Cellulose Fiber Size Research Articles

Effect of different electronegative oxygen atoms of cellulose nanofibrils on the formation and photocatalytic property of ZnO/cellulose composite

Cellulose is widely employed as a template in supporting and dispersing ZnO. The oxygen atom of the hydroxyl (–OH) groups of cellulose have a significant impact on the morphology and photocatalytic property of ZnO. This work aims to investigate the effect of different electronegative oxygen atoms of cellulose nanofibrils (CNF) on the formation and photocatalytic properties of ZnO/cellulose composites. The interaction between cellulose and ZnO has been achieved by controlling cellulose fiber size and regulating the electronegativity of oxygen atoms on the CNF surface. The results indicate that etherized CNF (ECNF) with the highest degree of etherification substitution (1.7) and the best electronegativity (−34.6 mV) can synthesize the ZnO/cellulose composite with the largest loading content of ZnO (58.9%) and the best photocatalytic activity for MO degradation (91.1%). It can be concluded that the intenser electrostatic interaction between oxygen atoms on the CNF surface and ZnO can facilitate the fixation and growth of more high-quality ZnO nanoflowers, thus improving the photocatalytic property. In a word, this work can provide a novel perspective for the efficient preparation of ZnO/cellulose composites with designable morphology and structure.

Cellulose-based Material for Sound Absorption And Its Application – A Short Review

Cellulose is a natural fiber potentially used as a sound absorber material due to its excellent properties, biodegradability, and lower environmental impact than synthetic materials and can be sourced from various plant-based materials, such as wood, Cotton, and Hemp. Which effectively traps and absorbs sound waves. The fibers dissipate the energy of sound waves as they pass through the material and absorb sound energy across a wide range of frequencies. Cellulose can be installed as loose-fill insulation, rigid panel form, composite with other matrix material, or foam. It's important to note that the specific characteristics and performance of cellulose-based sound absorbers can vary depending on the manufacturing process, fiber treatment, and the overall design of the sound-absorbing material. The size of cellulose fibers used in sound absorption can impact their effectiveness. Microfiber and nanofiber cellulose show different sound absorption characteristics. Microfiber has a good absorption coefficient at lower frequencies, and nanofiber cellulose performs better at higher frequency ranges. This paper involves a shortreview study of experimental methods and parameters used to regulate cellulose's sound absorption performance, which seems to be a potential alternative as an acoustic absorber, thereby reducing sustainability concerns related to synthetic materials in acoustics applications.

Construction of Ag–ZnO/cellulose nanocomposites via tunable cellulose size for improving photocatalytic performance

The Ag–ZnO/cellulose nanocomposites with tunable structure and properties was fabricated and used as an effective photocatalyst for degrading methyl orange (MO) dye. The structure and properties of the Ag–ZnO/cellulose nanocomposites were regulated by the cellulose fiber size via different times of grinding treatment. The morphologies of ZnO NPs changed from flower-like to flaky with the decrease of diameter of cellulose fiber from 130 nm to 42 nm, and loading amounts of ZnO and Ag NPs on photocatalyst increased from 56.12% to 57.46% and 5.28%–6.54% respectively. The finer fibrils provided a more uniform network compared with coarse fibers, which is benefit for stable distribution of ZnO and Ag nanoparticles (NPs) and facile separation from wastewater. The Ag–ZnO/cellulose nanocomposites, prepared from cellulose fiber with grinding treatment of 30 times, exhibited homogeneous three-dimensional cellulose network with specific surface area of 40.64 m2/g and possessed excellent photocatalytic activities and reusability for MO degradation. This work provided a novel approach to control the morphology of ZnO by tuning cellulose size, for improving photocatalytic activities and recovery efficiency of Ag–ZnO/cellulose nanocomposites.

