Properties Of Nanocellulose Research Articles

Fabrications of cellulose nanocomposite for tailor-made applications

The unique properties of nanocelluloses (NCs), including nanodimension, renewability, low toxicity, biocompatibility, biodegradability, easy availability, and low cost, render them the ideal nanomaterials for diverse applications. Composite material consists of matrix material with low volume fraction and self-assembled NC fibers with a high volume fraction of reinforcing domain. These two-phase components are often combined to promote stiffness and improve toughness (by dissipating materials fracture energy). The challenge, however, is to control the alignment and distribution of NC within the matrix. Recent research has been focusing on the production of composites using different methodologies such as electrospun cellulose nanofibers, polymer-grafted NC, nanoparticle binding on NCs, assembly of NCs at the air/water and oil/water interfaces, protein-mediated interactions on NCs, and atomic layer deposition on NCs. In this case, NC serves as an appropriate candidate for composites preparation in comparison to the non-biodegradable nanofillers (e.g. carbon nanoclay and nanotube).

Nanocellulose Reinforced Flexible Composite Nanogenerators with Enhanced Vibrational Energy Harvesting and Sensing Properties

We report here enhanced vibration and pressure sensing properties of nanocellulose reinforced flexible composite piezoelectric nanogenerators (PENGs). Surface fluorinated nanocellulose crystals (FN...

A new approach for the use of anionic surfactants: nanocellulose modification and development of biodegradable nanocomposites

The stabilization of nanocellulose suspensions and their compatibility with polymer matrices are challenges that have been investigated in the scientific community. However, little work has resulted in significant electrostatic stabilization as well as improved the mechanical behavior of nanocomposites. Anionic surfactant modified nanocellulose, and the results demonstrated the impact of the concentration of this surfactant on nanocellulose surfaces and properties. The variation in electrostatic stability was evaluated by the zeta potential, which is key to the comprehension of dispersion and agglomeration in suspensions. Also, physicochemical tests were conducted to analyze the properties of nanocelluloses. The addition of the surfactant and its effects were verified by physicochemical characterization; it was evaluated the crystallinity, thermal stability, composition, adsorption effect, and other properties. Mechanical, thermal and physicochemical tests were conducted to understand the influence of nanoparticles on nanocomposites. The results of this study demonstrated that the surfactant-modified cellulose nanostructures presented excellent electrostatic and thermal stability, which made the developed materials potential reinforcing agents for the incorporation of polymeric matrices. These modified CNSs were incorporated in a poly(butylene adipate-co-terephthalate), and improvements of its mechanical properties were observed. Also, the thermal stability of the polymer was maintained, and the water diffusion coefficient was reduced, favoring applications that need this characteristic, like plastic packaging.

Nanocellulose from recycled indigo-dyed denim fabric and its application in composite films

In this study, nanocellulose was extracted from indigo-dyed denim fabric and the resultant nanocellulose properties were evaluated in comparison with those derived from bleached cotton fabric and wood pulp in order to investigate the potential of recycling denim waste for nanocellulose production and application. Sulfuric acid hydrolysis and (2,2,6,6-tetramethylpiperidin-1-yl) oxyl (TEMPO)-oxidation were utilized to produce cellulose nanocrystals (CNC) and cellulose nanofibers (TOCN), respectively. A stable CNC suspension with blue color was obtained after acid hydrolysis and the TEMPO process yielded colorless TOCN. The denim-derived nanocellulose possessed similar yield, morphology, size, crystallinity, and thermal stability to those derived from bleached cotton but higher crystallinity and thermal stability compared to the nanocellulose from wood pulp. When used to reinforce polyvinyl alcohol film, the blue indigo-CNC not only enhanced mechanical properties of the film but also provided the film with outstanding UV blocking.

Functional Materials from Nanocellulose: Utilizing Structure-Property Relationships in Bottom-Up Fabrication.

