Nanocellulose Solution Research Articles

Lithium Chloride-Mediated enhancement of dye removal capacity in Borneo bamboo derived nanocellulose-based nanocomposite membranes (NCMs)

Demand for sustainable materials for membrane fabrication is rapidly increasing, particularly in Sarawak coastal areas. nanocellulose emerges as a promising alternative for membrane development due to its availability, intrinsic biodegradability, and high strength. However, the hydrophobicity of nanocellulose limits its applicability in water treatment operations. Hence necessitating the need for innovative solutions. Herein, we examine the potential of bamboo-derived nanocellulose to enhance nanocomposite membrane-based water treatment systems by incorporating lithium chloride as a pore-forming additive. Nanocomposite membranes (NCMs) were synthesised using a LiCl-doped solution of nanocellulose and polyvinylidene fluoride (PVDF) through phase inversion and controlled solidification methods. The results show that nanocellulose incorporation induces structural alterations in NCMs, with reduced size in cellulose microfibrils. The crystallinity of nanocellulose was enhanced through interactions between PVDF and nanocellulose. The integration of nanocellulose along with lithium chloride was observed to have a significant impact on water permeation flux, attaining 104 L/m2h due to improved hydrophobicity and reduced fouling. In addition, the developed NCMs recorded 93 % methylene blue (MB) removal within 10 min. Revealing high potential of NCMs as an alternative and sustainable material for the development of nanocomposite membranes to mitigate contemporary challenges of water scarcity.

Novel antimicrobial polysaccharide hydrogel with fertilizer slow-release function for promoting Sesamum indicum L. seeds germination

The problem of seed germination is one of the important scientific and technological issues facing the field of agroforestry cultivation, and the germination process requires both sufficient water and certain nutrients. The high solubility of fertilizers and pesticides makes their utilization inefficient, while water resources are costly in difficult standing environments. This article innovatively provides the preparation of hydrogels with slow-release function by using cellulose and chitosan as substrates, which have high water retention capacity and long-lasting fertilizer release (CCH/PVA/NCC/NPK). In this study, cellulose chitosan hydrogel (CCH) with 50 wt% of chitosan, 1 wt% of polyvinyl alcohol solution (PVA), 0.5 wt% of nanocellulose solution (NCC), and 2.5 wt% of nitrogen, phosphorus, and potassium (NPK) solution were used in optimized conditions to successfully prepare hydrogel materials with swelling as high as 79 g g−1 of CCH/PVA/NCC/NPK. Under neutral conditions, CCH/PVA/NCC/NPK has the slowest water release rate and the strongest water retention capacity, and it can greatly reduce the amount of fertilizers and the consumption of water resources, and it has a wide range of applications and prospects for development.

Synthesis and Characterization of Nanocellulose/Polyacrylonitrile‐based Carbon Nanofibers: An Approach toward Low Cost and Sustainable Agro Waste based Carbon Nanomaterials

AbstractThe cost of polymer precursors and high energy need in carbonization for the preparation of carbon materials are two limiting factors in the commercialization of carbon‐based materials. In this study, carbon nanofiber films were prepared by adding a very small concentration of polymer polyacrylonitrile in nanocellulose (extracted from agro waste i.e., rice straws) with an overall aim of producing carbon nanomaterials with cost effective, renewable and sustainable carbon source. Polyacrylonitrile (PAN) added nanocellulose solution was drop‐casted to prepare Nanocellulose/Polyacrylonitrile‐based nanofibers film (NC/PAN). It was further stabilized in air atmosphere at 280 °C followed by carbonized in nitrogen atmosphere at 700 °C. It was found that addition of NC/PAN have 18 % lower activation energies than PAN. Results of tunneling electron microscopy showed that polyacrylonitrile/nanocellulose films carbonized at 700 °C temperature exhibited amorphous carbon nanofibers structure similar to bare polyacrylonitrile based carbon film carbonized at higher temperature of 1000 °C‐1200 °C. Furthermore, polyacrylonitrile/nanocellulose based carbon nanofibers have showed high degree of carbonization ((ID)/(IG)=0.87) as compared to bare polyacrylonitrile based carbon nanofibers film ((ID)/(IG)=1.02). This may be attributed to chiral nature of nanocellulose which served as a template to orientation of graphene planes and showed efficient carbonization.

