Green and facile synthesis of cellulose nanofibres from Peltophorum pterocarpum pods cellulose using a eutectic solvent

The physical properties, such as the fibre dimension and crystallinity, of cellulose nanofibre (CNF) are significant to its functional reinforcement ability in composites. This study used supercritical carbon dioxide as a fibre bundle defibrillation pretreatment for the isolation of CNF from bamboo, in order to enhance its physical properties. The isolated CNF was characterised through zeta potential, TEM, XRD, and FT-IR analysis. Commercial CNF was used as a reference to evaluate the effectiveness of the method. The physical, mechanical, thermal, and wettability properties of the bamboo and commercial CNF-reinforced PLA/chitin were also analysed. The TEM and FT-IR results showed the successful isolation of CNF from bamboo using this method, with good colloidal stability shown by the zeta potential results. The properties of the isolated bamboo CNF were similar to the commercial type. However, the fibre diameter distribution and the crystallinity index significantly differed between the bamboo and the commercial CNF. The bamboo CNF had a smaller fibre size and a higher crystallinity index than the commercial CNF. The results from the CNF-reinforced biocomposite showed that the physical, mechanical, thermal, and wettability properties were significantly different due to the variations in their fibre sizes and crystallinity indices. The properties of bamboo CNF biocomposites were significantly better than those of commercial CNF biocomposites. This indicates that the physical properties (fibre size and crystallinity) of an isolated CNF significantly affect its reinforcement ability in biocomposites. The physical properties of isolated CNFs are partly dependent on their source and production method, among other factors. These composites can be used for various industrial applications, including packaging.

Ultra-Strong, Ultra-Tough, Transparent, and Sustainable Nanocomposite Films for Plastic Substitute

A comparative study on properties of micro and nanopapers produced from cellulose and cellulose nanofibres.

Recycled polylactic acid (PLAr) was reinforced with treated nanocellulosic hemp fibers for biocomposite fabrication. Cellulosic fibers were extracted from hemp fibers chemically and treated enzymatically. Treated nanocellulosic fibers (NCF) were analyzed by Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Biocomposite fabrication was done with PLAr and three concentrations of treated NCF (0.1%, 0.25%, and 1% (v/v)) and then studied for thermal stability and mechanical properties. Increased thermal stability was observed with increasing NCF concentrations. The highest value for Young’s modulus was for PLAr + 0.25% (v/v) NCF (250.28 ± 5.47 MPa), which was significantly increased compared to PLAr (p = 0.022). There was a significant decrease in the tensile stress at break point for PLAr + 0.25% (v/v) NCF and PLAr + 1% (v/v) NCF as compared to control (p = 0.006 and 0.002, respectively). No significant difference was observed between treatments for tensile stress at yield.

Preparation and characterization of whey protein isolate/polydextrose-based nanocomposite film incorporated with cellulose nanofiber and L. plantarum: A new probiotic active packaging system

Amyloid β-peptide (Aβ) is a key molecule in Alzheimer’s disease (AD). Reliable immunohistochemical (IHC) methods to detect Aβ and Aβ-associated factors (AAF) in brain specimens are needed to determine their role in AD pathophysiology. Formic acid (FA) pre-treatment, which is generally used to enable efficient detection of Aβ with IHC, induces structural modifications within the Aβ, as well as in AAF. Consequently, interpretation of double IHC stainings becomes difficult. Therefore, serial stainings of two newly produced monoclonal antibodies (mAbs) VU-17 and IC16 and two other mAbs (6E10 and 3D6) were performed with four different pre-treatments (no pre-treatment, Tris/EDTA, citrate and FA) and additionally six IHC characteristics were scored: diffuse/compact/classic plaques, arteries with cerebral Aβ angiopathy, dyshoric angiopathy, capillaries with dyshoric angiopathy. Subsequently, these stainings were compared with IHC procedures, which are frequently used in a diagnostic setting, employing mAbs 4G8 and 6F/3D with FA pre-treatment. IHC Aβ patterns obtained with VU-17 and, IC16 and 3D6 without the use of FA pre-treatment were comparable to those obtained with 4G8 and 6F/3D upon FA pre-treatment. Omission of FA pre-treatment gives the advantage to allow double IHC stainings, detecting both Aβ and AAF that otherwise would have been structural modificated upon FA pre-treatment.

