Cellulose最新文献

Ample fabrication techniques have been developed to create hydrophobic patterns, including but not limited to photolithography, wax printing, inkjet printing, laser printing, flexographic printing, stamping, 3D printing, hydrophobic ink plotting, spraying, and various cutting techniques such as laser cutting and manual craft cutting. However, their effects on capillarity-driven fluid flow on porous paper substrates remain unexplored. Our study examines how fabrication methods influence the paper's porous structure and fluid imbibition behavior. These diverse methods can be broadly classified into three categories based on their interaction with the paper substrate: (a) cutting with scissors (no hydrophobic barriers, surface-intact techniques), (b) laser cutting (no hydrophobic barriers, edge-cutting techniques), and (c) toner printing to create hydrophobic barriers (full surface exposure technique). Our analysis reveals a ~ 0.8–1 µm increase in surface roughness compared to untreated paper, with no significant changes in hydrophilic properties regardless of the technique used. The results show that fluid imbibition is primarily influenced by substrate modifications caused by fabrication, which is more pronounced. In sharp contrast to existing research findings, we pinpoint the influence of different fabrication processes on imbibition flow mechanism which is much more pronounced rather than envisioning the effects of geometric factors on such imbibition. For lower channel widths (2–4 mm) the influence of fabrication processes becomes even crucial. The travel duration for the laser cutter, single-side printed, double-side printed, and blank roll methods are 1.66, 2.33, 2.33, and 2.66 times longer, respectively, than the scissor-cut surface for Whatman grade 4 filter paper. These insights highlight critical design considerations for developing paper-based devices in biosensing applications.

Cellulose-based composite materials have attracted increasing interest among scientists working on developing energy-storage materials with unique properties. In the present study, an aerogel was synthesized from sunflower seed husk (SFH) to form microcrystalline cellulose (MCC), the hydrogen (H₂) sorption potential of which was then investigated. The effect of MCC concentration on the nitrogen sorption capacity of the aerogel samples obtained was assessed based on comparison with other like materials. As per the results of BET analysis, the aerogel with an MCC concentration of 3% was determined to be microporous, with a specific surface area of 3000 cm²/g, average pore diameter of 29.7 nm, total pore volume of 0.44 cm³/g, density of 166 kg/m³, and porosity of 95%. It was found that at a temperature of 77 K and up to 1 bar, MCC₃/polyacrylamide (PAm) aerogel can sorb up to 0.8% hydrogen. Additionally, the results of SEM analysis revealed a microporous surface morphology, while FTIR analysis showed that the hydroxy groups in the MCC molecule and the amino groups in the PAm molecule form hydrogen bonds with each other. The results of the research indicate that such an aerogel has potential for use as a material for H₂ storage, and appears to be more ecologically friendly than the metal hydrides used in many H₂ fuel cells and storage containers, the end-of-life processing of which remains a relatively unexplored issue. Generally, cellulose is considered to be a highly desirable material from both ecological and economic perspectives.

Date pomace from industrial residues has not been widely used as a source of cellulose. Cellulose nanofibers (CNFs) from date pomace, along with plasticizers, help overcome the limitations of chitosan-based films. The functionality of composites as intelligent packaging can be achieved by adding anthocyanins. This study investigates the synergistic effects of adding CNFs from date pomace and glycerol on the physical and mechanical properties of chitosan-based films that have not been studied before, and evaluates the effect of anthocyanins on the total color change of the film for its application as intelligent packaging. CNFs were prepared through ultrasonication and acid treatment of cellulose pulp from date pomace. Chitosan, CNFs, and glycerol were blended with CNF content up to 10% wt, followed by solvent casting and drying. Anthocyanins with various amounts of up to 5% w/v were composited into the best formula, followed by an evaluation of the film discoloration at different pHs. The morphology, functional group, X-ray diffraction, and physical and mechanical properties were evaluated from the composite. The addition of glycerol and CNFs from date pomace is proven to synergistically improve pure chitosan film’s physical and mechanical properties. The chitosan-glycerol-CNF composites produce tensile strength and break strain 1.3 times and 7 times that of pure chitosan film. Its composite with anthocyanins shows its potential application as a sensitive intelligent packaging between pH 3–4, 4–5, and 6–7.