Nanoparticles and magnetic field as novel elicitors improve seed germination and early growth of Mediterranean cypress

Abstract This study aimed to investigate the possibility of increasing the germination traits and early growth characteristics of Mediterranean cypress by applying nanopriming and magnetic field. To perform nanopriming, seeds were primed with nanochitin, nanochitosan and nanocellulose at a concentration of 1% for 2 h. For magnetopriming, the seeds were exposed to a magnetic field at three levels (20, 30 and 40 mT) for 1, 10 and 20 min and then sown. In combined treatment, the seeds were exposed to the magnetic field and then primed in nanoparticle solutions at the same treatments as mentioned earlier, and were planted. Non-exposed seeds were used as a control. The selected seed germination parameters (the percentage and speed of germination, stem and radicle length, collar root diameter, fresh and dry weights of the radicle and stem, number of leaves and leaf area) of young seedlings were examined. The interaction of nano × magnetic resulted in significant differences in the number of leaves, leaf area, length of the radicle, length of the stem, fresh weight of the radicle, fresh weight of the stem and stem dry weight traits. The results showed that among all the applied treatments, 10 min magnetism to 20 mT and then priming with 1% solution of nanocellulose was the best. It increased the germination percentage (1.31 times), germination rate (1.46 times), number of leaves (1.57 times), leaf area (1.36 times) and radicle length (1.74 times) compared to the control (no treatment). A 20-min treatment under a 30-mT magnetic field (without nanoprime) is also recommended.

Sustained antibacterial activity of orthodontic elastomeric ligature ties coated with a novel kombucha-derived bacterial nanocellulose: An in-vitro study.

Incipient carious lesions, the most common complication in orthodontic patients with fixed appliances, call for the development of novel preventive dental materials that do not rely on patient adherence. The present study aimed to assess the ability of elastomeric ligatures coated with bacterial nanocellulose (BNC) to deliver sustained antibacterial activity, during the standard 28-day interval between orthodontic appointments, without compromising their mechanical properties. Kombucha membrane was used to produce cellulose as a secondary product from the fermentation of tea broth with symbiotic bacteria and yeast culture. Characterization of BNC-coated elastomeric ligatures was performed using Fourier Transform Infrared Spectroscopy and Energy Dispersive Spectroscopy analysis. The samples were pre-treated by immersion first in isopropyl alcohol, then in 8 mL nanocellulose solution for 7 days. Tensile strain and strength of the BNC-coated and conventional ligatures were evaluated using a tensile testing machine. Direct contact and agar diffusion tests were performed to assess the antibacterial activity of nanocellulose. In addition, the release profile of BNC was evaluated. Data analysis was performed by one-way analysis of variance (ANOVA) followed by post-hoc Tukey's test and Wilcoxon signed-rank test. P values less than 0.05 was regarded as significant. There was no statistically significant difference in tensile strain and strength between the BNC-coated and conventional ligatures. The coated ligatures provided sustained antibacterial activity during the required 28 days. The use of BNC-coated elastomeric ligatures in patients with fixed orthodontic appliances might be a promising solution to plaque formation and subsequent enamel decalcification.

Synthesis and Characterization of Biocomposite Films of Methylcellulose-Based with Nanocellulose

This study explores the development of nontoxic biocomposite films from methylcellulose (MC) and crystalline nanocellulose (CNC). First, a methylcellulose sample (Tylose MH 50) of concentration 1.5% (w/w) and crystalline nanocellulose type-1 samples of different concentrations were prepared to obtain these biocomposite films. Films were then produced by adjusting methylcellulose solution with nanocellulose solution following the casting-evaporation methodology. The molecular interactions of crystalline nanocellulose with methylcellulose were investigated using ATR Fourier Transform Infrared (FTIR) spectroscopy. FTIR analysis of films revealed a shift of absorption peak in the region of 3200-3600 cm-1 to a lower value and found an intense peak at 1031 cm-1 with the incorporation of CNC into Tylose MH 50 film. The thermal stability of these films was examined using thermogravimetric analysis (TGA), indicating the films' higher stability than MC. Mechanical properties were measured by controlled RH by dynamic mechanical analysis (DMA), showing changes in Young's modulus from the initial slope of stress-strain plots and storage modulus (E′) as the concentration of CNC increased in films. The data were obtained from bionanocomposite films, which were not even with variations in thickness as measured by a digital micrometer. The mechanical properties of bionanocomposite films showed variation due to the varying local orientation of CNCs in MC, as it contradicts work that was previously done in this area which suggests a uniform orientation of CNCs in MC biopolymer. Further research on these biocomposite films is expected to find more significant uses.

