Extraction Of Cellulose Nanocrystals Research Articles

Extraction optimization and molecular dynamic simulation of cellulose nanocrystals obtained from bean forage

The structural, energetic, and mechanical characteristics of cellulose were evaluated through molecular dynamic simulation on atomic scale in view of different applications. This research standardized the processing variables for the extraction of cellulose nanocrystals obtained from bean forage; the optimal conditions for the alkaline and bleaching treatments were: NaOH 1.75% w/w for 8.5 h with a bleaching time of 1 h at 70 °C with a yield of 25.51%; for the acid treatment the optimal conditions obtained were: H2SO4 at 55% for 30 min at 40 °C; in this case, the optimization was carried out with two responses: yield (60.68%) and crystallinity index (49.36%). The raw material was chemically characterized showing a cellulose content of 45.78 ± 0.888% wt. cellulose, 10.73 ± 0.732% wt. hemicellulose, 5.09 ± 0.753% wt. lignin, and other components. X-ray diffraction indicated changes in the diffraction patterns corresponding to the crystalline and amorphous areas of the cellulose. The percentages of crystallinity obtained with the optimal conditions were: 40.39% after the alkaline treatment, 42.02% after the bleaching treatment, and 49.36% after the acid treatment. Finally, the structure and molecular dynamics of cellulose nanocrystals obtained from bean forage created with Materials Studio 8.0 program were evaluated, in which geometric optimization was carried out applying the Quasi-Newton BFGS method. X-ray diffractograms generated by the program were compared against those obtained experimentally, validating the virtual structure of the nanocrystals by obtaining a similarity of 86%, which would allow exploratory research using molecular dynamics to find possible applications.

Extraction of cellulose nanocrystals from red banana peduncle agro‐waste and application in environmentally friendly biocomposite film

AbstractThe agricultural waste dumped onto the land is creating an environmental problem. The conversion of those easily available agro‐wastes into value‐added nano reinforcement materials for biopolymers is an alternative method of waste utilization and minimization. In the current study, the red banana peduncle (RBP) waste was used as a precursor in the extraction of carboxylated cellulose nanocrystals (CCNCs) by alkalization, acidified chlorination citric acid hydrolysis, as well as the assessment of its reinforcing capability in polyvinyl alcohol. The characterization of the extracted CCNCs is analyzed through electron microscopy, X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), and Thermogravimetric analysis (TGA), respectively. The CCNCs exhibit a rod‐like shape (235 ± 20 nm length and 17.2 ± 6 nm width) with a high crystallinity of 89.7%, a negative zeta potential (−48 mV), and good thermal resistivity against degradation up to 280 °C. Furthermore, the effects of CCNCs integration on the bionanocomposite films' tensile, optical, bio decomposition, and thermal behavior were examined. The bionanocomposite film with improved physical, functional, thermal and bio decomposition characteristics offers the possibility for active packaging applications.

Green Extraction of Cellulose Nanocrystals of Polymorph II from Cynara scolymus L.: Challenge for a “Zero Waste” Economy

The increase of agri-food wastes by agriculture and industries is one of the main causes of environmental pollution. Here we propose the recycling of Cynara scolymus L. wastes to obtain polymorph II cellulose nanocrystals (CNC). Two different extraction procedures are compared: (i) Soxhlet extraction in an ethanol/toluene mixture, and (ii) water boiling of the agricultural waste. Both procedures were followed by purification of cellulose fibers through bleaching treatments and extraction of cellulose nanocrystals by acid hydrolysis. CNCs have been extensively characterized by FTIR spectroscopy, electrophoretic light scattering measurements, X-ray powder diffraction methods, transmission electron microscopy, and thermogravimetric analyses. Extracted CNC are rod-like-shaped polymorph IIs with a good crystallinity index, and they are characterized by high hydrogen bonding intensity. The ELS measurements on samples from both procedures show good results regarding the stability of the CNC II sol (ζ < −40 ± 5 mV), comparable to that of the CNC polymorph I. Both polymorph II CNCs show better thermal stability, compared to CNC I. The results show that the easy extraction procedure from agricultural Cynara scolymus L. waste can be used to produce high-quality cellulose nanocrystals as a green alternative to the commonly used synthetic route.

