtonian nanofluid through twisted tubes with elliptical cross sections is numerically studied and analyzed at various Reynolds numbers. The base fluid of the studied nanofluid is 0.5% carboxymethyl cellulose solution in water (which has non-Newtonian behavior of shear-thinning), and it contains copper oxide nanoparticles. Two types of twisted tubes are considered: finned tubes and unfinned ones. The finite volume method is utilized, and the two-equation model of k-ε has been applied to analyze the flow characteristics of the turbulent problem. The computational results demonstrate an excellent agreement with respect to already published reports, which is a testament to our reasonable and correct procedure. The effects of pipe wall twisting on the average Nusselt number have been investigated. The achievements demonstrate a powerful secondary and rotating flow is formed with the tube surface twisting. This secondary flow causes better mixing and increases the average Nusselt number. The increase is up to 45% for the unfinned case and 62% for the finned case in comparison with the tube without projections. In addition, the coefficient of friction in these pipes increases to 62% and 104% for the unfinned and finned tubes, respectively. It is also observed that by increasing the length of the fin and adding nanoparticles up to 1.5%, the highest value of the performance evaluation criterion (i.e. 1.78) in the twisted finned tube could be achieved, which occurred at the Reynolds number of 4000. The combination of present geometry and the working fluid of shear-thinning non-Newtonian CMC-based nanofluid is the main novelty of this work, and the results can be applicable and reliable in the relevant industries.

Transparent regenerated cellulose film containing azobenzene group with reversible stimulus discoloration property

The cellulose film, exhibiting color alterations in response to external stimuli, presents itself as a promising functional material. In this study, a universal dissolution-regeneration technique was employed to manufacture a transparent, regenerated cellulose film, characterized by its reversible multi-stimulus discoloration property. This functional cellulose film, endowed with both photochromic and acid-chromic attributes, was synthesized through the introduction of a cellulose-grafted azobenzene derivative into the cellulose solution. The hue of a cellulose film irradiated with ultraviolet light could be inverted upon exposure to visible light or heat. Furthermore, when subject to heating, irradiation, or immersion in an acidic medium, this functional film demonstrated pronounced transparency. The acid-chromic behavior of the film was readily discernible when exposed to highly concentrated acidic aqueous solutions. Both the photochromic and acid-chromic phenomena were discernable to the unaided eye. After ten cycles, no fading of the reversible discoloration properties of the material occurred. This transparent regenerated cellulose film stands as a viable candidate for applications in optical data storage, intelligent switches, and sensors, owing to its capacity for reversible stimulus-triggered discoloration.

Development of cellulose films by means of the Ioncell® technology, as an alternative to commercial films

In recent years, the search for alternatives to petroleum derived products, such as plastic films, has become a priority due to the growing depletion of fossil reserves and the pollution of water resources by microplastics, microscopically small plastic particles which are harmful to ocean and aquatic life. Cellulose-based films, e.g., cellophane and cuprophane, have been on the market for almost a century. Despite being a more ecological option compared to plastic films, the manufacture of these cellulose films involves high production costs and the use of harmful chemicals. As an alternative, a sustainable and eco-friendly process based on the Lyocell-type Ioncell® technology is presented to produce cellulose films. Regenerated cellulose films are created by continuous extrusion via dry-jet wet spinning of an ionic liquid–cellulose solutions. The influence of the polymer concentration (8–13 wt%) and processing temperature (50–100 °C) on the properties of the films were studied by the determination of the thickness, mechanical properties, physical appearance, morphology, chemical composition, and hydrophobicity. The obtained films are thin (12–21 μm), transparent (transmittance = 91%) and of homogeneous structure. Moreover, they exhibit excellent mechanical properties: stress values up to 210 MPa and elongations up to 19% in machine (longitudinal) direction. These values clearly outperform commercial cellophane, which presents stress values of 125 MPa and elongations of 22%. The films presented herein hold great potential to become an eco-friendly and sustainable option to commercial films.

Recent Advances in Functional Cellulose-based Films with Antimicrobial and Antioxidant Properties for Food Packaging.

