Isolation Of Nanocellulose Research Articles

Characterization of cellulosic samples obtained from sisal fibers

In this work the reaction conditions of different chemical treatments used for the isolation of nanocellulose were evaluated. This study clarified the effect of different reaction conditions (time or concentration) on the structure and composition of the cellulosic fibers, To achieve this objective, different chemical, thermal and morphological characterization techniques were used after each chemical treatment and the most suitable reaction conditions were selected.

The role of deep eutectic solvents in the production of cellulose nanomaterials from biomass

Abstract In recent years, the demand for environment-friendly products has been on an increasing trend among researchers and industry for sustainable development. Deep eutectic solvents are green solvents which, due to their properties (biodegradability, recyclability, low cost, availability, easy preparation, low toxicity, chemical and thermal stability), can be used in various fields such as polymer chemistry, which includes nanocellulose isolation and polysaccharides processing. Several studies have illustrated the effectiveness of using deep eutectic solvents instead of the conventional reaction system to produce and disperse nanomaterials. This work summarizes the use of deep eutectic solvents in the isolation of cellulosic nanomaterials from different types of biomass. Deep eutectic solvents demonstrate high effectiveness in swelling lignocellulosic biomass and producing cellulose nanomaterials. Overall, deep eutectics solvents represent an innovative and effective pretreatment process for the fractionation of raw cellulose-containing fibres to promote subsequent isolation of nanomaterials made from cellulose.

Isolation of Nanocellulose from Aquatic Wetland Plant-Eleocharis dulcis

Eleocharis dulcis is a sustainable wetland material available in enormous quantities in Kalimantan, Indonesia. This study aimed to evaluate the suitability of the acid hydrolysis method for the isolation of nanocellulose of E. dulcis. The isolation process started with delignification, followed by the removal of hemicellulose to produce cellulose. The hydrolysis was performed at 45 ºC for 60 and 120 min, respectively, using sulphuric acid. Furthermore the nanocellulose was characterized using particle size analyzer, Fourier transform infrared spectroscopy and X-ray diffractions. The particle size analysis showed that the diameter of the nanocellulose was affected by hydrolysis time. In addition, the X-ray diffractions results showed that the crystallinity index of the nanocellulose was 71.99% and 71.61% for the acid hydrolysis time of 60 min and 120 min, respectively. This study also demonstrated that the aquatic wetland plant, E. dulcis has a good potential for nanocellulose production in Indonesia.

Isolation of high crystalline nanocellulose from Mimosa pudica plant fibres with potential in packaging applications

AbstractMimosa pudica Linn (sensitive plant) is a medicinal plant of family Fabaceae. Its stem is a good source of cellulose. This research work reports isolation of cellulose nanocrystals (CNCs) from M. pudica stem fibres by combined chemical and mechanical treatments. Polyvinyl alcohol (PVA)/starch composites were prepared with incorporation of isolated CNC (1, 3 and 5 wt.%) by solution casting method. Addition of CNC in polymer composites improved its mechanical strength and barrier properties. Isolation process of CNC includes alkali treatment, bleaching and acid hydrolysis followed by homogenization. Chemical composition, thermal stability, structure, surface morphology, crystallinity and size of the freeze‐dried nanocellulose were studied carefully. Fourier transform infrared analysis of raw fibre and CNC showed elimination of non‐cellulosic fragments from untreated M. pudica stem fibre. Electron microscopy analysis and dynamic light scattering (DLS) confirmed the isolation of nanocellulose. X‐ray diffraction showed improvement in the crystallinity of obtained nanocellulose. Increase in crystallinity indicates high Young's modulus of isolated nanocellulose which makes them proper reinforcement material in composites. Polymer composites with the addition of 3 wt.% of CNC showed the highest tensile strength and lowest water vapour transmission rate (WVTR), moisture absorption and oxygen transmission rate (OTR). As M. pudica is an abundant natural resource, it can be utilized as an efficient source of nanocellulose for different applications especially as fillers in sustainable polymer composites for packaging.

