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•A sensitive and selective impedimetric detection of cadmium ions was achieved.•Disposable screen printed electrodes were modified with a nanocomposite (Nanocellulose/ ligand / ...nanocomposite (CNT/Co3O4)).•Nanocellulose integrated nanomaterial improved the assay selectivity and electrochemical responses.
In this work, a new class of heterocyclic-ligands/Nanocellulose/Co3O4/carbon-nanotube-nanocomposite was synthesized, characterized, and implemented as a new sensor platform for the ultra-trace impedimetric direct detection of cadmium ions in tap water samples. A simple synthesis approach was used for producing cellulosic nanostructures that were integrated with several heterocyclic ligands (L/Nanocellulose) to be exploited as the sensor platform. For acquiring high electrocatalytic combined with fast electrochemical responses, metal oxides/carbon nanotubes were integrated with one of the selected L/Nanocellulose to eventually form CNT/Co3O4/L/cellulose nanocomposite. The impedimetric method was optimized to reach sub-picomolar sensitivity with no cross-reactivity with other metal ions. From the calibration curve, high sensitivity and a wide linear range was achieved over the concentrations (10-13 M to10-2 M), with lower of detection limit (LOD) of 1.5 × 10-13 M (S/N = 7), R2 of 0.99. The sensor was applied for real sample (tap-water) analysis, while a high recovery percentage (96–120 %) was attained.
Objective: The main objective of this work was to understand the basic properties of crystalline nanocellulose (CNC) that can be useful as a novel excipient in pharmaceutical formulations. This ...covers the isolation and preparation of nanocellulose followed by characterization.
Methods: Cellulose was isolated from aquatic weed by autoclaving and bleaching. Cellulose to CNC conversion involved gluconic acid treatments at different concentrations (40%, 50% and 60%) followed by centrifugation and neutralization. CNC was further characterized by Differential Scanning Calorimetry (DSC) and Thermo gravimetric Analysis (TGA), Field Emission Scanning Electron Microscopy (FE-SEM) and Atomic Force Microscopy (AFM) for surface morphology, elemental analysis by Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), crystallinity index by X-Ray Diffraction (XRD), and optical microscopy.
Results: Acid concentration affects the moisture uptake, particle size, and yield of CNC. CNC size ranged from 350 nm to 900 nm with a crystallinity index 80% to 85%. Moisture uptake was 6.38±0.12% at 33% relative humidity. DSC and TGA established thermal stability over 200 °C. Nanocellulose has shown Angle of repose (28.81°), Carrs index (12.32), zeta potential (33mV) values and heavy metals within pharmacopoeial limits.
Conclusion: CNC from water hyacinth was prepared successfully by sustainable process. CNC physico-chemical characterization revealed the stable nature of CNC, suitable to be used as an excipient in pharmaceutical formulations.
The high demand for plastic and polymeric materials which keeps rising every year makes them important industries, for which sustainability is a crucial aspect to be taken into account. Therefore, it ...becomes a requirement to makes it a clean and eco-friendly industry. Cellulose creates an excellent opportunity to minimize the effect of non-degradable materials by using it as a filler for either a synthesis matrix or a natural starch matrix. It is the primary substance in the walls of plant cells, helping plants to remain stiff and upright, and can be found in plant sources, agriculture waste, animals, and bacterial pellicle. In this review, we discussed the recent research development and studies in the field of biocomposites that focused on the techniques of extracting micro- and nanocellulose, treatment and modification of cellulose, classification, and applications of cellulose. In addition, this review paper looked inward on how the reinforcement of micro- and nanocellulose can yield a material with improved performance. This article featured the performances, limitations, and possible areas of improvement to fit into the broader range of engineering applications.
Nanocellulose is often being regarded as the next generation renewable reinforcement for the production of high performance biocomposites. This feature article reviews the various nanocellulose ...reinforced polymer composites reported in literature and discusses the potential of nanocellulose as reinforcement for the production of renewable high performance polymer nanocomposites. The theoretical and experimentally determined tensile properties of nanocellulose are also reviewed. In addition to this, the reinforcing ability of BC and NFC is juxtaposed. In order to analyse the various cellulose-reinforced polymer nanocomposites reported in literature, Cox–Krenchel and rule-of-mixture models have been used to elucidate the potential of nanocellulose in composite applications. There may be potential for improvement since the tensile modulus and strength of most cellulose nanocomposites reported in literature scale linearly with the tensile modulus and strength of the cellulose nanopaper structures. Better dispersion of individual cellulose nanofibres in the polymer matrix may improve composite properties.