The packaging of food plays a crucial role in food preservation worldwide. However, traditional packaging systems are passive layers with weak efficiency in protecting the food quality. Therefore, packaged foods are gradually spoiled due to the oxidation and growth of microorganisms. Additionally, most of the commercial packaging films are made of petroleum-based materials which raise environmental concerns. Accordingly, the development of eco-friendly natural-derived active packaging systems has increased the attention of scientists. Cellulose as the most abundant polysaccharide on earth with high biocompatibility, no toxicity, and high biodegradability has extensively been applied for the fabrication of packaging films. However, neat cellulose-based films lack antioxidant and antimicrobial activities. Therefore, neat cellulose-based films are passive films with weak food preservation performance. Active films have been developed by incorporating antioxidants and antimicrobial agents into the films. In this review, we have explored the latest research on the fabrication of antimicrobial/antioxidant cellulose-based active packaging films by incorporating natural extracts, natural polyphenols, nanoparticles, and microparticles into the cellulose-based film formulations. We categorized these types of packaging films into two main groups: (i) blend films which are obtained by mixing solutions of cellulose with other soluble antimicrobial/antioxidant agents such as natural extracts and polyphenols; and (ii) composite films which are fabricated by dispersing antimicrobial/antioxidant nano- or microfillers into the cellulose solution. The effect of these additives on the antioxidant and antimicrobial properties of the films has been explained. Additionally, the changes in the other properties of the films such as hydrophilicity, water evaporation rate, and mechanical properties have also been briefly addressed.

Rheological properties of carboxymethyl cellulose (CMC) solution: Impact of high intensity ultrasound

Today sonication process is used as a new green tool with unique impacts on foods preservation and processing. Ultrasonic modification is an appropriate strategy to obtain good gums with useful physicochemical characteristics and molecular structure. This research aimed to analyze the impacts of sonication at different intensities (0, 75, and 150 W) and time (0, 5, 10, 15, and 20 min) on the viscosity and rheological characteristics of carboxymethyl cellulose (CMC) solution. The results confirmed that the apparent viscosity of CMC solution reduced from 0.030 to 0.021 Pa.s with increasing shear-rate from 12.2 s−1 to 134.5 s−1 (75 W for 10 min). Also, the apparent viscosity of CMC solution reduced from 0.028 to 0.019 Pa.s with enhancing the sonication time from 0 to 20 min (shear-rate = 61 s−1, 150 W). Various rheological equations were employed to fit the empirical values, and the results confirmed that the Power law model was the best fit to explain the flow behaviour of CMC solution. The consistency coefficient of CMC solution significantly reduced from 0.065 Pa.sn to 0.032 Pa.sn (p < 0.05) with enhancing sonication time from 0 to 20 min (75 W). Furthermore, the consistency coefficient of CMC solution decreased significantly (p < 0.05) while the ultrasonic power enhanced. Flow behaviour index of CMC solution enhanced significantly (p < 0.05) while the intensity and time of sonication enhanced.

Utilization of an aqueous two-phase emulsification to prepare bimodal porous cellulose monolith for efficient adsorption of bovine serum albumin

Cellulose monolith has garnered significant interest in the field of biochromatography, which lies in its interconnected porous structure, large surface area and biocompatibility. In this context, we propose a novel approach for preparing cellulose monoliths using an aqueous two-phase system devoid of any organic solvents and surfactants. In this strategy, emulsifying cellulose solution into PEG 20,000 solution gives bicontinuous aqueous phases and further porous cellulose monolith after regeneration of dissolved cellulose. And the macroporous channels are derived from the removal of the PEG 20,000 aqueous phase while the micropores are from the phase separation of the cellulose phase. Physical characterizations reveal the obtained cellulose monolith exhibits exceptional column permeability of 1.36 × 10−11 m2 and a substantial surface area of 39.34 m2/g. Furthermore, cellulose monolith is functionalized with diethyl ethylamine hydrochloride (DEAE-HCl) to evaluate its potential as an anion adsorbent. Experimental results reveal that the DEAE-modified cellulose monolith possesses of adsorptive capacity of 316.58 mg/g of bovine serum albumin, along with fast adsorption kinetic. This study introduces an innovative strategy for fabricating porous cellulose monoliths tailored for biochromatography applications.