Lignocellulosic Biomass Waste-Derived Cellulose Nanocrystals and Carbon Nanomaterials: A Review.

Rapid population and economic growth, excessive use of fossil fuels, and climate change have contributed to a serious turn towards environmental management and sustainability. The agricultural sector is a big contributor to (lignocellulosic) waste, which accumulates in landfills and ultimately gets burned, polluting the environment. In response to the current climate-change crisis, policymakers and researchers are, respectively, encouraging and seeking ways of creating value-added products from generated waste. Recently, agricultural waste has been regularly appearing in articles communicating the production of a range of carbon and polymeric materials worldwide. The extraction of cellulose nanocrystals (CNCs) and carbon quantum dots (CQDs) from biomass waste partially occupies some of the waste-recycling and management space. Further, the new materials generated from this waste promise to be effective and competitive in emerging markets. This short review summarizes recent work in the area of CNCs and CQDs synthesised from biomass waste. Synthesis methods, properties, and prospective application of these materials are summarized. Current challenges and the benefits of using biomass waste are also discussed.

One-step extraction of cellulose nanocrystals from high lignin biomass through ammonium persulfate oxidation method

Cellulose nanocrystals (CNCs) are one of the emerging nanomaterials that have several interesting and unique properties such as high mechanical strength (Young modulus of 100–140 GPa), low density (1.6 g cm−3), and large surface area (150–250 m2 g−1) that are advantageous in a myriad of applications. In this study, CNCs were successfully prepared from empty fruit bunch (EFB), an agricultural waste from palm oil, using a one-step extraction method using ammonium persulfate oxidation. EFB was directly reacted with ammonium persulfate (APS) at different concentrations (1.0; 1.5 and 2.0 M) at 60 °C for 15 h to undergo the oxidation. The oxidised EFB samples were characterised by dynamic light scattering (DLS), x-ray diffraction (XRD), transmission electron microscope (TEM), Fourier-transform infrared (FTIR), and thermogravimetric analysis (TGA). The FTIR result shows that lignin and hemicellulose in the EFB were successfully removed using one-step extraction method with minimum APS concentration of 1.5 M. The CNCs product has a crystallinity index of 64.1%, a crystallite size of 3.86 nm, and (0 0 2) plane lattice spacing of 3.95 Å. Based on the lattice spacing calculation of all samples, the crystalline structure of cellulose does not change during the oxidation process. The proposed one-step extraction method has been proven to produce the CNCs from EFB with a crystallinity index of 64.1%, a length of 275.9 ± 82.8 nm, and a diameter of 25 ± 5.3 nm.

Poly(ε-caprolactone) blended with thermoplastic waxy starch matrix reinforced with cellulose nanocrystals from Macauba (Acrocomia spp.) Rachis

Aiming at a sustainable bionanocomposites, cellulose nanocrystals (CNCs) were extracted by acid hydrolysis from rachis fibers of macauba (Acrocomia spp.) palm trees natural of the Brazilian Pantanal. In a second step, CNCs were incorporated as reinforcement into thermoplastic waxy starch (TPS) phase blended with poly(ε-caprolactone) (PCL), 70/30 (w/w), by higher shear rate co-rotating extrusion. Nanocomposites were formulated with 3.25, 6.5 and 13 wt% CNCs in relation to TPS mass. The nanocomposite containing only 3.25 wt% CNCs improved the mechanical tensile strength by three times and the elastic modulus by more than six times in relation to the TPS/PCL matrix, reaching values close to 12 MPa and 1 GPa, respectively. In addition, the lower amount of CNCs guaranteed the thermal stability of the TPS/PCL nanocomposites (~250 °C), showing an increase in Tonset of 20 °C in relation to the neat matrix. This effect may be associated with the interactions between TPS molecules and CNCs, as observed in the rheological measurements. Therefore, this study showed the potential of macauba as a renewable source for CNC extraction, bringing higher economic value to this plant and establishing its sustainable productive chain.

Ultrafast and energy-saving extraction of cellulose nanocrystals

This study provides an innovative idea for shortening CNC extraction times from hours to minutes via a green, high-efficiency and energy-saving pathway.