It is inherently challenging to recapitulate the precise hierarchical architectures found throughout nature (such as in wood, antler, bone, and silk) using synthetic bottom-up fabrication strategies. However, as a renewable and naturally sourced nanoscale building block, nanocellulose-both cellulose nanocrystals and cellulose nanofibrils-has gained significant research interest within this area. Altogether, the intrinsic shape anisotropy, surface charge/chemistry, and mechanical/rheological properties are some of the critical material properties leading to advanced structure-based functionality within nanocellulose-based bottom-up fabricated materials. Herein, the organization of nanocellulose into biomimetic-aligned, porous, and fibrous materials through a variety of fabrication techniques is presented. Moreover, sophisticated material structuring arising from both the alignment of nanocellulose and via specific process-induced methods is covered. In particular, design rules based on the underlying fundamental properties of nanocellulose are established and discussed as related to their influence on material assembly and resulting structure/function. Finally, key advancements and critical challenges within the field are highlighted, paving the way for the fabrication of truly advanced materials from nanocellulose.

Nanocellulose‐based polymer composites for energy applications—A review

ABSTRACTWith rapid fossil fuel consumption and ecological concerns, alternative options of green energy development and its efficient storage technology is an emergent area of research. Nanocellulose is observed to be a very‐promising sustainable and environmentally friendly nanomaterial for green and renewable electronics for advanced electrochemical energy conversion/conservation devices. This review begins with a basic introduction on the sources and properties of nanocellulose. It provides an overview of the recent advancements made by researchers in integrating nanocellulose with active materials to form a flexible film/aerogel/3D structures as a substrate for powering portable electronics, electric vehicles, etc. The review highlights the use of nanocellulose‐based composites in energy conversion devices such as solar cells, piezoelectric materials, and lithium ion batteries. Recent research shows that the power conversion efficiency of solar cells and the piezoelectric performance of piezoelectric materials can be increased when the matrix is reinforced with nanocellulose. The review also focuses on the updates of nanocellulose‐based composites in separators, binders, and electrodes of energy conservation devices such as supercapacitors, and energy capture devices such as CO2 separators. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48959.

Acidic and alkaline deep eutectic solvents in delignification and nanofibrillation of corn stalk, wheat straw, and rapeseed stem residues

In this work, six different deep eutectic solvent (DES) treatments—five acidic (natural organic acid–choline chloride) and one alkaline (K2CO3–glycerol)—were used and compared in delignification and nanofibrillation of agricultural by-products from wheat straw, corn stalk, and rapeseed stem. The DES treatments were performed at 100 °C for 8 h, at 100 °C for 16 h, and at 80 °C for 24 h. The yield of cellulose and lignin fractions was obtained gravimetrically, and a more detailed composition of fractions was obtained for the 16 h treatment. All the samples were further nanofibrillated, and the properties of nanocelluloses and their nanopapers were measured. Acidic lactic acid–choline chloride and alkaline K2CO3–glycerol DESs resulted in the highest delignification yields (11.8–5.7 wt-%), nanocellulose viscosity (1360–555 Pa s), and crystallinity index (54–38 %), but the strength properties of nanopapers from alkaline DES treatment (170–132 MPa) were better compared to acidic DESs (132–24 MPa). A plausible explanation for this difference may be that the alkaline DES also dissolved waxes and proteins, which can mitigate the adhesion and network formation between the nanofibers. It was also observed that the separated lignin fractions from acidic and alkaline DES treatments had different characteristics as determined by FTIR.

Top-down peeling bacterial cellulose to high strength ultrathin films and multifunctional fibers

• BC nanofiber alignment was achieved via a simple one-step solvent-assisted drawing. • It is the first time to realize the peeling of BC film layer by layer to obtain BC ultrathin film. • The ultrathin film simultaneously exhibited high tensile strength (758 MPa) and high toughness (42.3 MJ m −3 ). • The BC ultrathin film can be twisted to super strong fibers or multifunctional fibers. • The fiber exhibited high tensile strength (954.2 MPa) and the record high toughness (93.2 MJ m −3 ). The materials with highly aligned tight arrangement at nano- and molecular level exhibit extraordinary mechanical properties. Bacterial cellulose (BC) is a three-dimensional network hydrogel formed by layers of disordered nanofibers generated by bacteria. Because of the disordered arrangement of nanofibers and the strong interaction between nanofibers, it is impossible for BC to give full play to the excellent mechanical properties of nanocellulose. In this paper, we first adopted an easily realized method to obtain high strength BC ultrathin film with highly aligned tight nanofiber structure. First, the hydrogen bond between nanofibers was weakened by simple solvent replacement, and then we stretched the BC hydrogel to 20−40% to realize the nanofiber alignment. After by hot-pressing drying, we first realized the peeling of BC film layer by layer to obtain the high strength ultrathin films inspired by graphene peeling method. The highest strength of the obtained film with thickness of 4–10 µm was up to 758 MPa and the toughness up to 42.3 MJ m −3 . By further twisting the films, very strong and tough fibers were obtained with high strength of 954.2 MPa and the record high toughness of 93.2 MJ m −3 . Furthermore, functional BC fibers can be achieved by embedding functional materials (dyes, functional nanomaterials, carbon nanotubes, etc.) in the ultrathin films before twisting. Our research first realized the transformation from BC hydrogel to ultrathin films and fibers with high strength and toughness. This work will pave the way for the application of BC hydrogel as high-strength flexible electronic device substrates, medical fibers, and wearable electronics.