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Bacterial cellulose (BC) production using cost-efficient food waste substrates was investigated with Komagataeibacter sucrofermentans, targeting fruit peels (orange, banana, watermelon), staple foods (rice, noodles, steamed bread), and waste pepper. After 7 days of static culture, rice medium yielded the highest BC (12.03 ± 0.56 g/kg), followed by watermelon peel (10.54 ± 0.09 g/kg) and mixed staple foods (10.30 ± 0.56 g/kg). Pepper-derived BC (P-BC) exhibited the highest crystallinity index (79.89%), attributed to phenol-mediated hydrogen bonding, while rice- and watermelon-derived BC (R-BC and W-BC) showed excellent tensile strengths (54.29 and 66.03 MPa, respectively) attributed to dense fiber networks. A Brunauer–Emmett–Teller analysis revealed some macropores in orange peel-derived BC (O-BC, up to 1170 nm) with a specific surface area (SSA) of 32.09 m²/g and mostly mesopores in P-BC (4–118 nm) with a smaller SSA. Large pore sizes in R-BC (up to 1190 nm) enabled the highest observed water-holding capacity of 97.36 g per g of dry weight. A one-step sterilization/extraction method reduced the need for enzymatic pretreatment, demonstrating its feasibility for sustainable BC production. Furthermore, this study highlights waste pepper as a novel substrate and underscores the impact of food waste sources on BC microstructure and functional properties, advancing circular economy approaches for biopolymer synthesis.

The advancement in sustainable technology and increasing demand for sustainable biomaterials, coupled with the quest to reduce environmental footprint, have promoted research on cellulose, particularly bacterial cellulose (BC). BC, synthesized by bacteria, is a highly pure form of cellulose characterized by a unique combination of properties, including biocompatibility, mechanical strength, water-holding capacity, biodegradability, and non-toxicity. Beyond these attributes, BC has gained great interest recently in both academic and industrial sectors, demonstrating great benefits for application in various industries, including food. This review provides a comprehensive analysis of BC, covering its synthesis, structural composition, physicochemical properties, production methodologies, safety considerations, and relevant patents. Recent advances in bacterial cellulose research, particularly its applications in the food sector—including food packaging, novel food formulations, nutraceuticals, and personalized nutrition—are critically examined. Additionally, this review presents a concise discussion on the prospective developments of BC in food applications. BC has been explored for edible coating (EC), active packaging, dietary fiber, immobilization agent, emulsifier, and Pickering emulsion (PE); however, its potential for future innovations within the food industry remains substantial.

The study explores the development of sustainable epoxy composite reinforced with cellulose extracted from corncob, an abundant agricultural waste, to address environmental concerns and enhance material properties. The cellulose from corncob was extracted using an optimized NaOH treatment. Epoxy composites with varying percentages (5 wt.%, 10 wt.% and 20 wt.%) of cellulose were prepared by hand casting method (labelled EC05, EC10 and EC20). The composites were characterized through mechanical (tensile, flexural and impact tests) and thermal tests (DSC analysis) along with FTIR, XRD and SEM analyses. The finding revealed that 5 wt.% cellulose loaded composite exhibited an enhancement in tensile (26.20 MPa), flexural (47.47 MPa) and impact strength (41.61 J/m) by 44%, 104% and 63%, respectively, compared to EP. Higher filler concentration (10 wt.% and 20 wt.%) resulted in agglomeration of particles, which led to reduction in mechanical properties, due to matrix discontinuity and stress concentration. DSC revealed improved thermal stability with increased filler concentration. SEM images revealed relatively uniform filler dispersion in EC05, while FTIR and XRD confirmed cellulose incorporation and reduction in crystallinity at higher filler addition. These findings underline the feasibility of corncob cellulose as a sustainable reinforcement.

In this study, spent coffee grounds (SCG) were used to prepare 2,2,6,6-tetramethylpiperidin-l-oxyl radical (TEMPO)-oxidized SCG-derived cellulose nanofibers (TCCNs), and the rheological properties of TCCNs were explored. Physicochemical characterization indicated successful TEMPO-mediated oxidation, and the TCCNs exhibited high aspect ratios. In steady shear rheological measurements, TCCN suspensions (2.32, 1.88, and 1.44 wt%) all demonstrated highly shear-thinning fluidic behaviour, indicating high sensitivity to shear stress. The apparent viscosity and thixotropic properties increased with increasing concentration. The Herschel–Bulkley and Cross models provided a superior description of the suspension flow behaviour. Dynamic oscillatory measurements revealed a typical response indicative of weak gels in TCCN suspensions. As the concentration increased, the linear viscoelastic region expanded, accompanied by a decrease in the frequency sensitivity, indicating a stronger gel network. Furthermore, TCCN suspensions exhibited exceptional self-assembly abilities and thermally irreversible hydrogel behaviour. The incorporation of TCCNs into styrene-acrylic latex-based paper coatings led to increased thickening at low shear rates and outstanding shear-thinning behaviour at high shear rates. These results indicated that TCCNs have promise as an environmentally friendly and sustainable additive for various applications (e.g., food, personal care, and coating products).