Rapid, high-yield production of lignin-containing cellulose nanocrystals using recyclable oxalic acid dihydrate

Nanocellulose is of growing interest due to its great potential in many value-added applications and its unique characteristics. However, conventional methods for nanocellulose isolation are challenged by various economic and environmental concerns. With the use of recyclable oxalic acid dihydrate (OAD), this study demonstrated the rapid, high-yield production of lignin-containing cellulose nanocrystals (LCNCs) from thermomechanical pulp (TMP). Serving as the sole solvent and reactant, molten OAD effectively hydrolyzed TMP within 30 min at 110 °C, leading to complete removal of hemicellulose (97 %) but retaining most of the cellulose (93 %) and lignin (97 %). This modified TMP can be converted into LCNCs with a high overall yield of >70 % via microfluidization. The LCNCs possessed satisfactory thermal stability and exhibited a nanoscale morphology of highly uniform cellulose nanocrystals (7.0 nm in width, 3.9 nm in height, 200–300 nm in length, and 72 % in crystallinity), randomly implanted by lignin aggregates. The unreacted OAD could also be readily recycled via crystallization from the post-hydrolysis mixture. The recycled OAD showed good performance retention for at least 4 cycles, indicating its suitability for continuous TMP hydrolysis. Further life cycle assessment suggested that the recycling potential could reduce the global warming potential and energy use by 48 % and 47 %, respectively. Overall, it was apparent that recycling molten OAD provided a promising approach to rapidly make clean, high-yield LCNCs with low energy use and improved reagent utilization.

Production of Nanocellulose Crystal Derived from Enset Fiber Using Acid Hydrolysis Coupled with Ultrasonication, Isolation, Statistical Modeling, Optimization, and Characterizations

Currently, many scholars are looking for renewable biomass sources for the isolation of nanomaterials that have a sustainable property and are ecofriendly. Thus, effectively synthesize and characterization enset fiber nanocellulose using acid hydrolysis with sonication is focus of study. Additionally, process optimization for isolation of nanocellulose (CNCs) from raw enset fiber using RSM-CCD and characterizations of obtained CNCs was explored. The quadratic model was selected, and optimized values for CNCs yield (77.69%) that were acquired to be H2SO4: 51.6 wt. %, reaction temperature: 47°C, and time: 66.5 min. Chemical composition analysis, XRD, FTIR, PSA, SEM, and TGA were used for characterizing CNCs. The particle size distribution of CNCs is 66 nm. It has a crystalline index of 80.91% and excellent thermal stability. FTIR and chemical composition result indicated the reduction and removal of lignin and hemicellulose components that are usually available in the raw enset fibers. The SEM analysis reveals the structure and arrangement of the fiber bundles inside the raw material to nanocellulose. This property shows its endowing as a possibly consistent load-bearing material. This study could be given a noteworthy thought for designing and emerging CNC isolation, optimization, and industrial application.

Nanocellulose from Agricultural Wastes: Products and Applications—A Review

The isolation of nanocellulose from different agricultural residues is becoming an important research field due to its versatile applications. This work collects different production processes, including conditioning steps, pretreatments, bleaching processes and finally purification for the production of nanocellulose in its main types of morphologies: cellulose nanofiber (CNF) and cellulose nanocrystal (CNC). This review highlights the importance of agricultural wastes in the production of nanocellulose in order to reduce environmental impact, use of fossil resources, guarantee sustainable economic growth and close the circle of resource use. Finally, the possible applications of the nanocellulose obtained as a new source of raw material in various industrial fields are discussed.

Exploring the role of chemo-mechanical technique on the properties of nanocellulose isolated from different varieties of rice bran

Nanocellulose (NC) was isolated from an underutilized agricultural residue, defatted rice bran (DRB), obtained from three major paddy varieties in Malaysia, MARDI Rice (MR): MR 220, MR 219, and MR 297. The DRB was subjected to alkali (NaOH) and bleaching treatments prior to the isolation of NC. The NC from DRB was produced through the acid hydrolysis technique using 55%wt sulphuric acid (H2SO4) with the assistance of ultrasonication. The morphological structure of NC was analyzed through transmission electron microscopy (TEM). Based on the observation, a needle-like structure was observed for NC 219 while NC 220 and NC 297 showed nano-web structures. All obtained NC dimensions ranged from 183 to 263 nm long and 4.70 to 4.97 nm wide. Fourier transform infrared (FTIR) spectroscopy revealed the presence of all important compositions for the cellulose of each variety, indicating that the chemical structure of DRB cellulose has not been altered by acid hydrolysis. Particle size distributions portrayed a unimodal graph for NC 220 and NC 219. This comparative study provides an insight into the possibility of using DRB as a potential source of NC. The promising characteristics of NC from MR 219 allowed its application as an emulsifier for stabilizing a solid particle-based emulsion.