Remediation of Pear Iron Deficiency Chlorosis by Nanocellulose-iron Chelation and the Underlying Mechanism

Nanocrystal cellulose possesses a strong capability to chelate Fe due to its adsorptive properties. Iron deficiency chlorosis (IDC) is a mineral disorder that remarkably weakens pear photosynthesis, causing declines in plant yields and quality. Conventional methods for controlling IDC generally lack efficiency and overuse chemicals. Foliar application of nanocellulose (NC)-Fe chelate (NCFe) provides a new approach to remediate IDC in pear (Pyrus betulifolia). In this study, NC was prepared by acidic hydrolysis using 64 wt% H2SO4 at 45 °C for 45 minutes. NCFe was formulated based on the net charge density of NC and ferrous sulfate (FeSO4) solution. The nanoparticle properties were characterized by transmission electron microscopy (TEM), dynamic light scattering, and conductometry. Pyrus betulifolia seedlings were pre-etiolated in an improved Hoagland’s nutrient solution and treated with bicarbonate. Changes in chlorophyll content, active Fe content, and photosynthesis rate in NCFe-treated leaves were determined by SPAD values, spectrophotometry, and photosynthetic apparatus, respectively. Ferritin genes (PbFER) and pectin methylesterase genes (PbPME) were extracted from leaf tissue, and gene expression profiles were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). The results showed that NCFe particles maintained a whisker-like morphology; the Z-average hydrodynamic diameter and zeta potential of NCFe measured by dynamic light scattering were 107.4 ± 3.0 nm and −9.7 ± 0.4 mV, respectively. When NCFe was prepared at a mixing ratio of 1:3000, the total chlorophyll content, active Fe content, and net photosynthetic rate of plant leaves were significantly enhanced by 23.8%, 65.9%, and 40.4% after 72 hours of treatment, respectively, compared with FeSO4 spraying. Importantly, NCFe treatment also significantly downregulated the expression of PbPME and upregulated the expression of PbFER, which are key genes regulating the active Fe content.

Investigation of Swelling Ratio and Textures Analysis of Acrylamide-Nanocellulose Corncobs Hydrogel

Corncobs have a high level of cellulose hence making it suitable to be used as the main ingredient in making hydrogels. Hydrogel are crosslinked polymers capable of absorbing water hundreds to thousands of times their dry weight, but are insoluble in water due to the three-dimensional structure of the polymer network. Hydrogel can be synthesized using corncobs cellulose and acrylate-acrylamide with chemical crosslinking methods. This study aims to determine the effect of adding corncobs cellulose and acrylate-acrylamide on hydrogel ability to swelling ratio, gel fraction and texture analysis. Nanohydrogel were synthesized by cellulose concentration by 5-25% while acrylamide was varied 10,12 and 16 %. The treatment concentration ratio of nanocellulose solution to acrylamide also showed a significantly different effect at 5% level. The optimum hydrogel synthesis was the treatment of 10 % cellulose ratio and 16% acrylamide ratio which has a swelling ability of 15152.3% (g/g) and gel fraction 56.6%. The increasing the concentration of cellulose caused the hardness value to be higher but the springiness value tends to decrease. Morphology analysis showed the surface of hydrogels that are porous, has lumps and forms a three-dimensional tissue.

Development of Active Barrier Multilayer Films Based on Electrospun Antimicrobial Hot-Tack Food Waste Derived Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and Cellulose Nanocrystal Interlayers.

