Natural Cellulose Fibers Research Articles

Investigating the Routes to Produce Cellulose Fibers from Agro-Waste: An Upcycling Process

The agriculture and agri-food sectors produce substantial amounts of plant-based waste. This waste presents an identifiable research opportunity to develop methods for effectively eliminating and managing it in order to promote zero-waste and circular economies. Plant-based waste and by-products are acknowledged as valuable sources of bioactive compounds, including cellulose fibers. Direct application of these fibers in non-food sectors such as textiles can reduce the environmental impact of secondary raw materials. This review aims to provide an overview of novel concepts and modern technologies for efficiently utilizing plant-based waste and by-products from the agricultural and agro-industrial sectors to extract fibers for a variety of final applications, including the fashion industry. Two major routes are identified to produce cellulose fibers: the extraction and purification of natural cellulose fibers and the extraction and purification of cellulose pulp that is further processed into manmade cellulosic fibers. Scalability of experimental results at the laboratory or pilot level is a major barrier, so it is critical to develop closed-loop processes, apply standardization protocols, and conduct life cycle assessments and techno-economic analyses to facilitate large-scale implementation.

Sources Affecting Microplastic Contamination in Mountain Lakes in Tatra National Park

The global atmospheric transport of microplastics (MPs) plays a crucial role in the contamination of remote, especially higher-elevation, environments. Precipitation is considered the main source of MP pollution. Meanwhile, plastic waste generated from, for example, tourism activities can be a local source of MP pollution. In this study, we specify which of the mentioned sources of MP, global or local, have a higher impact on the pollution level in the high-elevation oligotrophic lakes of Tatra National Park in Poland. Due to its unique natural value, it is listed by UNESCO as an international biosphere reserve and meets the criteria for Natura 2000 areas. We comprehensively analyzed the morphometric and anthropogenic features of 11 lakes in terms of the contamination level, color, shape, and polymer type of the MPs found in the surface waters. MP fibers were found to be present in all studied lakes, with contamination ranging from 25 to 179 items/m3. Polypropylene, polyethylene terephthalate, and natural or semi-natural cellulose fibers—black or red in color with a length of 0.2–1.0 mm—predominated, which corresponds with other studies conducted on remote mountain ecosystems. We did not find any correlation of the number of MPs with local anthropogenic pressure characteristics. In turn, the significant correlation with lake area, coastline length, lake volume, and catchment area indicated airborne sources, including global transport of MPs to the lakes with reduced water outflow.

Melt processing of chemically modified cellulosic fibres with only water as plasticiser: Effects of moisture content and processing temperature

To replace petroleum-derived polymers with cellulose fibres, it is desirable to have the option of melt processing. However, upon heating, cellulose degradation typically starts before the material reaches its softening temperature. Alternatives to plastics should also, ideally, be recyclable via existing recycling streams. Here, we address the problem of melt processing cellulose as fibres while preserving recyclability. Native cellulose fibres were partially modified to dialcohol cellulose to impart thermoplastic characteristics. We demonstrate melt processing of these modified fibres with only water as plasticiser. Processability was investigated at selected processing temperatures and initial moisture content by monitoring the axial force of the extruder screws as a rheological indicator. The effects on molecular structure, fibre morphology and material properties were characterised by NMR spectroscopy, microscopy, tensile testing, fibre morphology analysis and X-ray diffraction. When comparing the melt-processed extrudate with handsheets, the already exceptional ductility was further increased. Moderate losses in tensile strength and stiffness were observed and are attributable loss of crystallinity and fibre shortening. This is the first report of strong and durable extrudates using cellulosic fibres as the only feedstock. Finally, the potential for recycling the processed material with unmodified fibres by paper recycling procedures was demonstrated.