Improving Dyeing Properties of Cotton Fabrics to Natural Dyes with Cellulose Nanocrystals (CNCs) [Mejora de las propiedades de teñido de telas de algodón a tintes naturales con nanocristales de celulosa (CNC)

Natural dyes can make less environmental problems associated with manufactured colouring agents and textile dyeing. But, the natural dyes fixing process was used chemicals called mordant. The most of times mordants were used metallic salts and metal salts mordants were not environmentally friendly. Therefore, remove the disadvantage associated with natural colorants and the use of nanoparticles. In this research, cotton fabric was treated with the nanoparticle of cellulose nanocrystals (CNCs) as mordant. The cellulose nanocrystals extraction process was done by using Whatman filter paper. The cellulose nanocrystals obtained will be further analyzed and characterized by using selected tools such as Particle size analysis and Fourier-transform infrared (FTIR) spectroscopy. The cotton fabrics mordanting processes were done by two types of pre-mordanting and post-mordanting methods. The three natural ingredients of Mangifera indica (Mango) leaves, Tectona grandis (Teak) leaves and Lannea coromandelica (Indian ash tree) leaves were used to extract the natural dyes using with aqueous extraction method. The extracts from dyeing processes were carried out after and before mordanting processes. The dyed sample from colour fastness to light, washing, and crocking were assessed according to standard methods. The cellulose nanocrystals gave very good colour fastness to light, wash, and rubbing when dyed with all three dye extractions. In the present study, innovative mordant of cellulose nanocrystals and natural dyeing with three natural dye extractions have been shown to give good dyeing results with cotton fabric.

Preparation and Characterization of corn husk nanocellulose coating on electrospun polyamide 6

At present, electrospinning technology is a versatile and simple method for generating nano-scale membranes, and it provides attractive solutions in solving environmental problems and many energy problems. However, such films generally have low mechanical properties which limit their use in industry. Nanocellulose with excellent mechanical properties, high specific surface area, and renewable nature is an ideal green reinforcing material. In this paper, the cellulose nanocrystals (CNC) coatings on electrospun polyamide 6 (PA6) were prepared via coating method and explored as potential high-performance reinforced materials. The extraction of CNC and the performance of the composite membranes were studied by calculating the yield, scanning electron microscopy, 3D imaging, mechanical testing, and thermogravimetric analysis. Results show that the yield of CNC is impacted by various factors among which acid concentration is the most important. The CNC/PA6 composite film shows lower porosity and higher surface roughness than the pure PA6 membrane. With the increase of CNC concentration, lower porosity and higher surface roughness are obtained. With CNC coatings, tensile strength and Young s modulus of PA6 increase dramatically, while the tensile strain decreases obviously. The Young s modulus of the composite film has been increased by 250%. The composite membranes reveal high mechanical strength and low porosity, which can be applied infiltration and packaging.

A review on cellulose nanocrystals production and characterization methods from Elaeis guineensis empty fruit bunches

Cellulose nanocrystals with various functionalities have received significant interest in recent years due to their wide applications. Elaeis guineensis empty fruit bunches (EFB) have been explored by researchers as one of the potential sources for cellulose nanocrystals extraction in recent years. However, cellulose nanocrystals extraction methods using EFB as raw materials are yet to be evaluated based on technical, economic and environmental aspects. Thus, this study aims to assess the effect of EFB pretreatment methods, cellulose nanocrystals isolation methods, with or without any post-treatment, towards the final properties of cellulose nanocrystals. Characterization methods suitable for evaluating the properties of cellulose nanocrystals extracted from EFB are suggested and supported with data from other similar studies. In brief, sulphuric acid hydrolysis exhibits a more significant advantage in cellulose nanocrystals conversion yield and stable suspension than other treatments when empty fruit bunch fibres are used as the cellulose source. By evaluating the benefits or limitations of extraction and characterization methods, future studies on the cellulose nanocrystals extraction from EFB could be further enhanced to prepare a more efficient cellulose nanocrystals extraction from EFB at a commercial scale.

