A review on the emerging applications of cellulose, cellulose derivatives and nanocellulose in carbon capture

Continuously enhanced versatile nanocellulose films enabled by sustaining CO2 capture and in-situ calcification

Cellulose possesses numerous favorable peculiarities to replace petroleum-based materials. Nevertheless, the extremely high hygroscopicity of cellulose severely degrades their mechanical performance, which is a major obstacle to the production of high-strength, multi-functional cellulose-based materials. In this work, a simple strategy was proposed to fabricate durable versatile nanocellulose films based on sustaining CO2 capture and in-situ calcification. In this strategy, Ca(OH)2 was in-situ formed on the films by Ca2+ crosslinking and subsequent introduction of OH-, which endowed the films with high mechanical strength and carbon sequestration ability. The following CO2 absorption process continuously improved the water resistance and durability of the films, and enabled them to maintain excellent mechanical properties and promising light management ability. After a 30-day CO2 absorption process, the water contact angle of the films can be increased from 43° to 79°, and the weight gain rate of the films in a 30 h water-absorption process can be sharply decreased from 331.2 % to 52.2 %. The films could maintain a high tensile strength of 340 MPa, and result in a CO2 absorption rate of 3.5 mmol/gcellulose after 30 days. In this study, the improvement of durability and carbon sequestration of nanocellulose films was achieved by a simple and effective method.

Aerogels based on Bacterial Nanocellulose and their Applications

Microbial cellulose stands out for its exceptional characteristics in the form of biofilms formed by highly interlocked fibrils, namely, bacterial nanocellulose (BNC). Concurrently, bio-based aerogels are finding uses in innovative materials owing to their lightweight, high surface area, physical, mechanical, and thermal properties. In particular, bio-based aerogels based on BNC offer significant opportunities as alternatives to synthetic or mineral counterparts. BNC aerogels are proposed for diverse applications, ranging from sensors to medical devices, as well as thermal and electroactive systems. Due to the fibrous nanostructure of BNC and the micro-porosity of BNC aerogels, these materials enable the creation of tailored and specialized designs. Herein, a comprehensive review of BNC-based aerogels, their attributes, hierarchical, and multiscale features are provided. Their potential across various disciplines is highlighted, emphasizing their biocompatibility and suitability for physical and chemical modification. BNC aerogels are shown as feasible options to advance material science and foster sustainable solutions through biotechnology.

Carbon Dioxide Capture by Emerging Innovative Polymers: Status and Perspectives

A significant amount of research has been conducted in carbon dioxide (CO2) capture, particularly over the past decade, and continues to evolve. This review presents the most recent advancements in synthetic methodologies and CO2 capture capabilities of diverse polymer-based substances, which includes the amine-based polymers, porous organic polymers, and polymeric membranes, covering publications in the last 5 years (2019-2024). It aims to assist researchers with new insights and approaches to develop innovative polymer-based materials with improved capturing CO2 capacity, efficiency, sustainability, and cost-effective, thereby addressing the current obstacles in carbon capture and storage to sooner meeting the net-zero CO2 emission target.

Catalytic and biomedical applications of nanocelluloses: A review of recent developments

Nanocelluloses exhibit immense potential in catalytic and biomedical applications. Their unique properties, biocompatibility, and versatility make them valuable in various industries, contributing to advancements in environmental sustainability, catalysis, energy conversion, drug delivery, tissue engineering, biosensing/imaging, and wound healing/dressings. Nanocellulose-based catalysts can efficiently remove pollutants from contaminated environments, contributing to sustainable and cleaner ecosystems. These materials can also be utilized as drug carriers, enabling targeted and controlled drug release. Their high surface area allows for efficient loading of therapeutic agents, while their biodegradability ensures safer and gradual release within the body. These targeted drug delivery systems enhance the efficacy of treatments and minimizes side effects. Moreover, nanocelluloses can serve as scaffolds in tissue engineering due to their structural integrity and biocompatibility. They provide a three-dimensional framework for cell growth and tissue regeneration, promoting the development of functional and biologically relevant tissues. Nanocellulose-based dressings have shown great promise in wound healing and dressings. Their ability to absorb exudates, maintain a moist environment, and promote cell proliferation and migration accelerates the wound healing process. Herein, the recent advancements pertaining to the catalytic and biomedical applications of nanocelluloses and their composites are deliberated, focusing on important challenges, advantages, limitations, and future prospects.

Nanocellulose-stabilized nanocomposites for effective Hg(II) removal and detection: a comprehensive review

Mercury pollution, with India ranked as the world's second-largest emitter, poses a critical environmental and public health challenge and underscores the need for rigorous research and effective mitigation strategies. Nanocellulose is derived from cellulose, the most abundant natural polymer on earth, and stands out as an excellent choice for mercury ion remediation due to its remarkable adsorption capacity, which is attributed to its high specific surface area and abundant functional groups, enabling efficient Hg(II) ion removal from contaminated water sources. This review paper investigates the compelling potential of nanocellulose as a scavenging tool for Hg(II) ion contamination. The comprehensive examination encompasses the fundamental attributes of nanocellulose, its diverse fabrication techniques, and the innovative development methods of nanocellulose-based nanocomposites. The paper further delves into the mechanisms that underlie Hg removal using nanocellulose, as well as the integration of nanocellulose in Hg detection methodologies, and also acknowledges the substantial challenges that lie ahead. This review aims to pave the way for sustainable solutions in mitigating Hg contamination using nanocellulose-based nanocomposites to address the global context of this environmental concern.