Modification of bacterial nanocellulose properties through mutation of motility related genes in Komagataeibacter hansenii ATCC 53582

Bacterial nanocellulose (BNC) produced by Komagataeibacter hansenii has received significant attention due to its unique supernetwork structure and properties. It is nevertheless necessary to modify bacterial nanocellulose to achieve materials with desired properties and thus with broader areas of application. The aim here was to influence the 3D structure of BNC by genetic modification of the cellulose producing K. hansenii strain ATCC 53582. Two genes encoding proteins with homology to the MotA and MotB proteins, which participate in motility and energy transfer, were selected for our studies. A disruption mutant of one or both genes and their respective complementation mutants were created. The phenotype analysis of the disruption mutants showed a reduction in motility, which resulted in higher compaction of nanocellulose fibers and improvement in their mechanical properties. The data strongly suggest that these genes play an important role in the formation of BNC membrane by Komagataeibacter species.

State-of-the-Art of Cellulose Nanocrystals and Optimal Method for their Dispersion for Construction-Related Applications

In this paper, we reviewed the existing literature on the fabrication of nanocomposites based on cellulose and cellulose nanocrystals (CNCs), and analyzed their dispersion mechanism with respect to their use in the field of construction. First, the existing literature on CNC-based nanocomposites that exhibit the physical and chemical properties of nanocellulose and CNCs was reviewed. Next, keeping the use of these nanocomposites in the field of construction in mind, we determined the optimal mechanical method for their dispersion as an alternative to the currently used harmful chemical techniques. To this end, we evaluated the dispersibility of colloidal CNCs using two dispersion methods: magnetic stirring (for stirring times of 60 min, 120 min, and 180 min) and high-pressure dispersion (at pressures of 345 × 105 Pa, 1035 × 105 Pa, and 1587 × 105 Pa, and one to three dispersion passes). The optimal dispersion conditions were determined by analyzing the size and zeta potential of the CNC particles. It was found that the difference in the average diameter was reduced by approximately 76% at 1587 × 105 Pa during high-pressure dispersion.

GVL pulping facilitates nanocellulose production from woody biomass

Nanocellulose was extracted from wood by green GVL pulping without bleaching, but with no impact on the properties of nanocellulose.

Investigation of mechanical properties of nanocellulose reinforced synthetic polymer composite

In Sri Lanka, a considerable percentage of agricultural waste such as rice straw and sugarcane bagasse is discharged to the environment without a commercial use and forms a huge organic environmental pollution. Therefore, the agricultural wastes can be used to extract cellulose and indirectly apply an additional value to the abundant priceless wastes. Nanocellulose is a cellulosic material which has at least one dimension in the nanometre range and has a potential for polymer reinforcement. Based on their structure nanocellulose extracted from plant species are categorised into two; nanofibrillated cellulose (NFC) and nanocrystalline cellulose (NCC). The present paper discussed the surface modification of NFC using Silane coupling agent (Si-69) and fabrication of silylated NFC reinforced polypropylene (PP) composites with different loadings of NFC from 0-5 wt. % by adding 0.5 wt. % per sample. The mechanical properties of the composite samples were compared with respect to neat PP and Scanning electron microscope (SEM), Fourier-transform infrared spectroscopy, X-ray diffraction, mechanical tests (tensile strength, percentage elongation at break, impact strength and hardness), percentage water absorption and melt flow index (MFI) were used to characterize the developed composites. The experimental results emphasize the wide improvement of mechanical properties with extremely narrow reduction of water absorption and processability of silylated NFC based PP than pure PP. The 3.5% silylated NFC reinforced PP composite indicated the highest improvement in mechanical properties such as hardness, tensile and impact strength, a 7.4%, 12.6%, and 86.1% higher than the neat PP, respectively.