Extraction of cellulose nanocrystals from areca waste and its application in eco-friendly biocomposite film

Areca nut husk fibers are easily available and they are abundant agricultural waste, whose utilization to high value products needs more attention. The present study aims at the extraction of cellulose nanocrystals (CNCs) from areca nut husk fibers and the evaluation of its reinforcement capacity in polyvinyl alcohol (PVA) and chitosan (CS) film. The CNC showed rod-like structures, which were confirmed by TEM and AFM analysis. The diameter of the isolated CNC was 19 ± 3.3 nm; the length was about 195 ± 24 nm with an aspect ratio of 10.2 ± 6.8. The zeta potential of CNC was −15.3 ± 1.2 mV. Fourier Transform Infrared Spectroscopy analysis showed that the non-cellulosic compounds were effectively eliminated, and the X-ray diffraction results showed that CNC had higher crystallinity than the raw, alkali, and the bleached fibers. Thermogravimetric analysis revealed good thermal stability for the CNC. Moreover, the effects of the incorporation of CNC on the optical and tensile behaviours of the bionanocomposite film were investigated. The bionanocomposite film retained the same transparency as the PVA/CS film, indicating that the CNC was disseminated evenly in the film. The incorporation of CNC (3 wt%) to the PVA/CS film enhanced the tensile strength of the bionanocomposite film (9.46 ± 1.6 MPa) when compared to the control films (7.81 ± 1.4 MPa). Furthermore, the prepared nanobiocomposite film exhibited good antimicrobial activity against foodborne pathogenic bacteria and postharvest pathogenic fungi. These findings suggest that the bionanocomposite film might be suitable for food packaging applications.

Sustainable and superhydrophobic cellulose nanocrystal-based aerogel derived from waste tissue paper as a sorbent for efficient oil/water separation

Extraction of cellulose nanocrystals (CNCs) from wastes is a valuable strategy from the environmental and economical points of view. Herein, a novel and cost-effective method for the preparation of superhydrophobic, environmentally friendly, and recyclable bio-aerogel by freeze-drying the aqueous suspension of CNCs extracted from waste tissue paper and polyvinyl alcohol (PVA) in the presence of hydrolyzed tetraethyl orthosilicate (TEOS) sol has been developed for the first time. The highly porous (98.42 %), ultralow density (0.017 g/cm3), and superhydrophobic (WCA of 154.93°±4.14) CNCs/PVA/TEOS aerogel can selectively remove oily contaminants from water (BET surface area of 76 m2/g). The aerogel showed a high sorption capacity in the range of 69−168 g/g for 6 oils and 8 organic solvents. The reusability experiments showed the aerogel could maintain more than 92 % of its sorption capacity even after 20 cycles of sorption-squeezing. The cyclic compressive stress-strain tests confirmed the good mechanical properties of the aerogel with 89 % of shape recovery after 50 cycles. The CNCs/PVA/TEOS aerogel can be used as a recyclable sorbent for removing oils/organic solvents from water.

Extraction of cellulose nano-crystals from Polyalthia longifolia and Terminalia catappa leaf litter and the synthesis of low-cost CNC-based hydrogel for articular cartilage

Due to the rise in demand for biodegradable and renewable materials, the synthesis of CNCs from lignocellulosic biomass opens up a new avenue for the creation and application of novel materials in nanotechnology. The CNC-based hydrogels appear to be a favorable material in various applications due to their excellent mechanical strength, biodegradability, biocompatibility, and low toxicity. This work aimed to utilize the fallen leaves for the extraction of Cellulose Nano-crystals (CNC) from Polyalthia longifolia and Terminalia catappa leaf litter. Leaves mainly consist of cellulose hence used for the extraction of nanocellulose. Alkali treatment was performed with aqueous sodium hydroxide, followed by bleaching with aqueous sodium chlorite. Sulphuric acid hydrolysis was used for the extraction of CNC. The morphology, structure, functional groups, and crystallinity of the retrieved CNC were studied using a Transmission Electron Microscope (TEM), Fourier Transformed Infrared spectroscopy (FTIR), and X-Ray Diffraction (XRD). The shape was rod-like for both P. longifolia and T. catappa and the CNC’s crystallinity index was enhanced to 72.40% and 73.95%, respectively. The TEM micrographs revealed that the impurities present on the leaf fibres were successfully removed by alkali treatment and subsequent bleaching further purified the fibres, leaving behind mostly cellulose while the hemicellulose and lignin were removed, which was revealed in FTIR spectra. The obtained CNC was used in the preparation of hydrogel by cross-linking with natural polymers like sodium alginate and gelatin. A Freeze-thawing process was carried out for the fabrication of hydrogel. The resulting hydrogel can be used as a substitute for cartilage applications.