Biopolymeric Nanocomposites for CO2 Capture

Carbon dioxide (CO2) impacts the greenhouse effect significantly and results in global warming, prompting urgent attention to climate change concerns. In response, CO2 capture has emerged as a crucial process to capture carbon produced in industrial and power processes before its release into the atmosphere. The main aim of CO2 capture is to mitigate the emissions of greenhouse gas and reduce the anthropogenic impact on climate change. Biopolymer nanocomposites offer a promising avenue for CO2 capture due to their renewable nature. These composites consist of biopolymers derived from biological sources and nanofillers like nanoparticles and nanotubes, enhancing the properties of the composite. Various biopolymers like chitosan, cellulose, carrageenan, and others, possessing unique functional groups, can interact with CO2 molecules. Nanofillers are incorporated to improve mechanical, thermal, and sorption properties, with materials such as graphene, carbon nanotubes, and metallic nanoparticles enhancing surface area and porosity. The CO2 capture mechanism within biopolymer nanocomposites involves physical absorption, chemisorption, and physisorption, driven by functional groups like amino and hydroxyl groups in the biopolymer matrix. The integration of nanofillers further boosts CO2 adsorption capacity by increasing surface area and porosity. Numerous advanced materials, including biopolymeric derivatives like cellulose, alginate, and chitosan, are developed for CO2 capture technology, offering accessibility and cost-effectiveness. This semi-systematic literature review focuses on recent studies involving biopolymer-based materials for CO2 capture, providing an overview of composite materials enriched with nanomaterials, specifically based on cellulose, alginate, chitosan, and carrageenan; the choice of these biopolymers is dictated by the lack of a literature perspective focused on a currently relevant topic such as these biorenewable resources in the framework of carbon capture. The production and efficacy of biopolymer-based adsorbents and membranes are examined, shedding light on potential trends in global CO2 capture technology enhancement.

Advances in Polysaccharides for Cartilage Tissue Engineering Repair: A Review

Cartilage repair has been a significant challenge in orthopedics that has not yet been fully resolved. Due to the absence of blood vessels and the almost cell-free nature of mature cartilage tissue, the limited ability to repair cartilage has resulted in significant socioeconomic pressures. Polysaccharide materials have recently been widely used for cartilage tissue repair due to their excellent cell loading, biocompatibility, and chemical modifiability. They also provide a suitable microenvironment for cartilage repair and regeneration. In this Review, we summarize the techniques used clinically for cartilage repair, focusing on polysaccharides, polysaccharides for cartilage repair, and the differences between these and other materials. In addition, we summarize the techniques of tissue engineering strategies for cartilage repair and provide an outlook on developing next-generation cartilage repair and regeneration materials from polysaccharides. This Review will provide theoretical guidance for developing polysaccharide-based cartilage repair and regeneration materials with clinical applications for cartilage tissue repair and regeneration.

The emergence of nanocellulose aerogels in CO2 adsorption

Mitigating the effect of climate change toward a sustainable development is one of the main challenges of our century. The emission of greenhouse gases, especially carbon dioxide (CO2), is a leading cause of the global warming crisis. To address this issue, various sustainable strategies have been formulated for CO2 capture. Renewable nanocellulose aerogels have risen as a highly attractive candidate for CO2 capture thanks to their porous and surface-tunable nature. Nanocellulose offer distinctive characteristics, including significant aspect ratios, exceptional biodegradability, lightweight nature, and the ability for chemical modification due to the abundant presence of hydroxyl groups. In this review, recent research studies on nanocellulose-based aerogels designed for CO2 absorption have been highlighted. The state-of-the-art of nanocellulose-based aerogel has been thoroughly assessed, including their synthesis, drying methods, and characterization techniques. Additionally, discussions were held about the mechanisms of CO2 adsorption, the effects of the porous structure, surface functionalization, and experimental parameters. Ultimately, this synthesis review provides an overview of the achieved adsorption rates using nanocellulose-based aerogels and outlines potential improvements that could lead to optimal adsorption rates. Overall, this research holds significant promise for tackling the challenges of climate change and contributing to a more sustainable future.

