Modification Of Nanocellulose Research Articles

Electron beam pretreatment of carboxymethyl nanofibrillar cellulose reinforced polyvinyl alcohol-based degradable composite membranes: Preparation, characterization and property optimization

This study investigated the development of biodegradable composite films blending carboxymethyl-modified peanut hull nanocelluloses (CMNCs) pretreated by electron beam irradiation with polyvinyl alcohol (PVA). The films were characterized by their structure, physicochemical properties, and degradation characteristics. The carboxyl group of CMNCs and the hydroxyl group of PVA enhance the network structure of the film through hydrogen bonding. This is most notably manifested in the fact that when CMNCs with a substitution degree of 0.38 and an addition amount of 4 % were added, the CMNCs were uniformly dispersed in the PVA matrix with a flat and smooth surface of the plastic and a dense structure. Meanwhile, the water contact angle (57.14°), the tensile strength (47.28 N/mm2) and elongation at break (156 %) of the composite films were significantly increased, and the water content (12.71 %) was decreased. The hydrophobic and mechanical properties of the composite plastics were improved considerably. In addition, the addition of 4 % CMNCs with a degree of substitution of 0.66 and a high dose of electron beam irradiation (120 KGy) to PVA made the degradation rate of the composite plastic in the first week (31 %) much higher than that of pure PVA (3 %). At the same time, the light transmittance of the composite plastic decreased significantly in both visible and UV ranges. EBI pretreatment significantly improved the degradation and light barrier properties of the composite plastics. Therefore, this study may provide new ideas for EBI pretreatment-assisted chemical modification of nanocellulose to prepare functional composite films.

Biofabrication of aminated nanocellulose reinforced polyvinyl alcohol/chitosan nanofibrous scaffold for sustained release of diltiazem hydrochloride

In the modern environment conscious era, there has been a huge demand for the effective green method to fabricate biomaterials for sustained transdermal release of diltiazem hydrochloride to treat hypertension and cardiac failure. In this vein, the present study explores the amination of waste jute sourced nanocellulose (ANC) and its effect as a reinforcing filler to design electrospun polyvinyl alcohol (PVA)/chitosan based polymeric nanofibrous scaffold for drug delivery. The characterization results of FTIR (Fourier Transform Infrared Spectroscopy) confirm the successful chemical modification of nanocellulose (NCC). SEM (Scanning Electron Microscopy) results indicate the morphological modifications in ANC due to grafting. ANC enhances the mechanical properties of scaffold and sustains the release of the loaded drug to 67.89±3.39% as compared to the pure PVA/chitosan scaffold of 92.63±4.63% over a period of 72 h as shown by the results of in-vitro drug release study. Moreover, the incorporation of 0.5 % ANC improves the anti-bacterial activity against both gram-positive (97.4±4.87%, reduction in viable cells count) and gram-negative bacteria (98.5±4.93%, reduction in viable cells count). Further, the skin irritation and MTT assay authenticate the biocompatibility of the developed scaffold. The overall findings hence prove the efficacy of the engineered scaffold as a potential transdermal patch for sustained drug delivery applications.

Lactic acid-facilitated surface modification of nanocellulose extracted from Borassus flabellifer leaves

Nanocellulose (NC) is revolutionizing the world of biopolymers. This research investigated the use of NC as an additive in polymer composites to enhance their structural and physio-chemical properties. The NC was extracted from Borassus flabellifer leaves and modified with lactic acid (LA). The leaves consisted of 62.2% cellulose, 15.8% hemicellulose, and 12.2% lignin by weight %. Alkali treatment was applied to obtain NCs with an average particle size of 317 nm. Characterization techniques, including SEM, FTIR, and XRD, are employed to evaluate the effectiveness of surface modification. The successful surface modification of NC with LA was confirmed by the presence of LA functional groups. XRD analysis revealed the crystalline nature of both the NCs and surface-modified NCs (SMNCs), with a higher crystalline index for the SMNCs (48.27%) than for the NCs (42.78%). The lower water absorption potential of SMNCs suggests their potential for use in biopolymer composites, demonstrating promising applications in materials science.