Nanocellulose has been adopted to fabricate renewable and thermally stable separators for lithium ion batteries (LIBs). However, the nanofibrils tend to form dense network because of the capillarity ...during drying, consequently limiting the electrolyte retention capability of the membrane and blocking the migration of ions. To tackle the problems, a novel method is presented to fabricate a nanocellulose based separator with high porosity and multiscale pore structure. The micro-sized pores derived from the dissolution of PS spheres can assure a highly porous feature of the separator. The nano-sized pores fabricated from the ethanol bath further increase the porosity and improve the permeability of the separator. Although the resultant pores weaken the mechanical strength of the separator, the electrochemical performances including the ionic conductivity, interfacial resistance and electrochemical window are ameliorated due to the distinctive microstructures. Moreover, the battery performances, containing capacity retention and rate capability, of the coin battery assembled with the as-constructed separator are proven to be agreeable by the battery test.
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•A nanocellulose separator with a multiscale pore structure was prepared.•The ethanol bath was introduced to fabricate nano-sized pores.•The polystyrene spheres were used to produce micro-sized pores.•The as-designed separator could achieve a potential application for LIBs.
A nanocomposite from a green nanomaterial (nanocellulose) and f-MWCNTs was modified onto glassy carbon (GC) electrode for the detection of diclofenac sodium (DCF), a non-steroidal anti-inflammatory ...drug (NSAID) and widely used electroactive painkiller. The presence of OH groups in the nanocellulose provides more binding sites for different analytes. This ensures an axial modulus rearrangement and the incorporation of f-MWCNTs which provides larger surface area, high mechanical strength and improved electrical conductivity. On the other hand, the synergy between both compounds enhances the electrochemical detection of DCF in human blood and urine. Under optimum conditions, the modified electrode exhibited a remarkable improvement in the anodic peak current (41.6 μA) for 50 μM DCF at 0.677 V peak potential. The newly fabricated electrode showed two linear dynamic ranges from 0.05 to 1.00 μM and 2–250 μM DCF with low detection limit of 0.012 μM. In addition, differential pulse voltammetry (DPV) and cyclic voltammetry (CV) showed good sensitivity and selectivity for the determination of DCF. With this technique, the modified electrode was very effective and suitable for DCF determination from commercial tablets, ampoules (pharmaceutical preparations) and also from clinical preparations (human blood serum and urine sample) with good recoveries.
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•A non-enzymatic sensor has been developed for the detection of diclofenac sodium.•The sensor was fabricated by using novel and green nanomaterials based hybrid nano composite (nanocellulose/f-MWCNTs).•This fabricated sensor has low detection limit, dynamic range, good reproducibility, stability and sensitivity.•Successful determination of diclofenac sodium in pharmaceutical dosage, human blood serum and urine.
Nanocellulose is a renewable and biocompatible nanomaterial that evokes much interest because of its versatility in various applications. This study reports the production of nanocellulose from Agave ...gigantea (AG) fiber using the chemical-ultrafine grinding treatment. Chemical treatment (alkalization and bleaching) removed non-cellulose components (hemicellulose and lignin), while ultrafine grinding reduced the size of cellulose microfibrils into nanocellulose. From the observation of Transmission Electron Microscopy, the average diameter of nanocellulose was 4.07 nm. The effect of chemical-ultrafine grinding on the morphology and properties of AG fiber was identified using chemical composition, Scanning Electron Microscopy, X-ray Diffraction, Fourier Transform Infrared, and Thermogravimetric Analysis. The bleaching treatment increased the crystal index by 48.3% compared to raw AG fiber, along with an increase in the cellulose content of 20.4%. The ultrafine grinding process caused a decrease in the crystal content of the AG fiber. The crystal index affected the thermal stability of the AG fiber. The TGA results showed that AG fiber treated with bleaching showed the highest thermal stability compared to AG fiber without treatment. The FTIR analysis showed that the presence of CH vibrations from the ether in the fiber. After chemical treatment, the peaks at 1605 and 1243 cm−1 disappeared, indicating the loss of lignin and hemicellulose functional groups in AG fiber. As a result, nanocellulose derived from AG fiber can be applied as reinforcement in environmentally friendly polymer biocomposites.