Cellulose and TiO2–ZrO2 Nanocomposite as a Catalyst for Glucose Conversion to 5-EMF

This work demonstrated the use of green material catalysts, produced from Sengon sawdust waste, to obtain nanocellulose biopolymers. The green material catalysts were utilized as catalysts support of TiO2−ZrO2 binary oxide in the form of nanocomposite materials with superior synergistic properties. The isolation of nanocellulose was achieved using a hydrolysis method with a yield of 63.40%. The TiO2 and ZrO2 nanoparticles have average particle sizes of around 25 and 15 nm, respectively, and the binary oxides of TiO2–ZrO2 pretained an average particle size of 30 nm were used. Furthermore, the nanocellulose combined with the TiO2−ZrO2 binary oxide had formed a cellulose/TiO2−ZrO2 nanocomposite with an average particle size of 30 nm. This indicates that the supporting nanocellulose can stabilize the nanoparticles and avoid aggregation. Moreover, the nanocomposites can be used as a catalyst for the conversion of glucose to 5-ethoxymethylfurfural (5-EMF). The catalytic activity increased with the nanoparticle effect obtained ZrO2, TiO2, TiO2-ZrO2, and cellulose and TiO2-ZrO2 nanocomposite, in 15.50%, 20.20%, 35.20%, and 45.50% yields, respectively. The best yield of 5-EMF was 45.50%, with reaction conditions of 1:1 TiO2–ZrO2 ratio, 4 h reaction time, and 160 °C reaction temperature. The use of nanocellulose biopolymer generated from Sengon sawdust waste in Indonesia provides a promising catalyst support material as an alternative green catalyst. In addition, the glucose carbohydrates can be converted to biofuel feedstocks in the development of a renewable alternative energy. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Isolation of lignin‐containing cellulose nanocrystals: life‐cycle environmental impacts and opportunities for improvement

AbstractDeep eutectic solvent (DES) has recently been attracting great interest for its role in isolating nanocellulose owing to its distinct advantages of biodegradability, low toxicity, and recyclability. Lignin‐containing cellulose nanocrystals (LCNCs) obtained using DES pretreatment has led to an improvement in the production of nanomaterials. Understanding the potential environmental impacts of this novel technology at the laboratory scale provides important insights to improve its sustainability at full scale in the future. This study evaluates the environmental impacts of the production of LCNCs from thermomechanical pulp (TMP) following acidic DES pretreatment (using a binary system of ‘choline chloride – oxalic acid dihydrate’ or a ternary system of ‘choline chloride – oxalic acid dihydrate – p‐toluenesulfonic acid’) based on various laboratory trials. The evaluation was conducted through a cradle‐to‐gate life‐cycle assessment for global warming potential (GWP), acidification potential (AP) and the cumulative energy demand (MJ). The average GWP, AP, and energy use were 39 kg CO2‐eq, 0.17 kg SO2‐eq, and 995 MJ per kg LCNCs, respectively. The sensitivity analysis showed that different degrees of reduction in environmental impact could be achieved by varying the input volume and/or reuse frequency of DES solutions. The largest reductions in GWP, AP, and energy use were achieved by reducing the input volume of DES solutions to 20% of its default value. The results of this LCA study illustrate the direction for future research and development (R&D) to further improve the sustainability of this DES‐mediated LCNC production technology. Through comparisons with the existing literature, this study also confirms the predominant contribution of chemical manufacturing to the overall environmental impacts of nanocellulose isolation technologies in general. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

Isolation and modification of nano-scale cellulose from organosolv-treated birch through the synergistic activity of LPMO and endoglucanases