Pretreatment and dyeability analysis of cotton and novel Bauhinia vahlii fiber

The textile industry is witnessing a paradigm shift towards sustainable materials, prompting the exploration of novel natural fibers as alternatives to synthetic fibers to meet environmental standards and address the growing demand for eco-friendly and sustainable products. Different natural fibers possess varied properties and are suitable for numerous applications in conventional and technical textiles. The coloration of these textile materials is an important aspect of conventional textiles, which starts with the pretreatment of the material. This study introduces a novel blend of cotton and Bauhinia vahlii fiber, a lesser-known natural cellulosic fiber with promising textile properties, and evaluates its pretreatment outcomes and dyeability characteristics. The study employs a systematic approach to pretreat the cotton and Bauhinia vahlii fiber blend (cotton: Bauhinia vahlii fiber 70:30) in a single bath using a conventional combined scouring bleaching process. The pretreatment process is carried out two times with varied sodium hydroxide (NaOH) and hydrogen peroxide (H2O2) concentrations for different processing times at 90 °C to assess the component fibers’ whiteness index, union bleaching balance, and weight loss percentage under diverse pretreatment conditions. Each time, 50% of the chemicals were used and continued for half of the processing time. The dyeability of the treated fibers is analyzed by dyeing the same in a single bath using amron bright red HF2R bifunctional reactive dye in varied shade depths (1%, 3%, and 5%) and fiber blend ratios (cotton: Bauhinia vahlii fiber 100:0, 90:10, 80:20, 70:30, and 0:100) to assess the color strength, union dyeing balance, and fastness properties. The maximum whiteness was achieved with 6 g per liter (gpl) of NaOH and H2O2 and at a processing time of 150 min with a whiteness index of 80.46 and 54.34 of cotton and Bauhinia vahlii fiber, respectively, with a union bleaching balance of 1.48. The dyed fibers’ colorimetric results confirm that Bauhinia vahlii fiber gives higher color strength than cotton fiber, irrespective of shade depth and blend ratio. The union dyeing balance of 1.2 was achieved at 5% shade depth with a 70:30 cotton Bauhinia vahlii fiber blend. This research contributes to the conventional textile field by introducing a sustainable fiber blend that reduces reliance on synthetic fiber and opens new avenues for utilizing Bauhinia vahlii fiber in conventional textile manufacturing.

Implementation of Cellulose-Based Filtration Aids in Industrial Sunflower Oil Dewaxing (Winterization): Process Monitoring, Prediction, and Optimization.

In the production of refined sunflower oil, waxes are removed during the winterization stage, and wax crystals are separated through filtration assisted by filtration aids. Commonly used filtration aids in oil refining include perlite and diatomaceous earth. After winterization, a significant amount of filter cake remains as a by-product and is treated as waste. Today, natural cellulose fibers are being promoted as filtration aids. Their advantages are numerous, both in the production process and from an environmental perspective. However, their only disadvantage is their higher cost. Therefore, in this study, 57 filtration cycles during the industrial sunflower oil winterization step using cellulose-based filtration aids were monitored. Different process parameters, including the pressure differential on the filter, the flow rate of filtered oil, constant pressure period, the quantity of filtered oil, filtration time, the quantity of pre-coating and dosing filtration aids, the volume of filtered oil, the concentration of dosing filtration aid, as well as the mass of separated waxes, were observed. Additionally, artificial neural networks were applied to predict process parameters, optimize the process, and, above all, determine the dosage of filtration aids, which will make the process more economical. The optimal filtration process is performed at a pressure differential of 3.3 bar, lasting a total of 39 h, with 32 h at constant pressure, resulting in 322,503 kg of filtered oil and 90.41 kg of waxes. The optimal quantity of cellulose-based filtration aids employed for pre-coat was 80 kg, and for dosing, 375 kg, with an optimal concentration of 0.12% w/w.

Using CO2 in pyrolysis to neutralise toxic aromatic compounds derived from blended textile waste

Blended textiles are favoured for their enhanced properties, combining the strengths of constituent fibres (typically synthetic fibres integrated with natural cellulosic fibres). However, the presence of aromatic components in blended textile waste (BTW) complicates its disposal and raises environmental concerns due to the release of toxic chemicals. To resolve this issue, this study suggests a pyrolysis system as a strategy to neutralise toxic aromatic compounds derived from BTW. Carbon dioxide (CO2) was used as the partial oxidative reagent. The characterisation of BTW revealed its composition, containing rayon and polyester. The complex composition of BTW, particularly the recalcitrant nature of polyester, leads to the massive generation of toxic aromatic chemicals, such as terephthalic acid and its analogues, during thermolysis. However, introducing CO2 to pyrolysis facilitates interacting with these toxic compounds, converting them into carbon monoxide (CO). The effectiveness of CO2 for the suppression of toxic aromatic formations was further enhanced when adopting a nickel-based catalyst. CO2-assisted catalytic pyrolysis achieved a 64.87 % reduction in toxic aromatic chemicals and an 11.36-fold increase in CO production compared with conventional pyrolysis. This study presents a promising approach for the sustainable disposal of BTW, emphasising the oxidative functionality of CO2 in neutralising toxic aromatic chemicals into detoxified products, especially CO.