Nanocellulose as promising reinforcement materials for biopolymer nanocomposites: a review

Abstract. A green and sustainable development in world is important and it needs to further strengthen at the moment. In this aspect, biopolymers, biopolymers nanocomposites with biodegradable properties are the best way for this purpose. Nanocellulose (NC) is a biopolymer and can be produced from natural resources like various plant species and agricultural waste products including rice husk, tea leaves, sugarcane bagasse and so forth. Due to their special properties such as biodegradability, renewability, biocompability, low cost and outstanding mechanical capabilities, NC have gained increased research and application interests. This review provided detail information about the production, structure and properties of NC. The usage of NC as reinforcement materials for different types of biopolymers are presented in the review. The surface modification of NC for better dispersion and better interaction of NCs in polymer matrices, the mechanical and thermal properties of the NC biopolymers nanocomposites are discussed.

Highly efficient nanocellulose adsorbents

Adapting the use of nanocellulose as a sorbent is currently considered an extremely pressing problem, as synthetic analogues, although perform their functions well, are often toxic and incapable of biodegradation. In addition, the production of such synthetic sorbents is quite expensive. Therefore, today the production and modification of nanocellulose in order to increase their absorption capacity is especially important. Furthermore, a number of new applications of nanocellulose have been presented in nanocomposites, Pickering emulsions, wood adhesives, wastewater treatment, and emerging biomedical technologies. The problems and possibilities of new materials based on nanocellulose are being actively discussed. In the course of this work, a composite based on nanocrystalline cellulose from buckwheat, characterized by high sorption properties, environmental safety, and low cost of production, was obtained. Modification of cellulose was carried out with lactic acid. Nine groups of nanocrystalline cellulose samples with different acid soaking times were synthesized, and the optimal time required for the complete grafting of the acid into cellulose was determined. The specific surface area of the composite material was calculated using the Congo red dye adsorption method. It has been found that the specific surface area of the modified composite is not inferior to the specific surface area of many synthetic adsorbents, and even surpasses them in terms of environmental and economic indicators.

Preparation and modification of nanocellulose using deep eutectic solvents and their applications

Preparation and modification of nanocellulose using deep eutectic solvents and their applications

Preparation and Surface Modification of Nanocellulose and Its Adsorption Performance on Cu2+

Nanocellulose fibers (NCFs) were converted to cellulose nanocrystals (CNCs) and then modified with diethylenetriamine pentaacetic acid (DTPA) to form modified CNCs (DTPA–CNCs), which were investigated as adsorbents for removing Cu2+ from aqueous solution. The adsorption behavior was affected by pH, contact time, dosage and raw Cu2+ concentration. Langmuir model is the best method to fit the adsorption isotherm of experimental results. The optimal conditions for Cu2+ adsorption were 2 h at 35 °C and pH 3, the optimal adsorption capacity is 94.5 mg/g. These functional groups on the DTPA–CNCs provided enhanced adsorption capacity, compared with unmodified NCFs.

Surface modification of Nano cellulose: The path to advanced uses of smart and sustainable bio-material

In order to develop sophisticated applications for intelligent and sustainable biomaterials, our work focuses on the surface modification of nanocellulose. Nanocellulose has the ability to be modified to improve its surface characteristics, making it appropriate for a variety of uses in industries including biomedicine, packaging, textiles, and water treatment. There have been discussions on a number of physical and chemical surface modification approaches, including mechanical treatment, high-pressure homogenization, and chemical functionalization. The study also highlights the results of different characterization methods that were employed to examine the surface-modified nanocellulose. The review addresses the difficulties in integrating nanocellulose into many applications, despite its potential, including manufacturing scale-up, standardisation, and toxicity issues. The article's conclusion highlights the need for continuing research and development of nanocellulose-based materials in order to meet these obstacles and offer long-term solutions to a range of social issues.