Nanocellulose isolation from lignocellulose is a tedious and expensive process with high energy and harsh chemical requirements, primarily due to the recalcitrance of the substrate, which otherwise would have been cost-effective due to its abundance. Replacing the chemical steps with biocatalytic processes offers opportunities to solve this bottleneck to a certain extent due to the enzymes substrate specificity and mild reaction chemistry. In this work, we demonstrate the isolation of sulphate-free nanocellulose from organosolv pretreated birch biomass using different glycosyl-hydrolases, along with accessory oxidative enzymes including a lytic polysaccharide monooxygenase (LPMO). The suggested process produced colloidal nanocellulose suspensions (ζ-potential −19.4 mV) with particles of 7–20 nm diameter, high carboxylate content and improved thermostability (To = 301 °C, Tmax = 337 °C). Nanocelluloses were subjected to post-modification using LPMOs of different regioselectivity. The sample from chemical route was the least favorable for LPMO to enhance the carboxylate content, while that from the C1-specific LPMO treatment showed the highest increase in carboxylate content.

TAGUCHI ORTHOGONAL DESIGN FOR OPTIMIZING A UNIFIED TERNARY PROCESS TO VALORIZE OIL PALM LEAVES FOR NANOCELLULOSE ISOLATION

Oil palm leaves (OPL), as the major component of oil palm biomass, was capitalized for the isolation of nanocellulose (NC) by unified ternary acoustic, chemical- and enzyme-assisted techniques. This study aimed to statistically optimize the extraction parameters via the Taguchi Design for sonication time, duration of enzymatic hydrolysis, the concentration of acid, and the duration of acid hydrolysis, for the highest crystallinity of the isolated NC. The optimum condition required a sonication duration of 20 min, 1 h of acid hydrolysis in 6 M of H2SO4 and 1 h of enzymatic hydrolysis that resulted in the production of NC with a maximum 68.2% crystallinity index, based on X-ray diffraction (XRD) data. Duration of sonication time and acid hydrolysis was crucial for improving the crystallinity of isolated NC. The reduced C=O and C=C peaks at 1734 cm-1 and 1536 cm-1, respectively, in the Fourier-transform Infrared (FTIR) spectra of isolated NC, confirmed the removal of appreciable amounts of hemicellulose and lignin components in the OPL fibers. FESEM micrographs revealed the needle-like structures of NC with diameters between 21‒24.8 nm. The NC isolation approach presented here offers a promising avenue to ease the use of harsh acids for biomass pretreatment.

Adding Value to Spruce Bark by the Isolation of Nanocellulose in a Biorefinery Concept

It is shown that the isolation of nanocellulose in a biorefinery approach adds value to the bark and its components. The utilization of a chlorine-free delignification and the preparation of cellulose oxalate in a solvent-free process are an economic and environmentally advantageous way of applying the biorefinery concept and to use the bark in a sustainable way. The properties of cellulose oxalate from delignified bark were determined, and the morphological structure of the isolated nanocellulose was characterized. The chemical composition and thermal properties were monitored during the extraction and separation steps, and it was possible to prepare cellulose oxalate in a yield of 82% with a degree of substitution of 0.3 and surface charge of 1.53 mmol g–¹. The isolated nanocellulose was found to be a mixture of rodlike nanocrystals and nanofibrils. Initial thermal analysis of the isolated nanocellulose shows promising properties. The results show that the bark is a potential inexpensive source of high-value nanocellulose that can be isolated in high yield, for use in cosmetics or as reinforcement in nanocomposites. Since the isolated nanocellulose contains two different morphological types, it can be used where the properties of both cellulose nanocrystals and cellulose nanofibrils are required.