Green synthesis of multifunctional bamboo-based nonwoven fabrics for medical treatment

Medical nonwovens fabrics are pivotal materials in modern healthcare systems, and find extensively application in surgical gowns, masks, nursing pads, and surgical instrument packaging. As healthcare requirements evolve and medical technology advances, the demand for functional nonwoven medical devices is continuously increasing. In addition, numerous environmental challenges and the need to transition to a sustainable society have increased the popularity of studies on environmentally friendly multifunctional nonwoven materials prepared from biomass fibers. Therefore, in this study, ecofriendly bamboo fibers were used to fabricate multifunctional medical nonwoven materials with superhydrophobic, antibacterial, flame-retardant, and biocompatible properties. Specifically, ZIF-67 was grown in situ on natural bamboo cellulose fibers (BCFs) extracted from natural bamboo and coated with polydimethylsiloxane to construct an environmentally friendly and versatile nonwoven fabric. The treated nonwoven fabric exhibited superhydrophobicity with contact angle of 163° and possess excellent self-cleaning properties. The antibacterial activity of the samples was investigated by the plate-counting method; the results showed that the untreated BCFs did not exhibit antibacterial activity, whereas the treated bamboo nonwoven fabrics demonstrated significant antibacterial activity (p < 0.001), with an antibacterial rate of >99 % against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, and Candida albicans. In addition, when the samples were exposed to different temperatures (−4 and 50 °C) and humidities (0 % and 95 %), they demonstrated an antibacterial activity of >99 % against E. coli (F5,10 = 0.602; p = 0.670) and S. aureus (F4,10 = 0.289; p = 0.879). The heat release rate and smoke production rate of the nonwoven fabric decreased by 54.64 % and 93.18 %, respectively, compared to those of the BCFs, indicating excellent flame retardancy. The nonwoven fabric also exhibited satisfactory biocompatibility and breathability, ensuring user comfortability. This research not only has significant implications for producing low-cost, environmentally friendly, sustainable, and multifunctional medical products and openi up new pathways for the diversified utilization of bamboo, thereby expanding its applicability.

Extraction and characterization of novel alternative cellulosic fiber for sustainable textiles from Aloe barbadensis Miller stems (agricultural waste)

Novel research has been conducted on Aloe vera, focusing on stems fiber (agricultural waste), for the extraction of cellulosic fiber, an area lacking prior scientific exploration. This fiber is being reported for the first time in the scientific community. Aloe barbadensis Miller variety was subjected to various cultivation methods, including the application of inorganic and organic fertilizers, along with the removal of lower leaves to promote stem growth. Stem fibers were extracted using the water retting method and subsequently analyzed. The moisture content was 55.35 % and 6.99 % ash content in the fibers. The bacteriostatic analysis of Aloe vera fibers was assessed against four bacterial strains, with both ethanol and water extracts showing varying degrees of inhibition zones. The UV–Visible spectrum exhibited a distinct λmax at 247 nm in ethanol, while FT-IR analysis provided characteristic peaks at 3759, 1590, 1750, 1663, 1250, 564, SEM images displayed the smooth surface morphology of the fibers, and X-ray diffraction analysis indicated a high degree of crystallinity (78.67 %), suggesting a well-structured and crystalline nature. Energy dispersive X-ray (EDX) analysis was conducted to determine the elemental composition of the fibers, revealing the presence of carbon, oxygen, calcium, and copper, with carbon being the predominant element in cellulose. These results showed promising properties suggesting potential applications in textile industry as an alternative sustainable natural cellulosic fiber.