•The increase in AG cellulose content after the chemical treatment•Mechanical treatment was successful in the production of nanocellulose with an average diameter of 4.07 nm•A crystallinity index (71%) was observed for bleached AG fibers compared to untreated fibers (49%)•The optimal chemical-mechanical treatment gave excellent properties of cellulose purity and cellulose nanofiber production
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•CNFs are not adsorbed onto methyl methacrylate oil with low interfacial tension.•CNFs can be adsorbed on oil droplets with an additional oil controlling wettability.•Nanocomposites ...from Pickering emulsions show nanodispersed CNFs in a polymer matrix.•Nanocomposites show high optical property, mechanical property and thermal stability.
Cellulose nanofibrils (CNFs) are promising candidates as a sustainable polymer reinforcement material, but incompatibility makes it difficult to be incorporated into a polymeric matrix. Pickering emulsion-templated synthesis, in which nanometer-sized polymeric particles covered with CNFs are formed, provides a useful route to disperse nano-sized fillers within incompatible polymers. However, CNF does not always adsorb to monomer droplets (e.g., methyl methacrylate), which is the most important step fabricating polymeric particles covered by CNFs. Here, by adding an appropriate oil to a monomer, we show that the adsorption of CNF on the oil can be dramatically enhanced by controlling the interfacial tension. Using this approach, poly (methyl methacrylate) (PMMA) nanocomposites reinforced with CNFs were fabricated. The PMMA nanocomposite films exhibit high optical properties and mechanical properties as well as thermal stability. The Pickering emulsion template with the additional oil approach can be applied to any emulsion-based polymerization methods for nanocomposite materials.
The utilization of nanocellulose has increasingly gained attentions from various research fields, especially the field of polymer nanocomposites owing to the growing environmental hazardous of ...petroleum based fiber products. Meanwhile, the searching of alternative cellulose sources from different plants has become the interests for producing nanocellulose with varying characterizations that expectedly suit in specific field of applications. In this content the long and strong bast fibers from plant species was gradually getting its remarkable position in the field of nanocellulose extraction and nanocomposites fabrications. This review article intended to present an overview of the chemical structure of cellulose, different types of nanocellulose, bast fibers compositions, structure, polylactic acid (PLA) and the most probable processing techniques on the developments of nanocellulose from different bast fibers especially jute, kenaf, hemp, flax, ramie and roselle and its nanocomposites. This article however more focused on the fabrication of PLA based nanocomposites due to its high firmness, biodegradability and sustainability properties in developed products towards the environment. Along with this it also explored a couple of issues to improve the processing techniques of bast fibers nanocellulose and its reinforcement in the PLA biopolymer as final products.
•Nanocellulose obtained from flax, hemp, jute and kenaf fibers.•Techniques of processing bast fibers into various nanocellulose product.•Current development of bast fiber nanocellulose for polylactic acid nanocomposites.•Fabrication methods of polylactic acid reinforced with bast fiber nanocellulose.•Potentiality of roselle, mulberry and ramie fibers for obtaining nanocellulose.
Nanocellulose films possess numerous merits ascribing to their inherent biocompatibility, non-toxic and biodegradability properties. The potential for practical applications would be improved if ...their mechanical strength and toughness requirements could be met simultaneously. Herein, dual cross-linked nanocellulose (DC) film was fabricated by the treatments of chemical and physical cross-linking, which was mechanically superior to pure nanocellulose (CNF) films. To further increase the toughness of DC films, spherical cellulose (Sph) was incorporated into DC film (DC-Sph film), and analyzed under different humidity conditions (RH) (from 10 % to 90 %). The changes of functional groups of CNF, DC and DC-Sph films were detected by FTIR and XPS spectrum. The epichlorohydrin and Sph content were optimized, followed by the investigation of RH on the toughness of films. The highest tensile strength (146.6 ± 4.6 MPa) was obtained in DC film at 50 % RH, while the DC-Sph film showed the largest toughness (40.3 ± 3.7 kJ/m2) at 70 % RH. Furthermore, the possible toughening mechanism of DC-Sph film was also discussed.
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