Ionic Liquids as a Sustainable Platform for Nanocellulose Processing from Bioresources: Overview and Current Status

The two-fold threats of the crisis of petrochemical industry-based plastics and serious environmental pollution have triggered the valorization of naturally occurring biopolymers to produce nanocellulose (NC). Nanocellulose has been used extensively in a variety of demanding applications due to its excellent features including biocompatibility, light weight, tunable surface properties, and improved environmental footprint. However, the sustainable production of NC is still confronted with bottlenecks to realize commercial feasibility due to poor solubility and hard processability of biopolymers using conventional hazardous solvents and reagents including concentrated sulfuric acid. The key might rest on the use of ionic liquids (ILs) that have induced a great deal of interest in recent years as powerful “green” solvents for biopolymer processing. ILs can be used as a catalyst and/or reaction medium and/or swelling agent for NC production with an eminent yield of high-quality NC under mild operating conditions coupled with proficient recoverability and recyclability. This review presents the recent technological developments of ILs-assisted proper valorization strategies of numerous bioresources for NC isolation and modification. The impact of IL cation/anion on structural changes of NC is also covered. The major advances in exploring ILs for NC surface modification reactions such as esterification, silylation, and surface plasticization as well as the microscopic insights of NC interaction with ILs are also reviewed. In view of the dominance of green chemistry principles for high purity of the recovered nanocellulose, close R&D endeavors for cheap and biodegradable ILs conjoined with emerging recycling techniques might boost sustainable commercialization.

Analysis of cellulose based nanocomposites & potential applications

Cellulose based nanocomposites have achieved a lot more attraction in recent years owing to its renewability, good mechanical strength and durability. The cellulose based nanocomposite development process typically involves extraction of cellulose from source materials such as wood, agricultural residue etc., isolation of nanocellulose from the cellulose and reinforcement of nanocellulose in polymers. This review outlines the various chemo-mechanical methods used for extraction of cellulose and for isolation nanocellulose. Also, the different methods used for fabrication of cellulose nanocomposites are discussed in details. Finally, the potential applications of nanocellulose composites different industries such as food and packaging, structural, bio- medical and electronics are also presented.

Lytic Polysaccharide Monooxygenase-Assisted Preparation of Oxidized-Cellulose Nanocrystals with a High Carboxyl Content from the Tunic of Marine Invertebrate Ciona intestinalis

The tunicate species Ciona intestinalis is a fast-growing marine invertebrate animal that contains cellulose in its outer part—the tunic. The high crystallinity and microfibril aspect ratio of tunicate cellulose make it an excellent starting material for the isolation of nanocellulose. In the present work, tunic from C. intestinalis was subjected to organosolv pretreatment followed by bleaching and acid-hydrolysis steps for the isolation of nanocrystals. Applying an intermediate enzymatic treatment step with a lytic polysaccharide monooxygenase (LPMO) from the thermophilic fungus Thermothelomyces thermophila was proved to facilitate the isolation of nanocellulose and to improve the overall process yield, even when the bleaching step was omitted. LPMOs are able to oxidatively cleave the glycosidic bonds of a polysaccharide substrate, either at the C1 and/or C4 position, with the former leading to introduction of carboxylate moieties. X-ray photoelectron spectroscopy analysis showed a significant increase in the atomic percentage of the C═O/O–C–O and O–C═O bonds upon the addition of LPMO, while the obtained nanocrystals exhibited higher thermal stability compared to the untreated ones. Moreover, an enzymatic post-treatment with LPMOs was performed to additionally functionalize the cellulose nanocrystals. Our results demonstrate that LPMOs are promising candidates for the enzymatic modification of cellulose fibers, including the preparation of oxidized-nanocellulose, and offer great perspectives for the production of novel biobased nanomaterials.

Isolation of nanocellulose from hemp (Cannabis sativa) fibers by chemo‐mechanical method and its characterization

AbstractNanocellulose of hemp fibers was obtained by employing the chemo‐mechanical technique, which included three stages of chemical treatments followed by mechanical grinding. Morphological analysis of untreated, treated, and nanocellulose of hemp fibers was performed by field emission scanning electron microscopy. Further, the crystalline behavior of these fibers was also measured by X‐ray diffraction and observed a higher crystallinity (80.95%) for the nanocellulose. Furthermore, change in chemical structure of fibers after chemical treatments and mechanical grinding was analyzed by Fourier transform infrared spectroscopy, and elimination of hemicelluloses and lignin was confirmed. Higher thermal stability of nanocellulose was confirmed by thermogravimetric analysis and differential scanning calorimetry analysis. The antibacterial analysis was also performed using Escherichia coli (E. coli) and bacillus bacteria. An excellent antibacterial property was offered by the isolated nanocellulose, which makes it a suitable reinforcement to be used in polymeric films and composites for the packaging applications.