Active multilayer films based on polyhydroxyalkanoates (PHAs) with and without high barrier coatings of cellulose nanocrystals (CNCs) were herein successfully developed. To this end, an electrospun antimicrobial hot-tack layer made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) derived from cheese whey, a by-product from the dairy industry, was deposited on a previously manufactured blown film of commercial food contact PHA-based resin. A hybrid combination of oregano essential oil (OEO) and zinc oxide nanoparticles (ZnONPs) were incorporated during the electrospinning process into the PHBV nanofibers at 2.5 and 2.25 wt%, respectively, in order to provide antimicrobial properties. A barrier CNC coating was also applied by casting from an aqueous solution of nanocellulose at 2 wt% using a rod at 1m/min. The whole multilayer structure was thereafter assembled in a pilot roll-to-roll laminating system, where the blown PHA-based film was located as the outer layers while the electrospun antimicrobial hot-tack PHBV layer and the barrier CNC coating were placed as interlayers. The resultant multilayer films, having a final thickness in the 130–150 µm range, were characterized to ascertain their potential in biodegradable food packaging. The multilayers showed contact transparency, interlayer adhesion, improved barrier to water and limonene vapors, and intermediate mechanical performance. Moreover, the films presented high antimicrobial and antioxidant activities in both open and closed systems for up to 15 days. Finally, the food safety of the multilayers was assessed by migration and cytotoxicity tests, demonstrating that the films are safe to use in both alcoholic and acid food simulants and they are also not cytotoxic for Caco-2 cells.

Cellulose nanocrystals/silver nanoparticles: in-situ preparation and application in PVA films

Abstract With the increasing application of polyvinyl alcohol (PVA) films in the field of food packaging, it is important to improve its mechanical and antibacterial properties. This paper focuses on the preparation of PVA nanocomposite films and how their properties are affected by a silver-loaded nanocellulose solution. Cellulose nanocrystals (CNCs) were used as both the carrier and the dispersant of silver nanoparticles (AgNPs) prepared using glucose as the reducing agent. Ag+ was stabilized by the many hydroxyl groups located in the CNCs, and then the Ag+ was reduced to AgNPs in situ. After addition of silver-loaded nanocellulose, the tensile strength of the CNC-PVA-AgNP films increased from 47 MPa to 73 MPa, and the nanocomposite films displayed reduced moisture absorption and good antibacterial properties.

Cellulose-based nano hydrogel from corncob by gamma irradiation

Based on economic nomenclature of Indonesian food crops, corn is the second important commodity after rice. The high corn production correlates with corncob waste produced. The existence of corncob waste is abundant and continuous post-harvest. One alternative to utilize of corncob waste is the high content of cellulose processed to cellulose-based nano hydrogel. In this study, cellulose from corncob was processed into hydrogel by gamma irradiation. Cellulose size reduction is done by the wet milling process. The treatment tested of nano hydrogel control was cellulose dissolved in NaOH/PEG solvent whereas the ratio of cellulose: solvent was 1:2 and 1:4 and nano hydrogel by gamma irradiation that nano-cellulose solution was filtered by vacuum filtration. The aim of this research was to find out the characteristics of nano hydrogel by gamma irradiation. Parameters observed were swelling ratio, gel fraction, texture and morphology. The result showed that the treatment test of nano hydrogel without gamma radiation has 111% and 127% swelling ratio, meanwhile, nano hydrogel with gamma irradiation has a 214% swelling ratio, 99% gel fraction and 1.17 mJ hardness with morphology showed higher porosity. The higher swelling ratio of nano hydrogel by gamma irradiation has the potential for application in agriculture as water absorbent material and fertilizer carrier agent.

The use of nanocellulose in the production of medium density particleboard panels and the modification of its physical properties

Wood-based panel applications recently have expanded and become increasingly competitive, especially within the furniture and civil construction industries. To remain competitive, such products must present physical properties that meet consumer needs. In this context, the incorporation of nanomaterials is gaining momentum, mainly as a means to improve the physical characteristics of panels, thereby expanding their applications. The aim of this study was to evaluate the physical properties of medium density particleboard (MDP) panels after adding various proportions of nanocellulose in place of water to the urea-formaldehyde (UF) adhesive in MDP panel production. The results showed that the addition of nanocellulose resulted in no significant statistical difference in the density and moisture content of the panels. When tested for thickness swelling, only the panel with 100% nanocellulose solution exhibited a significantly higher value. The panels were subjected to scanning electron microscopy (SEM) analysis, which showed that the addition of nanocellulose led to a more polished, less irregular surface. Such physical effects of nanocellulose can potentially make panels more suitable for coating applications. The feasibility of coatings on nanocellulose MDP panels can be verified through future tests to determine the surface roughness of the panels.