A review of nanocellulose modification and compatibility barrier for various applications

Nanocellulose is increasingly important due to its abundance and sustainability sources, outstanding physicochemical properties, low density, high specific surface area, and easily modified surface chemistry. Nanocellulose is obtained from various sources, such as plants, algae, and bacteria, with plant-derived nanocellulose being the most common. Their presence significantly benefits many applications, especially in developing advanced materials for high end-use. Despite these benefits, the intrinsic hydrophilic behavior complicates dispersion in hydrophobic polymer matrices due to aggregation issues that result in deterioration properties. Nanocellulose modification and surface tuning are identified as fundamental approaches for improving the compatibility of the interfacial interaction between nanocellulose and polymer matrix to impart new functionalities to novel advanced materials. This article offers insight into nanocellulose by highlighting various lignocellulosic biomass sources and their chemical constituents. Three categories of nanocellulose are discussed in this review, including cellulose nanocrystals, cellulose nanofibrils, and bacterial nanocellulose. This article also featured several methods for promoting surface modification of nanocellulose to overcome the compatibility barrier between nanocellulose and polymer matrix to achieve a balanced hydrophilic-hydrophobic behavior. A few recent and emerging applications of nanocellulose-based composites are also presented in this review.

Modification of nanocellulose via atom transfer radical polymerization and its reinforcing effect in waterborne UV-curable resin

Cellulose nanocrystals (CNCs) are green reinforcing materials, and their potential has been evaluated in the preparation of waterborne UV-curable resin composites with high-performance. Herein, we present a novel and scalable approach for preparing surface-modified CNCs with acrylic-based polymers to strengthen the compatibility and interaction between CNCs and UV-curable resins. Using tert-butyl acrylate as the monomer, the nanocellulose grafted copolymer CNC-g-PtBA was successfully synthesized via atom transfer radical polymerization (ATRP) in the presence of a macromolecular initiator. Then, the CNC-g-PtBA is blended into the acrylic resin as a nanofiller to prepare the UV-curable nanocomposite. The results indicated that the contact angle of the CNCs increased from 38.7° to approximately 74.8°, and their thermal stability was significantly improved after graft modification. This contributed to the effective alleviation of the agglomeration phenomenon of nanocomposites due to the high hydrophilicity of pure CNCs. Notably, not only was the UV curing efficiency of the nanocomposites greatly increased but the mechanical properties were also further enhanced. Specifically, with the addition of 0.5 wt% CNC-g-PtBA, the curing time of the nanocomposite was shortened from >30 mins down to approximately 6 mins, and the bending strength was increased from 10 MPa for the original resin and 5 MPa for the addition of pure CNCs to 14.3 MPa, and the bending modulus was also greatly increased (up to approximately 730 MPa). Compared to pure CNCs, they are compatible with the resin, exhibiting high mechanical strength and flexibility, and have virtually no effect on the light transmission of the nanocomposites. Additionally, dielectric analysis (DEA) was used to monitor the dielectric constant and conductivity of the UV-curable nanocomposites in real time to further characterize their curing kinetics. The permittivity of these nanocomposites increased by 125 % compared to pristine resin, which shows potential for applications in high dielectric composites or for improving electrical conductivity. This work provides a feasible method for preparing UV-curable nanocomposites with high curing efficiency and permittivity, realizing a wider application of this high-performance nanocomposite.

The Potential of Nanocellulose Acetate as Surfactant for Water-Vegetable Oil Systems

Indonesia, as an agricultural country, has a variety of abundant plants. Cellulose is a component in plants that can be modified to increase its economic value. Resizing cellulose to nanocellulose and modification of nanocellulose to nanocellulose acetate can increase its potential as a surfactant. Resizing cellulose can be done using the strong acid hydrolysis method. An acetic anhydride reagent was utilized to convert the surface hydroxyl functional group into acetyl. The successful production and modification of nanocellulose were confirmed using fourier transform infrared and particle size analysis characterization. The infrared absorption spectrum of cellulose and nanocellulose showed no difference in peaks. Particle size distribution showed that nanocellulose I (CNC I) and nanocellulose II (CNC II) has sizes of 142 nm and 319 nm, respectively. The property of nanocellulose molecules in an oil-water system was simulated using molecular dynamics with GROMACS 2020.6 software. Appropriate trends can be seen in the interfacial tension of water-vegetable oil systems. The value of interfacial tension decreases with the addition of nanocellulose acetate compared to the addition of nanocellulose. With the agreement between the experimental and computational results, nanocellulose acetate can act as a surfactant.