Structural, Morphological and Thermal Properties of Cellulose Nanofibers from Napier fiber (Pennisetum purpureum)

The purpose of the study is to investigate the utilisation of Napier fiber (Pennisetum purpureum) as a source for the fabrication of cellulose nanofibers (CNF). In this study, cellulose nanofibers (CNF) from Napier fiber were isolated via ball-milling assisted by acid hydrolysis. Acid hydrolysis with different molarities (1.0, 3.8 and 5.6 M) was performed efficiently facilitate cellulose fiber size reduction. The resulting CNFs were characterised through Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), particle size analyser (PSA), field-emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The FTIR results demonstrated that there were no obvious changes observed between the spectra of the CNFs with different molarities of acid hydrolysis. With 5.6 M acid hydrolysis, the XRD analysis displayed the highest degree of CNF crystallinity at 70.67%. In a thermal analysis by TGA and DTG, cellulose nanofiber with 5.6 M acid hydrolysis tended to produce cellulose nanofibers with higher thermal stability. As evidenced by the structural morphologies, a fibrous network nanostructure was obtained under TEM and AFM analysis, while a compact structure was observed under FESEM analysis. In conclusion, the isolated CNFs from Napier-derived cellulose are expected to yield potential to be used as a suitable source for nanocomposite production in various applications, including pharmaceutical, food packaging and biomedical fields.

Oleogelation of rapeseed oil with cellulose fibers as an innovative strategy for palm oil substitution in chocolate spreads

Abstract The texturing properties of mercerized cellulose dispersed in rapeseed oil without any prior thermal treatment were investigated as a function of botanical origin, cellulose content, mass fraction and fiber size through a molecular analysis of samples, macroscopic/microscopic observations and rheological experiments (continuous and oscillatory shear flows). A solid-like behavior of dispersions was demonstrated for a minimum cellulose content of about 60wt% in the vegetal powder. The oleogelation efficiency increases with the mass fraction of powder in oil and the maximum size of cellulose fibers as a result of weak attractive interactions and fiber entanglement giving rise to a network entrapping the liquid phase. An innovative strategy using a 30wt% dispersion of bamboo fibers in rapeseed oil was finally used to produce in a conch a chocolate spread with a high thermal stability at 38°C and healthier nutritional qualities compared to an equivalent product prepared with palm oil.

One-step twin-screw extrusion process of cellulose fibers and hydroxyethyl cellulose to produce fibrillated cellulose biocomposite

In this work, the defibrillation of cellulose fibers (CF) in the presence of hydroxyethyl cellulose (HEC) within the one-step twin-screw extrusion (TSE) process was examined. The effect of the TSE on cellulose fiber size reduction as well as CF-HEC biocomposites properties were investigated. The results showed that the TSE of cellulose fiber-hydroxyethyl cellulose (CF-HEC) with different cellulose fiber contents (50, 65, and 80 wt%) resulted in partial defibrillation of the cellulose fibers. The fractionation test of the cellulose fibers confirmed that their size was reduced and some fibrillation was observed in microscopy studies. The maximum width reduction of 46% occurred with 80 wt% cellulose content. However, the partial width reduction was also observed with 50% and 65 wt% of cellulose contents. Based on rheological measurements, the shear-viscosity trend of CF-HEC dispersion abruptly dropped when higher fiber content (80 wt%) was extruded, which was related to the fibrillation of the cellulose fibers as well as the reduction of the length. The extruded CF-HEC materials (powder form) were compression molded to prepare the biocomposites with different cellulose fiber contents (50, 65, and 80 wt%). The extruded CF-HEC powders were diluted with addition extra HEC to make biocomposites with lower fiber content (20%, 30%, and 40 wt%) and compression molded to study how the size reduction of the cellulose fibers affected the mechanical properties of biocomposites. The results showed that the E-modulus improved from 0.4 GPa of the neat HEC to 1.6 GPa for the composite with 40 wt% CF. Interestingly, the tensile strength of CF-HEC biocomposite with 40 wt% confirmed a clear improvement from 9.8 to 26.6 MPa, confirming good interaction between HEC and CF.Graphic abstract Preparation (mixing, TSE, and hot-pressing) and characterization (FE-SEM, rheometry, and tensile test) of CF-HEC biocomposite

Water‐Resistant and Haze‐Tunable Transparent Cellulose Nanopaper for Patterned Electroluminescence Devices

AbstractA water‐resistant cellulose nanopaper with thermal stability (290 °C is decomposition temperature) and higher fracture strength (127 MPa maximum) than polyethylene terephthalate film is demonstrated. The extraordinary swelling ability of dimethyl sulfoxide for cellulose is used to decrease the size of cellulose fibers. A highly transparent (93% at a wavelength of 550 nm for a 100 µm thick nanopaper) and haze‐tunable (from 5.5% to 41.5% at a wavelength of 600 nm) nanopaper is obtained. Additionally, the water‐resistant cellulose nanopaper is further used as a flexible transparent substrate for patterned electroluminescence devices, revealing that this cellulose nanopaper holds great promise for electronic devices.