Exploring eco-friendly pseudo stem fiber from the agricultural byproducts of the Alpinia purpurata plant

This study explored the potential of Alpinia purpurata pseudostems, an agricultural waste product, as a sustainable and eco-friendly source of natural fibers for the textile industry. The aim was to characterize the properties of natural cellulose fibers from the pseudostems of the Alpinia purpurata plant. The research employed water retting to extract the fibers, and the intrinsic fiber properties obtained were evaluated for their suitability in textile applications. The average length of an Alpinia purpurata fiber was 67.80 cm with a fineness value of 7.61 Tex. A bundle of Alpinia purpurata fibers was comprised of many elementary fibers. Alpinia purpurata had an irregular cross-section, with the lumen having a varied oval shape. The fibers exhibited tenacity and elongation values of 2.49 g/denier and 5.72 %, respectively, and a coefficient of friction value of 0.49. Additionally, Alpinia purpurata fibers were hygroscopic, with a moisture regain value of 11.97 %. The findings revealed that the fibers possessed notable tensile strength, moderate elongation, and high moisture regain, making them suitable for non-apparel textile products requiring durability and moisture management. While not the strongest among natural fibers, their sufficient strength and other advantageous properties demonstrated their viability for various applications. This work addressed a significant gap in the literature on the utilization of agricultural by-products, proposing Alpinia purpurata pseudostems as a sustainable alternative that aligned with environmentally responsible manufacturing practices and supported the circular economy. Future research was recommended to optimize processing techniques and explore broader applications.

Characterization of Azadirachta indica Natural Cellulosic Fiber and Its Polymer Composites

Characterization of Azadirachta indica Natural Cellulosic Fiber and Its Polymer Composites

Superfast, large-scale harvesting of cellulose molecules via ethanol pre-swelling engineering of natural fibers

Cellulose molecules, as the basic unit of biomass cellulose, have demonstrated advancements in versatile engineering and modification of cellulose toward sustainable and promising materials in our low-carbon society. However, harvesting high-quality cellulose molecules from natural cellulosic fibers (CF) remains challenging due to strong hydrogen bonds and unique crystalline structure, which limit solvents (such as ionic liquid, IL) transport and diffusion within CF, making the process energy/time-intensively. Herein, we superfast and sustainably engineer biomass fibers into high-performance cellulose molecules via ethanol pre-swelling of CF followed by IL treatment in the microwave (MW) system. Ethanol-pre-swelled cellulosic fibers (SCF) feature modified morphological and structural distinctions, with improved fiber width, pore size, and specific surface area. The ethanol in the SCF structure is appropriately removed through MW heating and cooling, leaving transport and diffusion pathways of IL within the SCF. Such strategy enables the superfast (140 s) and large-scale (kilogram level) harvesting of cellulose molecules with high molecular weight, resulting in high-performance, versatile cellulose ionogel with a 300 % increase in strength and 1027 % in toughness, monitoring human movement, external pressure, and temperature. Our strategy paves the way for time/energy-effectively, sustainably harvesting high-quality polymer molecules from natural sources beyond cellulose toward versatile and advanced materials.

Characterization of natural cellulosic fiber extracted from Grewia ferruginea plant stem

The use of natural fibers as reinforcement in polymer composites has gained significant attention due to their eco-friendly, and biodegradability. This study aims to extract and characterize the natural cellulosic fibers from the Grewia ferruginea stem. The fibers were extracted from plant stems using sodium hydroxide and analyzed using Fourier Transform infrared spectroscopy (FTIR) to determine chemical bonds on the fiber and functional group and Thermos-gravimetric analysis (TGA) was used to determine the thermal stability and degradation temperature of the fiber. The crystalline properties of extracted fibers were characterized by x-ray diffraction and surface morphology was characterized by Scanning electron microscopy. The chemical composition of the fibers, including cellulose, hemicellulose, lignin, moisture, extractive content, and fiber linear density, was evaluated. Tensile, thermal, and FTIR studies were conducted to assess the performance properties of the extracted fiber. The analysis revealed that the Grewia ferruginea fibers contain cellulose (60.4–72.6 wt%), hemicellulose (18.5 ± 3.1 %), and lignin (13.55 ± 2.75 %). The extracted fibers have a crystallinity index of 48.76 % and crystallite size of 5.14 nm. The fiber exhibited tenacity, breaking elongation, and Young's modulus values of (52.3 ± 6.5 cN/tex), (3.6 ± 1.8 %), and 43.5 ± 2.3 GPa, respectively. FTIR studies confirmed the presence of biopolymers in the Grewia ferruginea fiber. Additionally, the fibers demonstrated thermal stability up to 275 °C based on thermogravimetric analysis. These findings suggest that the extracted natural cellulosic Grewia ferruginea fiber has the potential to be used as a sustainable reinforcement material in polymeric composites.