Grafting of polyamines onto periodate oxidized nanocellulose, and its application to the fabrication of ionic nanopapers

Chemical modification of nanocellulose can be performed through a preliminary oxidation with sodium periodate followed by a reductive amination. Herein, we investigated the specific reactivity of polyallylamine and polyvinylamine, which are known as wet and dry strength agents for cellulosic fibrous networks. In comparison to water at neutral pH, it was observed that the grafting of both polyamines is promoted at basic pH or in DMSO. It was also evidenced that the amount of grafted polyamine can be adjusted by varying the nanocellulose oxidation degree. At last, translucent nanopapers were obtained by combining such chemistry with solvent casting resulting in the formation of membranes containing up to 3 mmol.g−1 of ionic groups. Once hydrated, their swelling degree stayed below 200% while their ionic conductivity reached 1 mS.cm−1.

Understanding Nanocellulose-Water Interactions: Turning a Detriment into an Asset.

Modern technology has enabled the isolation of nanocellulose from plant-based fibers, and the current trend focuses on utilizing nanocellulose in a broad range of sustainable materials applications. Water is generally seen as a detrimental component when in contact with nanocellulose-based materials, just like it is harmful for traditional cellulosic materials such as paper or cardboard. However, water is an integral component in plants, and many applications of nanocellulose already accept the presence of water or make use of it. This review gives a comprehensive account of nanocellulose-water interactions and their repercussions in all key areas of contemporary research: fundamental physical chemistry, chemical modification of nanocellulose, materials applications, and analytical methods to map the water interactions and the effect of water on a nanocellulose matrix.

Reducing end modification of nanocellulose as a novel approach for high-performance sustainable composites

The development of nanocellulose sustainable materials is considered as one of the most promising alternatives to address plastic pollution issues, as global plastic wastes may increase to 11 billion tonnes by 2025. However, how to achieve the homogeneous dispersion of nanocelluloses (CNCs) and strong interfacial interactions with matrix materials, while well maintaining its percolation networks, is a challenge in this field. As opposed to the conventional surface chemical modification strategy, the reducing end modification of CNCs as a novel approach provides an opportunity to achieve this objective, which also opens a new door for the design of stimuli-responsive CNC sustainable composites, such as vitrimer materials and stimuli-responsive Pickering emulsions.

Sustainable nanocomposite coating for moulded pulp with enhanced barrier properties for food packaging applications

AbstractDue to poor barrier properties and high sensitivity to moisture, the applications of paper‐based food packaging remain limited. While gaining high barrier performance and surface durability, laminating papers with binders and other materials often leads to reduced recyclability and sustainability. Herein, we present a promising approach to improve the barrier properties and surface oil resistance of bagasse moulded pulp while preserving its green profile. A bio‐nanocomposite layer, combining nanocellulose and shellac (natural polyester), was coated on the surface of moulded pulp. This nanocomposite coating layer provides excellent gas barrier and water barrier performance simultaneously, thanks to the ester modification of nanocellulose to improve its hydrophobicity. With a good compatibility and dispersion in the shellac matrix phase, the modified nanofibrillated cellulose demonstrated an improved barrier performance compared with the unmodified nanofibrillated cellulose. Oxygen transmission rate and water vapour transmission rate of the coated pulps were in the range 60–300 cm3 m−2 day−1 and 10–30 g m−2 day−1, respectively, comparable to those of conventional food packaging materials. The surface resistance of the coated pulps was also greatly improved, indicated by the water contact angle, oil contact angle, Kit test and oil resistance test in a bowl model. The nanocomposite was able to enhance the tensile strength of the moulded pulp by 23%. In summary, the current sustainable nanocomposite coating layer demonstrated great potential in converting paper‐based materials to high barrier and sustainable food packaging. © 2022 Society of Industrial Chemistry.

Preparation of BTCA‐esterified cellulose nanocrystals and effects on mechanical and thermal properties of polypropylene composites