The Effectivity of One-pot Concentrated Maleic Anhydride Hydrolysis for Betung Bamboo Pulp (Dendrocalamus asper sp)

Modification and synthesis of cellulose have attracted growing interest in the last decade due to applicable for many fields on advanced materials. Organic acid hydrolysis could be as an effective process for functionalization and size reduction of cellulose in one-pot reaction. The objective of this research is to study the effectivity of maleic acid anhydrous for functionalization and isolation of nanocellulose. Unbleached and Bleached Pulp of Betung Bamboo were used as cellulose resources. Concentrated maleic acid anhydride in 50% up to 60% (w/w) for 45 up to 90 minutes at 100 °C of reaction temperature were conducted to isolate cellulose nanocrsytals from betung bamboo pulp. Fibrillation treatment on fiber solid residue using ultrasonication result micrometers scale less than 1 μm for unbleached (UBB) and bleached (BB) fibrillated cellulose. Functionalization of carboxyl groups is more effective on UBB than BB with surface charge up to -48.5 mV and specific groups of carboxyl are detected in 1716 cm-1 and 1273 cm-1. Thermal stability also has similar tendency by Tonset in 313.69 °C and Tmax in 336.02 °C for UBB.

The current status of the enzyme-mediated isolation and functionalization of nanocelluloses: production, properties, techno-economics, and opportunities

The increasing interest for cellulose-based products has resulted in the development of processes for the controlled deconstruction of cellulose into cellulose nanomaterials, such as cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs). These nanomaterials can significantly increase the diverse applications of cellulose by exploring their nanometric scale options and improved properties for various high-volume, low-volume, and emerging/novel applications. Among the nanocellulose production processes, the enzyme-mediated methods are environment friendly and with expected lower capital and operating expenditures compared to traditional processes. In addition, it creates the unique possibility of fine-tuning the process to tailor nanocellulose properties that are suitable for specific applications. This review comprehensively examines the application of enzymes in the isolation of nanocelluloses. To date, no enzyme preparation for application to nanocellulose production is available commercially. Therefore, a fundamental understanding of potential enzymes focusing mainly on their differentiated properties, mechanism and alterations promoted to cellulose at different levels is first provided. This is to shed light on the enzyme properties that can be exploited for application in nanocellulose isolation. Then, the current state of the stand-alone and integrated enzyme-mediated processes is reviewed as well as the properties and yield of the isolated nanocelluloses in comparison to nanocelluloses obtained by traditional processes. In addition, the potential of enzyme-mediated functionalization has been discussed as a promising method that imparts unique properties to nanocelluloses, further diversifying their market. A detailed discussion on the challenges and opportunities for the major technical and economic factors that impact nanocellulose price has been included as well.

Isolation of nanocellulose from Saba’ (Musa acuminata x balbisiana) banana peel by one-pot oxidation-hydrolysis system

In the present study, facile one-pot production of nanocellulose from ripe and unripe Saba’ banana (Musa acuminata x balbisiana) peel was conducted by utilizing hydrogen peroxide (H2O2) as an oxidizing agent prior to hydrolysis with sulfuric acid (H2SO4) at different concentrations (8%, 24% and 40%). Proximate and chemical compositions of the ripe and unripe banana peel (BP) powder were analyzed, followed by physicochemical characterizations of the resulting nanocellulose by using Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy and Dynamic Light Scattering (DLS). FTIR analysis has confirmed the successful removal of non-cellulosic components from the BP through the distinguishable spectra of both the ripe and unripe BP powder with the H2O2/H2SO4- treated samples. SEM analysis revealed morphological changes of the BP powder from an irregular structure with a presence of starch granules to lamellar and fibrous structures after the H2O2/H2SO4 treatment and freeze-drying. The size of the nanocellulose is strongly influenced by the concentration of sulfuric acid used. Nanocellulose from ripe BP produced by using the 40% H2SO4 has the smallest size with D50 < 80 nm. These findings suggest the potential of banana peel, an abundant agricultural waste to be valorized into value-added materials with significant economic potentials.