Studies on characteristics of natural cellulosic fibers collected from the agro-discarded Solanum trilobatum stem waste

Studies on characteristics of natural cellulosic fibers collected from the agro-discarded Solanum trilobatum stem waste

Characterization and value-added applications of natural cellulose fibers derived from cow dung in cementitious composites

Characterization and value-added applications of natural cellulose fibers derived from cow dung in cementitious composites

Characterization of novel natural cellulose fiber from Ficus macrocarpa bark for lightweight structural composite application and its effect on chemical treatment

This study investigates Ficus Macrocarpa tree bark fibers (FMB) as a sustainable alternative reinforcement for polymer composites. The Industrial Revolution marked the evolution of polymer composites with synthetic material reinforcement, leading to environmental concerns. Natural fibers have recently gained prominence as efficient alternatives for polymer composites. Despite numerous natural fibers being considered, ensuring a sustainable raw material source remains crucial. In this study, fibers were extracted from FMB and subjected to alkali treatment to evaluate their impact on physical, chemical, and thermal properties. Initially, the extracted fibers measured 253.80 ± 15 μm in diameter, reduced to 223.27 ± 12 μm post-alkali treatment. Chemical analysis showed an increase in cellulose content to 59.7 wt%, a 23.34 % improvement over untreated fibers (48.4 wt%). The crystalline index for untreated and treated fibers measured 80.20 % and 84.75 %, respectively, with no noticeable changes in the cellulose phase. Additionally, the crystalline size increased to 3.21 nm. Thermogravimetric analysis demonstrated enhanced stability of treated fibers up to 378.87 °C, while the kinetic activation energy remained constant at 64.76 kJ/mol for both the treated and the untreated fibers. The alkali treatment further improved surface roughness to 39.26, confirmed by scanning electron microscopic images. These findings highlight the potential of cellulose fibers from Ficus Macrocarpa bark as a sustainable and environmentally friendly replacement for synthetic fibers in polymer composites. The enhanced physical properties and excellent thermal stability make them a promising choice for eco-conscious materials.

Extraction and characterization of a new natural cellulosic fiber from the Habara Plant Stem (HF) as potential reinforcement for polymer composites

In this present work, characterize the chemical, physical, thermal and Morphological behaviour of raw and alkali-treated (NaOH 5 %,10 % & 15 %) new natural cellulose Habara plant stem fiber (HF). From the chemical analysis, the 10 % alkali-treated HF obtained cellulose (67.9 %), hemicellulose (12.7 %), lignin (11.8 %) wax (0.18 %), moisture (2.44 %) and Ash (1.21 %). Fourier Transform Infrared Spectroscopy Analysis, alkali treatment effectively eliminates hemicellulose and lignin from the surfaces of natural fiber, as seen changes in the FTIR peaks at 1730, 1480, and 1140 cm−1.The X-ray analysis results indicate that, there is crystalline cellulose present, with a crystallinity level of 43.87 %, and that the other components are amorphous. In addition, the thermal stability of lignocellulosic fiber up to 230 °C was observed, and the degradation steps of each major component could be identified. The 10 % alkali-treated HF provides tensile strength of 790.9 MPa, with an elongation at break of about 3.41 %. The Scanning Electron Microscope analysis showcased the morphological changes on the fiber fractured surface, diameter variation, and impurities, etc. The Atomic Force Microscopy was used to determine the surface roughness characteristics of the HF, which confirmed the possible reinforcement in the structure of the polymer matrix composite structure.

Beyond the Surface: A Methodological Exploration of Enzyme Impact along the Cellulose Fiber Cross-Section.