Viscoelastic properties of nanocellulose based inks for 3D printing and mechanical properties of CNF/alginate biocomposite gels

Inks for 3D printing based on cellulose nanofibrils (CNFs) or mixtures of CNFs and either cellulose nanocrystals (CNCs) or alginate were assessed by determining their viscoelastic properties i.e. complex viscosity and storage and loss moduli (G′ and G″). Two types of alginates were used, i.e. from Laminaria hyperborea stipe and Macrocystis pyrifera. Shape fidelity of 3D printed grids were qualitatively evaluated and compared to the viscoelastic properties of the inks. The biocomposite gels containing alginate were post stabilized by crosslinking with Ca2+. Mechanical properties of the crosslinked biocomposite gels were assessed. The complex viscosity, G′ and G″ of CNF suspensions increased when the solid content was increased from 3.5 to 4.0 wt%, but levelled off by further increase in CNF solid content. The complex viscosity at low angular frequency at 4 wt% was as high as 104 Pa·s. This seemed to be the necessary viscosity level for obtaining good shape fidelity of the printed structures for the studied systems. By replacing part of the CNFs with CNCs, the complex viscosity, G′ and G″ were reduced and so was also the shape fidelity of the printed grids. The changes in complex viscosity and moduli when CNFs was replaced with alginate depended on the relative amounts of CNFs/alginate. The type of alginate (from either L. hyp. stipe or M. pyr.) did not play a role for the viscoelastic properties of the inks, nor for the printed grids before post stabilization. Replacing CNFs with up to 1.5 wt% alginate gave satisfactory shape fidelity. The effect of adding alginate and subsequent crosslinking with Ca2+, strongly affected the strength properties of the gels. By appropriate choice of relative amounts of CNFs and alginate and type of alginate, the Young’s modulus and rupture strength could be controlled within the range of 30–150 kPa and 1.5–6 kg, respectively. The deformation at rupture was around 55%. The alginate from L. hyp. stipe yields higher Young’s modulus and lower syneresis compared to M. pyr. This shows that the choice of alginate plays a significant role for the mechanical properties of the final product, although it does not influence on the viscoelastic properties of the ink. The choice of alginate should be L. hyp. stipe if high strength is desired.

Nanocellulose, a Versatile Green Platform: From Biosources to Materials and Their Applications

With increasing environmental and ecological concerns due to the use of petroleum-based chemicals and products, the synthesis of fine chemicals and functional materials from natural resources is of great public value. Nanocellulose may prove to be one of the most promising green materials of modern times due to its intrinsic properties, renewability, and abundance. In this review, we present nanocellulose-based materials from sourcing, synthesis, and surface modification of nanocellulose, to materials formation and applications. Nanocellulose can be sourced from biomass, plants, or bacteria, relying on fairly simple, scalable, and efficient isolation techniques. Mechanical, chemical, and enzymatic treatments, or a combination of these, can be used to extract nanocellulose from natural sources. The properties of nanocellulose are dependent on the source, the isolation technique, and potential subsequent surface transformations. Nanocellulose surface modification techniques are typically used to introduce either charged or hydrophobic moieties, and include amidation, esterification, etherification, silylation, polymerization, urethanization, sulfonation, and phosphorylation. Nanocellulose has excellent strength, high Young's modulus, biocompatibility, and tunable self-assembly, thixotropic, and photonic properties, which are essential for the applications of this material. Nanocellulose participates in the fabrication of a large range of nanomaterials and nanocomposites, including those based on polymers, metals, metal oxides, and carbon. In particular, nanocellulose complements organic-based materials, where it imparts its mechanical properties to the composite. Nanocellulose is a promising material whenever material strength, flexibility, and/or specific nanostructuration are required. Applications include functional paper, optoelectronics, and antibacterial coatings, packaging, mechanically reinforced polymer composites, tissue scaffolds, drug delivery, biosensors, energy storage, catalysis, environmental remediation, and electrochemically controlled separation. Phosphorylated nanocellulose is a particularly interesting material, spanning a surprising set of applications in various dimensions including bone scaffolds, adsorbents, and flame retardants and as a support for the heterogenization of homogeneous catalysts.