Cellulose nanofibers (CNF) have been applied in composite systems due to the abundance of raw material, excellent mechanical and thermal properties. In this work, CNF was prepared from agroindustrial waste and used in specified amounts in polyvinyl alcohol (PVA) composites. The FTIR spectra of CNF, chemically purified cellulose (CPC) and Cassava Agro-industrial Waste (CAW) indicate the removal of hemicellulose and lignin. The increase of the crystallinity phase in CNF was observed, by XRD analysis and neither is observed the transition from cellulose I to II. Thermogravimetric analysis showed displacement that the initial degradation of the CNF over 43 °C degradation proceeds at single step. The chemical and dimensional homogeneity of CNF can be observed with the calculation of the crystalline phase content obtained by deconvoluted dTG curve and XRD spectra, obtaining 80% crystallinity by both techniques. SEM micrographs showed fibers with diameters of 22.30 ± 1.52 nm. An increase in the mechanical properties of PVA was observed with the addition of CNF. With 2.5% CNF in the PVA, the elastic module increased by approximately three times, with the addition of 10% CNF, a saturated system with poor mechanical properties was observed.

Conversion of agro-waste to value-added products is one of the important principles of a green circular economy. A novel sustainable technique has been reported by using chlorine-free extraction of cellulose nanofibers (CNFs) from the peels of Salacca zalacca, a common fruit found in Asia. The fruit peels were exposed to alkali treatment using 2% NaOH (60 °C, 2 h), chlorine-free bleaching using 15% hydrogen peroxide (60 °C, 2 h), and sulfuric acid hydrolysis (15% v/v) for the extraction of CNFs. Various analytical methods were employed to characterize the prepared CNFs. The Fourier transform infrared spectroscopy (FTIR) and 13C solid state nuclear magnetic resonance (NMR) spectra showed the complete elimination of lignin and hemicellulose in the prepared CNFs. The elemental composition and high purity of CNFs were further verified by energy-dispersive X-ray analysis (EDX). The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images proved the fibrous morphology of the prepared CNFs, and the diameters of the cellulose nanofibers were found to be 15-30 nm. The X-ray diffraction (XRD) studies disclosed the type-I cellulosic structure in the prepared CNFs with a high crystallinity index (73%). The thermogravimetric analysis (TGA) demonstrated the superior thermal stability of the prepared CNFs (T max is 350 °C) compared to the raw fiber (T max is 320 °C). Based on the obtained results, it has been explored that the extracted highly pure CNFs can be used for fabricating bionanocomposites for high performance applications, including food packaging, sensors, water treatment, green tires, etc.

Seaweed has garnered global attention for its applications in sustainable materials, owing to its renewable and biodegradable nature. This study investigated the incorporation of cellulose nanofiber (CNF) into raw seaweed (RS) and semi‐refined carrageenan (SRC) biofilms to evaluate its impact on their structural, thermal, and mechanical properties. CNF, characterized by a high aspect ratio and zeta potential (−38.9 mV), demonstrated enhanced interfacial bonding and dispersion stability within the biofilm matrix. FT‐IR spectroscopy confirmed CNF's integration, while XRD analysis highlighted its high crystallinity, contributing to effective reinforcement. The addition of CNF significantly improved the tensile strength, modulus, and elongation at break, with optimal performance at 5% CNF loading. Beyond this, mechanical properties declined due to CNF agglomeration, as observed in SEM micrographs, which showed microcracks and rougher surfaces at higher loadings. Thermal stability, assessed via TGA, improved with CNF loading, with SRC biofilms demonstrating superior resistance to thermal degradation compared to RS biofilms. These findings indicate that CNF‐reinforced RS and SRC biofilms, particularly at 5% CNF loading, offer enhanced mechanical and thermal properties, positioning them as promising materials for sustainable packaging. Further optimization could broaden their applications in industries such as biomedicine and food preservation.Highlights RS and SRC biofilms explored as eco‐friendly plastic packaging materials. CNF loading enhances biofilm properties for RS and SRC‐based films. SRC biofilms exhibit improved flexibility and durability over RS biofilms. Optimal CNF loading (1%–5%) enhances thermal stability of SRC biofilms. Crack resistance in SRC biofilms confirms strong CNF‐carrageenan structure.

Thermoplastic starch nanocomposites using cellulose-rich Chrysopogon zizanioides nanofibers

The duration of formic acid (FA) pretreatment clearly influences the extent of beta-amyloid immunoreactivity in brain tissue and consequently also the results of quantitative analysis. All of the parameters studied (area fraction, density, and mean size of beta-amyloid deposits) significantly increased with pretreatment of up to 6 h with beta-amyloid antibody obtained from Dako. Longer exposure to FA only marginally increased the mean size of the single deposits, whereas the area fraction and the density of beta-amyloid deposits slightly decreased. Optimal 6-h pretreatment (or even longer) did not reveal any beta-amyloid aggregates in those cases where none was seen with shorter durations of FA pretreatment. Similar results were obtained with beta-amyloid antibody 4G8 obtained from Senetek, whereas beta-amyloid antibody 6E10 was shown to be less dependent upon FA pretreatment. In conclusion, we recommend that the FA pretreatment time should be studied and optimized for each antibody used and always be described when the quantitative analysis of beta-amyloid load is reported.