Cellulose fiber size defines efficiency of enzymatic hydrolysis and impacts degree of synergy between endo- and exoglucanases

An interplay between cellulases is fundamental in biomass saccharification. Here, the synergistic action of Trichoderma harzianum Cel7A and Cel7B on two cellulosic substrates: bacterial cellulose (BC) and a much more heterogeneous filter paper (FP) was investigated by determining their saccharification yields and by analyzing both the released soluble products and the insoluble reducing ends formed in the process. Furthermore, morphological changes of the substrates were evaluated using scanning electron microscopy. Glycoside hydrolase family 7 (GH7) enzymes introduce uniform changes in BC, whereas in FP they preferentially consume thin microfibrils rather than thicker paper fibers. Thus, the size effect, which leads to a smaller surface area per unit of substrate mass for thicker fibers, seems to play a crucial role in higher enzymatic hydrolysis efficiency of BC as compared to FP. These results demonstrate that the morphology-dependent effects could be essential for the industrial breakdown of cellulose-rich plant biomass.

Waterproof Active Paper via Laser Surface Micropatterning of Magnetic Nanoparticles

Paper is one of the oldest and most abundant materials known to man. Recently, there has been a considerable interest in creating paper devices by combining paper with other functional materials. In this letter, we demonstrate a simple fabrication technique to create water-resistant ferro-patterns on wax paper using CO(2) laser ablation. A resolution of about 100 μm is achieved which is mostly limited by the cellulose fiber size (~50 μm) in the wax paper and can be improved by using a smaller cellulose matrix. Laser ablation results in modification of surface morphology and chemistry, leading to a change in surface energy. We also present a 2D model for ferrofluid deposition relating the size of the pattern to the amount of ferroparticles deposited on the surface. Finally, a paper gripper is presented to demonstrate advantages of our technique, which allows microscale patterning and machining in a single step.

Size effects of cellulose nanofibers for enhancing the crystallization of poly(lactic acid)

AbstractA desirable size of cellulose fibers for enhancing the crystallization of poly(lactic acid) (PLA) in composites was investigated by comparison among cellulose nanofibers with different widths on nanoscales. Namely, the crystallization behaviors of PLA in the presence of cellulose nanofibers were monitored with differential scanning calorimetry and polarized optical microscopy in terms of the crystallization rates of PLA. The smallest width of cellulose nanofibers was found to not necessarily provide better enhancement for the crystallization, presumably because of the preferential self‐assembly of smaller cellulose nanofibers in PLA. Namely, when the width was smaller, the better effect expected for nanofibers did not appear in the composites. It is possible that an optimum width range of 60 nm, more or less, in the cellulose nanofibers may exist in balance between the favorable self‐assembly as an enthalpy effect and the tendency toward dispersion as an entropy effect. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Miniaturization of cellulose fibers and effect of addition on the mechanical and barrier properties of hydroxypropyl methylcellulose films

Cellulose fibers were miniaturized by microfluidics technology to decrease their size and incorporated in hydroxypropyl methylcellulose (HPMC) films to study the effect of addition of such fibers on the mechanical and barrier properties of HPMC films suitable for application in food packaging. The particle size of fibers and the mechanical properties, water vapor and oxygen permeabilities, total pore volume, and light and electron microscopy micrographs of films were analyzed. Incorporation of cellulose fibers in the films improved their mechanical and barrier properties significantly. This study is the first to investigate the use of microfluidics technology for the purpose of decreasing the size of cellulose fibers and the addition of reduced size microfibers to improve physical properties of HPMC films.