Effects of the growth environment on the yield and material properties of nanocellulose derived from the Australian desert grass Triodia

Triodia, an endemic Australian grass genus of ∼70 species inhabiting arid and monsoonal regions, is an abundant and underused biomass resource. Harsh environmental conditions have driven the evolution of adaptive extremophile traits, including uniquely high aspect ratio cellulose nanofibres (CNFs) and high hemicellulose content. In this study, we advance understanding of CNFs by comparing three Triodia species (four ecotypes) grown in their natural desert habitat or cultivated in an irrigated farm setting. We evaluated biomass production, morphological and biochemical responses to these contrasting growth environments, and analysed the properties of fabricated nanopaper to assess the impact of species and growth environment on the material properties. We hypothesised that growing Triodia plants in well-watered and fertilised cultivation would relax arid environmental cues and may result in less desirable material properties. Contrary to our hypothesis, nanopaper derived from cultivated plants showed no regression in material properties compared to plants grown in their natural habitat. For instance, we found: (1) cultivated ‘soft’ species had a daily yield of greater than 2 g of dry biomass per plant; (2) three of the four ecotypes tested had higher hemicellulose contents in cultivation; (3) and with this higher hemicellulose content, the biomass proved to be more amenable to fibrillation, as cultivated plants achieved a lower average fibre diameter product. Overall, this study adds to the existing knowledge on the material properties of the Australian desert grass Triodia and the potential for production in agronomic settings. Understanding and potentially manipulating the traits of Australian desert grasses for beneficial material properties will accelerate the development of bio-based products in the future.

Nanocellulose toward Advanced Energy Storage Devices: Structure and Electrochemistry.

Cellulose is the most abundant biopolymer on Earth and has long been used as a sustainable building block of conventional paper. Note that nanocellulose accounts for nearly 40% of wood's weight and can be extracted using well-developed methods. Due to its appealing mechanical and electrochemical properties, including high specific modulus (∼100 GPa/(g/cm3)), excellent stability in most solvents, and stability over a wide electrochemical window, nanocellulose has been widely used as a separator, electrolyte, binder, and substrate material for energy storage. Additionally, nanocellulose-derived carbon materials have also drawn increasing scientific interest in sustainable energy storage due to their low-cost and raw-material abundance, high conductivity, and rational electrochemical performance. The inexpensive and environmentally friendly nature of nanocellulose and its derivatives as well as simple fabrication techniques make nanocellulose-based energy storage devices promising candidates for the future of "green" and renewable electronics. For nanocellulose-based energy storage, structure engineering and design play a vital role in achieving desired electrochemical properties and performances. Thus, it is important to identify suitable structure and design engineering strategies and to better understand their relationship. In this Account, we review recent developments in nanocellulose-based energy storage. Due to the limited space, we will mainly focus on structure design and engineering strategies in macrofiber, paper, and three-dimensional (3D) structured electrochemical energy storage (EES) devices and highlight progress made in our group. We first present the structure and properties of nanocellulose, with a particular discussion of nanocellulose from wood materials. We then go on to discuss studies on nanocellulose-based macrofiber, paper, and 3D wood- and other aerogel-based EES devices. Within this discussion, we highlight the use of natural nanocellulose as a flexible substrate for a macrofiber supercapacitor and an excellent electrolyte reservoir for a breathable textile lithium-oxygen battery. Paper batteries and supercapacitors using nanocellulose as a green dispersant, nanocellulose-based paper as a flexible substrate, and nanocellulose as separator and electrolyte are also examined. We highlight recent progress on wood-based batteries and supercapacitors, focusing on the advantages of wood materials for energy storage, the structure design and engineering strategies, and their microstructure and electrochemical properties. We discuss the influence of structure (particularly pores) on the electrochemical performance of the energy storage devices. By taking advantage of the straight, nature-made channels in wood materials, ultrathick, highly loaded, and low-tortuosity energy storage devices are demonstrated. Finally, we offer concluding remarks on the challenges and directions of future research in the field of nanocellulose-based energy storage devices.