Butanol-mediated oven-drying of nanocellulose with enhanced dehydration rate and aqueous re-dispersion

The application potential of nanocellulose has been previously hindered by the costly and slow drying methods that this material requires, including freeze/supercritical drying process. The main issue for nanocellulose commercialization is how effectively and rapidly its high water contents (90–99%) can be removed, all of which raise its transportation and processing costs. Oven-drying is the fastest, most economical, and most scalable method for dehydrating nanocellulose, but causes strong interfibrillar aggregation and leads to poor aqueous re-dispersion. Here, we report that the problems of nanocellulose oven-drying are comprehensively overcome by adding tert-butanol (t-BuOH) to the nanocellulose solution at >90%. In a lab-scale comparison, the t-BuOH-mediated oven-drying of aqueous nanocellulose showed lower drying times by a factor of 2–12 compared to water only oven-drying and freeze drying of the same material. The dispersibility of this dried nanocellulose is as high as the never-dried material in terms of particle size, light transmittance, and sedimentation. t-BuOH reduces interfibrillar shrinkage due to the lower surface tension of t-BuOH compared to water, and a remaining t-BuOH/water mixture decreases interfibrillar adhesion and contact.

Catalytic Reductions and Tandem Reactions of Nitro Compounds Using in Situ Prepared Nickel Boride Catalyst in Nanocellulose Solution.

A mild and efficient method for the in situ reduction of a wide range of nitroarenes and aliphatic nitrocompounds to amines in excellent yields using nickel chloride/sodium borohydride in a solution of TEMPO-oxidized nanocellulose in water (0.01 wt %) is described. The nanocellulose has a stabilizing effect on the catalyst, which increases the turnover number and enables low loading of nickel catalyst (0.1-0.25 mol % NiCl2). In addition, two tandem protocols were developed in which the in situ formed amines were either Boc-protected to carbamates or further reacted with an epoxide to yield β-amino alcohols in excellent yields.

Chitosan–bacterial nanocellulose nanofibrous structures for potential wound dressing applications

The fabrication of nonwoven mats containing chitosan and bacterial nanocellulose by electrospinning were considered using two different approaches: (1) simultaneous spinning of chitosan and bacterial nanocellulose solutions using two separate syringes towards the same target and (2) coaxial electrospinning, where chitosan and bacterial nanocellulose were simultaneously electrospun through a spinneret composed of two concentric needles to produce core–shell structures. Co-spinning agents were required in both approaches. A direct blend of chitosan and bacterial nanocellulose and subsequent electrospinning was not feasible due to the incompatibility of their respective solvents. The first approach led to the production of mats containing both chitosan and bacterial nanocellulose nanofibers. However, few bacterial nanocellulose fibers were deposited on the collector. Addition of polylactide as a co-spinning agent and an increase in solution temperature (from 22 to 60 °C) during electrospinning was required to improve both fiber formation and collection. On the other hand, coaxial electrospinning showed the best results for the production of nanofibers containing both chitosan and bacterial nanocellulose. Nanofibers with a good yield were obtained by using a chitosan/poly(ethylene oxide) (2.4/0.6 wt/v%) aqueous solution as the inner layer, and a bacterial nanocellulose solution (0.6 wt/v%) as the outer layer. Co-electrospun nanofibers had a diameter of 85 nm in average, and a narrow size distribution. The core/shell nanostructure was validated by transmission electron microscopy whilst energy-dispersive X-ray spectroscopy analysis showed that the nanofibers contained both chitosan and bacterial nanocellulose along their structure. Finally, the mats obtained by the coaxial approach exhibited strong antimicrobial activity with a decrease of 99.9 % of an Escherichia coli population.

THE POTENTIAL OF OPTICAL TWEEZER (OT) FOR VISCOELASTIVITY MEASUREMENT OF NANOCELLULOSE SOLUTION

In this paper, we review the recent applications of optical tweezer (OT) in studying the microrheology of variety of polymeric solution. Our aim is to expose optical tweezer research to the public and newcomer. This paper highlights and summarizes the advantages of optical tweezer as compared with the conventional method, introduces the benefit of nanocellulose and also presents an overview of the potential in the measurement of nanocellulose solution’s viscoelasticity by using optical trapping method.