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Poly(methyl methacrylate) (PMMA) is widely used in dental prosthetics due to its aesthetic and functional properties. However, its susceptibility to fracture, wear, and mechanical degradation under oral forces limits its longevity and performance. Enhancing PMMA’s mechanical properties is crucial for improving the durability of oral rehabilitations, reducing failure rates, and ensuring better patient outcomes to withstand oral forces. This systematic review evaluated the influence of Cellulose Nanomaterials (CNs) on PMMA’s mechanical properties. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, the study was registered on the Open Science Framework (osf.io/sthvf). A literature search across seven databases (up to December 2024) identified 2190 studies. After removing Duplicates and applying the eligibility criteria, 28 were qualitatively assessed. 16 studies presented a moderate, and 12 presented a low risk of bias. Of 28 studies reviewed, 26 reported that CN-functionalized PMMA improved flexural strength, tensile strength, impact strength, storage modulus, microhardness, and rupture strength. CNs enhance PMMA’s mechanical properties, with CNF excelling in impact resistance, making it highly promising for dental applications.

The feasibility of using artificial seawater (ASW) instead of fresh water as the medium for reactive dyeing of cotton fabric is investigated in this study. A number of dyes of different reactive groups are used. Cotton fabrics are dyed in ASW media with (ASW+) or without (ASW−) further addition of NaCl and their dyeing, colourfastness, surface and physical properties are examined and compared with cotton fabrics dyed in deionised (DI) and distilled (DIS) water media. Although nearly all ASW dyed fabrics obtain lower colour yield (0.7–65.2% lower) than that of DI and DIS dyed fabric, the results of this work reveal that triazine-based reactive dyes disfavour cotton dyeing in DIS and ASW (ASW− and ASW+) media (0.2–65.2% lower) while fluorochloropyrimidine (FCP)-based and dichlorochinoxaline (DCC)-based monofunctional reactive dyes in DIS and ASW dyeing system offer better colour yield (5.8–72.5% higher). The pH value and salinity of the dyebath in those four different dyeing media are measured. The reflectance curves, CIE L*a*b* value, colour evenness, fastness, surface, fastness and tensile properties of the dyed cotton fabrics are evaluated. The findings verify that the use of ASW does not alter the colour properties of the dyed specimens. Both DI, DIS and ASW dyed specimens reflect good to excellent colour levelness (0.01–0.46) and fair to excellent washing, crocking and perspiration fastness properties (rating 3–4 to 5) without any significant fibre damage while both exhibit lower breaking strength and extension after the dyeing process when compared with pristine undyed cotton fabric.

This study investigates the influence of harvest date on the morphological, physicochemical, and mechanical properties of Triumfetta cordifolia (TC) fibers a relatively underutilized plant resource from equatorial regions. Two maturity stages were considered: early harvest (TCF-EH) and late harvest (TCF-LH). The fibers were characterized using microscopy (SEM), elemental analysis (EDX), structural analysis (XRD), thermal analysis (DSC), and biochemical profiling (HPLC-PAD). Tensile tests revealed that TCF-EH fibers exhibited higher crystallinity (64%), smaller average diameters, a moderate microfibril angle (8.47°), and superior tensile strength (up to 529 MPa) compared to TCF-LH fibers. Additionally, TC fibers were benchmarked against flax and hemp fibers, positioning TCF-EH as a viable alternative for lightweight composite applications. TCF-EH fibers exhibited a tensile strength of 529 MPa, a Young’s modulus of 33.1 GPa, and a crystallinity index of 64%, highlighting their maturity-related superiority. This work highlights the critical role of harvest timing in optimizing the performance of natural fibers, contributing to the broader development of sustainable plant-based resources for bio-based materials. This is the first comprehensive study evaluating how harvest date affects the structural and functional properties of Triumfetta cordifolia bast fibers for biocomposite applications, providing novel insights for optimizing harvest timing to improve fiber performance.