Nanocellulose: Recent advances and its prospects in environmental remediation.

Among many other sustainable functional nanomaterials, nanocellulose is drawing increasing interest for use in environmental remediation technologies due to its numerous unique properties and functionalities. Nanocellulose is usually derived from the disintegration of naturally occurring polymers or produced by the action of bacteria. In this review, some invigorating perspectives on the challenges, future direction, and updates on the most relevant uses of nanocellulose in environmental remediation are discussed. The reported applications and properties of nanocellulose as an adsorbent, photocatalyst, flocculant, and membrane are reviewed in particular. However, additional effort will be required to implement and commercialize nanocellulose as a viable nanomaterial for remediation technologies. In this regard, the main challenges and limitations in working with nanocellulose-based materials are identified in an effort to improve the development and efficient use of nanocellulose in environmental remediation.

Treatment of Nanocellulose by Submerged Liquid Plasma for Surface Functionalization.

Tailoring the surface properties of nanocellulose to improve the compatibility of components in polymer nanocomposites is of great interest. In this work, dispersions of nanocellulose in water and acetonitrile were functionalized by submerged plasmas, with the aim of increasing the quality of this reinforcing agent in biopolymer composite materials. Both the morphology and surface chemistry of nanocellulose were influenced by the application of a plasma torch and filamentary jet plasma in a liquid suspension of nanocellulose. Depending on the type of plasma source and gas mixture the surface chemistry was modified by the incorporation of oxygen and nitrogen containing functional groups. The treatment conditions which lead to nanocellulose based polymer nanocomposites with superior mechanical properties were identified. This work provides a new eco-friendly method for the surface functionalization of nanocellulose directly in water suspension, thus overcoming the disadvantages of chemical treatments.

Recent Advances in Nanocellulose Composites with Polymers: A Guide for Choosing Partners and How to Incorporate Them.

In recent years, the research on nanocellulose composites with polymers has made significant contributions to the development of functional and sustainable materials. This review outlines the chemistry of the interaction between the nanocellulose and the polymer matrix, along with the extent of the reinforcement in their nanocomposites. In order to fabricate well-defined nanocomposites, the type of nanomaterial and the selection of the polymer matrix are always crucial from the viewpoint of polymer–filler compatibility for the desired reinforcement and specific application. In this review, recent articles on polymer/nanocellulose composites were taken into account to provide a clear understanding on how to use the surface functionalities of nanocellulose and to choose the polymer matrix in order to produce the nanocomposite. Here, we considered cellulose nanocrystal (CNC) and cellulose nanofiber (CNF) as the nanocellulosic materials. A brief discussion on their synthesis and properties was also incorporated. This review, overall, is a guide to help in designing polymer/nanocellulose composites through the utilization of nanocellulose properties and the selection of functional polymers, paving the way to specific polymer–filler interaction.

Nanocellulose films with combined cellulose nanofibers and nanocrystals: tailored thermal, optical and mechanical properties

Cellulose nanofibers (CNFs) and nanocrystals (CNCs) were prepared, and used to prepare thin CNF/CNC films. Rheological behavior of CNF/CNC suspensions and the other relevant properties of the films were characterized in comparison with a commercial porous polymer battery separator (PBS) film of similar thickness. The use of mixed CNFs and CNCs in the film-forming suspension led to significant variation of film morphology, and structural properties. With the addition of CNCs in hybrid nanocellulose material, the CNF/CNC suspension viscosity and zeta potential, film tensile strength, crystallinity index, and optical transparency were increased. With the increased CNF loading in the suspension, film porosity, thermal stability, and thermal expansion were enhanced. The CNF/CNC films exhibited better thermal stability, thermal expansion behavior, and optical properties than those of the commercial PBS film. The coefficient thermal expansion of the CNF/CNC and PBS films were 11.86–17.65 and 178.90 ppm/k, respectively. The CNF/CNC films had more uniform strength along all directions, whereas PBS film demonstrated anisotropic property. This work paves a new strategy to tailor the properties of nanocellulose based films.