Extraction of cellulose nano-crystals from Polyalthia longifolia and Terminalia catappa leaf litter and the synthesis of low-cost CNC-based hydrogel for articular cartilage

Extraction of cellulose nano-crystals from Polyalthia longifolia and Terminalia catappa leaf litter and the synthesis of low-cost CNC-based hydrogel for articular cartilage

Extraction of cellulose nanocrystals and fabrication of high alumina refractory bricks using pencil chips as a waste biomass source

Extraction of “green” cellulose nanocrystals (CNCs) from waste biomass is a sustainable strategy for high valued valorization in the view of socio-economic and environmental issues. Herein, for the first time, waste pencil chips (PC) as a potential source of cellulose, were used for the extraction of CNCs. CNCs were successfully extracted from PC wastes using alkali and bleaching chemical treatments to remove hemicellulose and lignin followed by acid hydrolysis using concentrated sulfuric acid. The products after each step were characterized in terms of crystallinity, chemical structures, thermal properties, and morphologies. The XRD results showed that the crystalline index increased about 16% from PC (75%) to CNCs (91%). The FTIR analysis confirmed the removal of the hemicellulose and lignin from PC after alkali and bleaching treatments. The TGA analysis showed that the thermal stability of the CNCs is affected mainly by the dehydration reaction caused by sulfate groups. The SEM and FE-SEM images showed that after chemical treatments, defibrillation of fibers occurs and CNCs have a needle/rod like structure. Also, the specific surface aera was greatly increased from 0.495 for PC to 486.430 m2/g for CNCs. Herein, for the first time, lignin-containing cellulose extracted from PC was replaced with sawdust (SRB) in the production of alumina refractory bricks (RBs), as a pore former/binder. Interestingly, the prepared RBs (PC–NaOH/RB) had a greater amount of alumina (83%) and a lower density (0.75 g/cm3) than SRB. The classification temperature increased from 1650 for SRB to 1717 °C for PC-NaOH/RB.

Cotton Wastes Functionalized Biomaterials from Micro to Nano: A Cleaner Approach for a Sustainable Environmental Application.

The exponential increase in textile cotton wastes generation and the ineffective processing mechanism to mitigate its environmental impact by developing functional materials with unique properties for geotechnical applications, wastewater, packaging, and biomedical engineering have become emerging global concerns among researchers. A comprehensive study of a processed cotton fibres isolation technique and their applications are highlighted in this review. Surface modification of cotton wastes fibre increases the adsorption of dyes and heavy metals removal from wastewater. Cotton wastes fibres have demonstrated high adsorption capacity for the removal of recalcitrant pollutants in wastewater. Cotton wastes fibres have found remarkable application in slope amendments, reinforcement of expansive soils and building materials, and a proven source for isolation of cellulose nanocrystals (CNCs). Several research work on the use of cotton waste for functional application rather than disposal has been done. However, no review study has discussed the potentials of cotton wastes from source (Micro-Nano) to application. This review critically analyses novel isolation techniques of CNC from cotton wastes with an in-depth study of a parameter variation effect on their yield. Different pretreatment techniques and efficiency were discussed. From the analysis, chemical pretreatment is considered the most efficient extraction of CNCs from cotton wastes. The pretreatment strategies can suffer variation in process conditions, resulting in distortion in the extracted cellulose’s crystallinity. Acid hydrolysis using sulfuric acid is the most used extraction process for cotton wastes-based CNC. A combined pretreatment process, such as sonication and hydrolysis, increases the crystallinity of cotton-based CNCs. The improvement of the reinforced matrix interface of textile fibres is required for improved packaging and biomedical applications for the sustainability of cotton-based CNCs.