Despite the wide range of analytical tools available for the characterization of cellulose, the in-depth characterization of inhomogeneous, layered cellulose fiber structures remains a challenge. When treating fibers or spinning man-made fibers, the question always arises as to whether the changes in the fiber structure affect only the surface or the entire fiber. Here, we developed an analysis tool based on the sequential limited dissolution of cellulose fiber layers. The method can reveal potential differences in fiber properties along the cross-sectional profile of natural or man-made cellulose fibers. In this analytical approach, carbonyl groups are labeled with a carbonyl selective fluorescence label (CCOA), after which thin fiber layers are sequentially dissolved with the solvent system DMAc/LiCl (9% w/v) and analyzed with size exclusion chromatography coupled with light scattering and fluorescence detection. The analysis of these fractions allowed for the recording of the changes in the chemical structure across the layers, resulting in a detailed cross-sectional profile of the different functionalities and molecular weight distributions. The method was optimized and tested in practice with LPMO (lytic polysaccharide monooxygenase)-treated cotton fibers, where it revealed the depth of fiber modification by the enzyme.

Cellulose-based high-loading flexible electrode for lithium-ion battery with high volumetric energy density

Thick electrodes with high loading are attractive for high-energy storage devices, but they face major challenges of slow ion transfer and poor mechanical stability. Carbon templates such as reduced graphene oxide and carbon nanotube can promote the electrons transfer of thick electrodes and enhance their strength, but they still exhibit a complex producing process, slow Li+ transfer and high cost. Herein, a nanofiber network with double fast Li+ and electrons transfer pathways by the self-assembly of carbon nanoparticles on the negatively charged natural cellulose fibers was designed. The abundant oxygen-containing functional groups from the cellulose fibers enabled the electrode with abundant negative charge which can adsorb the neutral particles with strong electrostatic interaction. And the Density Functional Theory calculation demonstrates that oxygen-containing functional groups also has stronger adsorption energy for PF6− anions in electrolyte which can promote the desolvation of the solvated Li salts, thus promote Li+ transfer. After integration with lithium iron phosphate, this network achieves a robust high-loaded electrode with good electrical conductivity and shortened ion transfer pathways without traditional current collector and binder. Based on the robust electrode structure and fast transfer kinetics of electrons and Li+, the batteries exhibit excellent cycle stability with capacity retention of 98 % after long 400 cycles and high volumetric energy density of 740 Wh/L, which greatly surpass the conventional batteries with coating LiFePO4 (LFP) cathode. Given the low-cost raw materials and convenient operation, the design of self-standing flexible electrodes with high loading will offer a promising and effective strategy for other storage devices with high energy.

Utilization of used textiles for solid recovered fuel production.

One of the current important issues is the management of used textiles. One method is recycling, but the processes are characterized by a high environmental burden and the products obtained are of lower quality. Used textiles can be successfully used to produce SRF (solid recovered fuels). This type of fuel is standardized by ISO 21640:2021. In the paper, an analysis of used textiles made from fibers of different origins was performed. These were acrylic, cotton, linen, polyester, wool, and viscose. A proximate and ultimate analysis of the investigated samples was performed, including mercury and chlorine content. The alternative fuel produced from used textiles will be characterized by acceptable parameters for consumers: a lower heating value at 20 MJ/kg (class 1-3 SRF), mercury content below 0.9 µg Hg/MJ (class 1 SRF), and a chlorine content below 0.2% (class 1 SRF). However, the very high sulfur content in wool (3.0-3.6%) and the high nitrogen content in acrylic may limit its use for power generation. The use of alternative fuel derived from used textiles may allow 3% of the coal consumed to be substituted in 2030. The reduction in carbon dioxide emissions from the substitution of coal with an alternative fuel derived from used textiles will depend on their composition. For natural and man-made cellulosic fibers, the emission factor can be assumed as for plant biomass, making their use for SRF production preferable. For synthetic fibers, the emission factor was estimated at the level of 102 and 82 gCO2/MJ for polyester and acrylic, respectively.

Polymer composite materials based on a binder from renewable raw materials: the effect of a filler on the physical and mechanical properties

Polymer composite materials have been developed using polyester-urethane-acrylate resin based on 2,5-furandicarboxylic acid obtained from plant biomass and a number of synthetic (carbon, glass, and aramid fibers) and mineral (basalt) fibrous fillers. The high operational characteristics of the obtained PCMs are demonstrated. The effect of hybridization of synthetic fibers with natural cellulose fibers (cotton) on the physical and mechanical properties of polymer composite materials has been studied. An increase in tensile strength with a simultaneous decrease in the density of PCM using a carbon fi ber/cotton hybrid filler is shown.