AbstractIn this study, cross‐linked cellulose nanocrystals (CNC) were esterified using 1,2,3,4‐tricarboxylic acid (BTCA) to decrease the hydroxyl content of the nanocellulose, control its hydrophilic/hydrophobic degree, and improve its compatibility with the polypropylene (PP) matrix. The mechanical and physical properties of nanocellulose‐reinforced polypropylene composites were investigated after they were manufactured via melt extrusion using a twin‐screw extruder. FTIR and XPS analysis revealed that the nanocellulose chain was successfully esterified utilizing BTCA. The results from SEM and Mapping demonstrated that the nanocellulose was spread equally throughout the matrix. By characterizing the 5 wt% CNC/PP composite material with DMA and tensile testing devices, the elongation at break decreases, the rigidity increases, and the tensile strength increases to 50.5 MPa, a 25.5% increase over pure polypropylene. Simultaneously, DSC data demonstrated that nanocellulose provided a heterogeneous nucleation site, expedited polypropylene crystallization, and was advantageous for polypropylene processing. According to the results of TG/DTG, esterified CNC/PP composites containing 5% CNC had the highest thermal resistance, with Tonset and Tmax increasing by up to 66 and 11.6°C, respectively, when compared to pure PP. Following a thorough investigation and evaluation of the samples' mechanical and thermal properties, it was determined that BTCA esterification cross‐linking is an effective method for surface modification of nanocellulose, as it increases the compatibility of nanocellulose with polypropylene, improves the mechanical properties of polypropylene, and thus expands its application range.

Progress and Prospects of Nanocellulose-Based Membranes for Desalination and Water Treatment.

Membrane-based desalination has proved to be the best solution for solving the water shortage issues globally. Membranes are extremely beneficial in the effective recovery of clean water from contaminated water sources, however, the durability as well as the separation efficiency of the membranes are restricted by the type of membrane materials/additives used in the preparation processes. Nanocellulose is one of the most promising green materials for nanocomposite preparation due to its biodegradability, renewability, abundance, easy modification, and exceptional mechanical properties. This nanocellulose has been used in membrane development for desalination application in the recent past. The study discusses the application of membranes based on different nanocellulose forms such as cellulose nanocrystals, cellulose nanofibrils, and bacterial nanocellulose for water desalination applications such as nanofiltration, reverse osmosis, pervaporation, forward osmosis, and membrane distillation. From the analysis of studies, it was confirmed that the nanocellulose-based membranes are effective in the desalination application. The chemical modification of nanocellulose can definitely improve the surface affinity as well as the reactivity of membranes for the efficient separation of specific contaminants/ions.

Hydrogen bond–induced aqueous-phase surface modification of nanocellulose and its mechanically strong composites

Hydrogen bond–induced aqueous-phase surface modification of nanocellulose and its mechanically strong composites

Functionalization of nano-cellulose by coupling agent with green strategy

Nano-cellulose is widely used in the fields of double-hydrophobic interface fabric, high-grade protective clothing, chemical industry and medicine. Although the research of nano-cellulose has received widespread attention, because of its strong intermolecular force, its dispersion in the medium is not ideal. In order to further increase the dispersion of nano-cellulose in the medium, one of the methods used is to weaken the hydrogen bonding between nano-cellulose by chemical route. In this work, nano-cellulose is simply modified by coupling agent in environment-friendly solvent. Different analytical methods are used to verify the successful modification of nano-cellulose. The results show that the dispersibility of the modified nano-cellulose in water is improved, and the thermal stability is enhanced in the range of 300–567℃. It is worth remarking that the transmittance of the modified nano-cellulose in visible light still remains above 85%. This study provides a feasible, simple and environmental-friendly strategy for developing the application of nano-cellulose, especially in the field of photopolymerization, radical polymerization and cross linking reaction.

Superhydrophobic modification of nanocellulose based on an octadecylamine/dopamine system

We prepared super-hydrophobic nanocellulose films using a non-toxic octadecylamine/polydopamine system. Octadecylamine, a low surface energy material, was used to provide hydrophobic alkyl long chains. Polydopamine was produced by dopamine under alkaline conditions, creating an adhesive substance, which reinforced the hydrophobic long chains and increased the surface roughness of nanocellulose. The effects of reagent concentration, reaction temperature, and reaction time on hydrophobicity were then investigated. The results showed that with a 1:1 mass ratio of nanocellulose to octadecylamine, and reacting at 60 °C for 4 h, the contact angle of the obtained composite membrane reached 168.2°. Scanning electron microscope images revealed that the modified nanocellulose had a smaller particle size and more uniform distribution, which effectively improved the hydrophobicity of the nanocellulose. Thus, the green preparation of superhydrophobic films with high-temperature resistance and wear resistance was realized, which contributed to the high-value utilization of nanocellulose.