Extraction of Cellulose Nanocrystal from Multilayer Packaging Residues Composed of a Mixture of Eucalyptus and Pine Fibers

This study takes advantage of a residue from the multilayer packaging recycling process as a raw material for the extraction of cellulose nanocrystals in just three purification steps: pulping with acetic acid, bleaching with hydrogen peroxide, and acid hydrolysis with sulfuric acid. The nanocrystals obtained from the multilayer packaging showed high crystallinity (77%), and transmission electron microscopy revealed 71% of the nanocrystals with an aspect ratio between 24 and 64. XRD revealed that pulping treatments with acetic acid removed carbonate calcium from the paperboard, and bleaching, together with acid hydrolysis, contributed to the gradual reduction of kaolin, components present in the multilayered paperboard manufacture. Therefore, without the use of additional purification steps, these components were gradually reduced until their detection by XRD is not possible. The thermogravimetric analysis showed good stability of the cellulose nanocrystals (Tonset = 190 °C and Tmax = 245 °C), allowing their future application in nanocomposites.

Efficient recovery of the dyed cotton–polyester fabric: cellulose nanocrystal extraction and its application in composite films

Herein, cotton fiber and polyester fiber were separated from their blended fabric by a dilute acid pretreatment combined mechanical grinding process with a total recovery rate of 92.1 %. The recovered cotton fiber was bleached and used to extract cellulose nanocrystals (CNCs). Compared with those extracted from the never-used cotton fibers, the resultant CNCs are lower in aspect ratio, higher in aqueous transparency and better in dispersion stability. Furthermore, the as-prepared CNCs, together with silica nanoparticles, were employed as the reinforcements to fabricate films with methylcellulose. The addition of the nanofillers endowed the pure methylcellulose films with a 200% improvement in tensile strength while slightly affected the transparency of the films. High-efficient recovering of dyed natural/synthetic fiber blended textiles, high-quality CNC extraction, and high-performance composite film fabrication achieved in this work is conducive to the utilization of waste resources and the saving of primary resources.

Cellulose Nanocrystals: Obtaining and Sources of a Promising Bionanomaterial for Advanced Applications

Cellulose nanomaterials are one of the most relevant scientific-technological discoveries in recent years. Cellulose nanocrystals (CNCs) stand out among them because their extraordinary chemical, mechanical, thermal, and optical properties make them an interesting alternative to manufacture advanced materials from the most abundant biopolymer on Earth. This work presents a critical analysis of the literature published in the last years, emphasizing the various obtaining processes that have emerged in the search for greener methods. A comparative table of the processes used in the extraction of CNCs from various sources (non-edible biomass and agro-industrial wastes) is included, indicating the process’s effectiveness and the characteristics and applications of this sustainable advanced bionanomaterial.

Isolation and characterization of cellulose nanocrystals (CNCs) from industrial denim waste using ammonium persulfate

This research focuses on extraction of cellulose nanocrystals (CNCs) from industrial denim waste using oxidation method in a batch reactor by varying pretreatment methods, ammonium persulfate (APS) concentrations, and reaction times. This oxidation method shows beneficial when compared to the conventional hydrolysis methods in term of less corrosive and shorter extraction time. Two-step method was developed instead of using one-step only to judge the beneficial of alkali pretreatment. The raw material of industrial denim waste was prepared in the form of powder with particle size range of 80–120 mesh. This raw material was characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Thermogravimetric analysis (TGA). The CNCs products were characterized using Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), and X-ray Diffraction (XRD) for confirming the particle size distribution, morphology, and crystallinity, respectively. The results showed that increasing the reaction time from 5 h to 15 h decreased the particle size of CNCs and increased the crystallinity of CNCs, while increasing the APS concentration from 1 to 1.5 M decreased the particle size of CNCs and the crystallinity of CNCs. The optimum operating conditions were obtained that the reaction time was 15 h at 60 °C and 1.5 M APS concentration, which produced the rod like morphology of CNCs with 76.14 ± 8.56 nm length, 18.10 ± 3.54 diameter and the crystallinity of 83 %. From the DLS and XRD characterizations, it was confirmed that the CNCs from denim waste could be produced through the oxidation method using APS.