Cellulose nanofibers (CNFs) are highly crystalline, fibrous materials with a high aspect ratio of long cellulose molecules linked together with strong hydrogen bonds. These long cellulose molecules are incorporated into hemicellulose and lignin, the cell walls of higher plants. The modulus of elasticity of CNF remains constant between −200 °C and +200 °C. However, the linear coefficient of thermal expansion of cellulose fibers was 0.17 ppm/K, which is comparable to that of quartz glass. Further, CNFs have a thermal conductivity in the same order of magnitude as glass. Therefore, they are promising next-generation fiber owing to the excellent mechanical and thermal properties, sustainability, and biodegradability of CNF. Most studies on using CNFs to increase strength have focused on polymer matrix composites, particularly biodegradable polymers. However, it is difficult to increase the strength of materials using CNFs due to the agglomeration of CNFs. Compared to other composite materials, the uniform dispersion of nanosized CNFs is crucial. This article reports that CNFs may behave not as reinforcing fibers but as cross-linking agents to strengthen the polymer when the amount of CNFs is very small in polymer matrix composites, and the addition of CNFs is also effective in strengthening silk yarn and Ti. The mechanical properties of the ceramic green bodies can be increased using CNFs as an auxiliary agent in ceramic slurry. Moreover, the fabrication of composite materials using CNFs is essential for expanding the CNFs applications.

The extraction of cellulose nanofibers (CNFs) from lignocellulosic biomass provides a sustainable alternative to synthetic materials due to their biodegradability, mechanical strength, and environmental compatibility. However, conventional extraction methods are often affected by high chemical consumption, energy intensity, and limited scalability. This study presents a comparative and optimized approach for the sustainable extraction of CNFs using two distinct methods, including chemo-mechanical treatment and Soxhlet extraction, applied to sugarcane bagasse and eucalyptus bark. Unlike previous studies, this work systematically compares both methods under controlled conditions to evaluate their efficiency, fiber integrity, and environmental impact. The extracted CNFs were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), and zeta potential analysis. The FTIR spectra confirmed the presence of C–O–C fundamental vibrational stretching of cellulose and effective removal of non-cellulosic components such as lignin and hemicellulose. XRD results displayed the moderate crystalline nature of the extracted cellulose, with variation in intensity attributed to extraction technique and biomass type. Zeta potential analysis showed that CNFs extracted from eucalyptus bark via Soxhlet extraction exhibited superior colloidal stability (−32.5 mV), while those from sugarcane bagasse through chemo-mechanical treatment showed lower stability (−15.3 mV). These findings offer new insights into the method-material interaction and highlight the Soxhlet extraction route as more effective in producing stable, high-purity nanofibers. The protocols can be vital in reducing production costs and chemical utilization, enhancing material performance, and enabling large-scale application in packaging and biomedical industries.

Towards the development of anti-infective nanoscale materials employing a photodynamic mechanism of action, we report the synthesis, physical properties (SEM, mechanical strength, water contact angle), spectroscopic characterization (infrared, Raman, DRUV), and evaluation of antibacterial efficacy of porphyrin-conjugated regenerated cellulose nanofibers, termed RC-TETA-PPIX-Zn. Cellulose acetate was electrospun to produce nanofibers, thermally treated to enhance mechanical strength, and finally hydrolyzed to produce regenerated cellulose (RC) nanofibers that possessed a high surface area and nanofibrous structure. Covalent grafting of a protoporphyrin IX (PPIX) photosensitizer using epichlorohydrin/triethylenetetramine (TETA), followed by zinc chelation, afforded RC-TETA-PPIX-Zn. The high surface area afforded by the nanofibers and efficient photosensitizer conjugation led to a very high loading of 412 nmol PPIX/mg material, corresponding to a degree of substitution of 0.1. Antibacterial efficacy was evaluated against Staphylococcus aureus (ATCC-6538) and Escherichia coli (ATCC-8099), with our best results achieving detection limit inactivation (99.999+%) of both bacteria after only 20 min illumination (Xe lamp, λ ≥ 420 nm). No statistically significant loss in antibacterial activity was observed when using nanofibers that had been ‘photo-aged’ with 5 h of pre-illumination to simulate the effects of photobleaching. Post aPDI, scanning electron microscopy revealed that the bacteria had undergone cell membrane leakage, consistent with oxidative damage caused by photo-generated reactive oxygen species. Taken together, the conjugation strategy employed here provides a scalable, facile and efficient route to creating nanofibrous materials from natural polymers with a high photosensitizer loading, enabling the use of commercially-available neutral porphyrin photosensitizers, such as PPIX, in the design and synthesis of potent anti-infective nanomaterials.

Starch based Active Packaging Film Reinforced with Empty Fruit Bunch (EFB) Cellulose Nanofiber