Incorporation of Cellulose-Based Aerogels into Textile Structures

Given their exceptional attributes, aerogels are viewed as a material with immense potential. Being a natural polymer, cellulose offers the advantage of being both replenishable and capable of breaking down naturally. Cellulose-derived aerogels encompass the replenish ability, biocompatible nature, and ability to degrade naturally inherent in cellulose, along with additional benefits like minimal weight, extensive porosity, and expansive specific surface area. Even with increasing appreciation and acceptance, the undiscovered possibilities of aerogels within the textiles sphere continue to be predominantly uninvestigated. In this context, we outline the latest advancements in the study of cellulose aerogels' formulation and their diverse impacts on textile formations. Drawing from the latest studies, we reviewed the materials used for the creation of various kinds of cellulose-focused aerogels and their properties, analytical techniques, and multiple functionalities in relation to textiles. This comprehensive analysis extensively covers the diverse strategies employed to enhance the multifunctionality of cellulose-based aerogels in the textiles industry. Additionally, we focused on the global market size of bio-derivative aerogels, companies in the industry producing goods, and prospects moving forward.

The emergence of hybrid cellulose nanomaterials as promising biomaterials

Cellulose nanomaterials (CNs) are promising green materials due to their unique properties as well as their environmental benefits. Among these materials, cellulose nanofibrils (CNFs) and nanocrystals (CNCs) are the most extensively researched types of CNs. While they share some fundamental properties like low density, biodegradability, biocompatibility, and low toxicity, they also possess unique differentiating characteristics such as morphology, rheology, aspect ratio, crystallinity, mechanical and optical properties. Therefore, numerous comparative studies have been conducted, and recently, various studies have reported the synergetic advantages resulting from combining CNF and CNC. In this review, we initiate by addressing the terminology used to describe combinations of these and other types of CNs, proposing "hybrid cellulose nanomaterials" (HCNs) as the standardized classifictation for these materials. Subsequently, we briefly cover aspects of properties-driven applications and the performance of CNs, from both an individual and comparative perspective. Next, we comprehensively examine the potential of HCN-based materials, highlighting their performance for various applications. In conclusion, HCNs have demonstraded remarkable success in diverse areas, such as food packaging, electronic devices, 3D printing, biomedical and other fields, resulting in materials with superior performance when compared to neat CNF or CNC. Therefore, HCNs exhibit great potential for the development of environmentally friendly materials with enhanced properties.

Current and Potential Applications of Green Membranes with Nanocellulose

Large-scale applications of nanotechnology have been extensively studied within the last decade. By exploiting certain advantageous properties of nanomaterials, multifunctional products can be manufactured that can contribute to the improvement of everyday life. In recent years, one such material has been nanocellulose. Nanocellulose (NC) is a naturally occurring nanomaterial and a high-performance additive extracted from plant fibers. This sustainable material is characterized by a unique combination of exceptional properties, including high tensile strength, biocompatibility, and electrical conductivity. In recent studies, these unique properties of nanocellulose have been analyzed and applied to processes related to membrane technology. This article provides a review of recent synthesis methods and characterization of nanocellulose-based membranes, followed by a study of their applications on a larger scale. The article reviews successful case studies of the incorporation of nanocellulose in different types of membrane materials, as well as their utilization in water purification, desalination, gas separations/gas barriers, and antimicrobial applications, in an effort to provide an enhanced comprehension of their capabilities in commercial products.

Cellulose acylation in homogeneous and heterogeneous media: Optimization of reactions conditions

The dependence of the DS on the acid anhydride/anhydroglucose unit ((RCO)₂O/AGU) molar ratio was correlated using second-order polynomials. The regression coefficients of the (RCO)₂O/AGU terms showed that increasing the length of the RCO group of the anhydride led to lower values of DS. For acylation under heterogeneous reaction conditions, the following were employed: acid anhydrides and butyryl chloride as acylating agents; iodine as a catalyst; N,N-dimethylformamide (DMF) as a solvent, pyridine, and triethylamine as solvents and catalysts. For acylation using acetic anhydride plus iodine, the values of DS correlate with reaction time by a second-order polynomial. Due to its role as a polar solvent and a nucleophilic catalyst, pyridine was the most effective base catalyst, independent of the acylating agent (butyric anhydride and butyryl chloride).

Challenges associated with cellulose composite material: Facet engineering and prospective

Cellulose is the most abundant polysaccharide on earth. It has a large number of desirable properties. Its low toxicity makes it more useful for a variety of applications. Nowadays, its composites are used in most engineering fields. Composite consists of a polymer matrix and use as a reinforcing material. By reducing the cost of traditional fibers, it has an increasing demand for environment-friendly purposes. The use of these types of composites is inherent in moisture absorption with hindered natural fibers. This determines the reduction of polymer composite material. By appropriate chemical surface treatment of cellulose composite materials, the effect could be diminished. The most modern and advanced techniques and methods for the preparation of cellulose and polymer composites are discussed here. Cellulosic composites show a reinforcing effect on the polymer matrix as pointed out by mechanical characterization. Researchers tried their hard work to study different ways of converting various agricultural by-products into useful eco-friendly polymer composites for sustainable production. Cellulose plays building blocks, that are critical for polymer products and their engineering applications. The most common method used to prepare composites is in-situ polymerization. This help to increase the yields of cellulosic composites with a significant enhancement in thermal stability and mechanical properties. Recently, cellulose composites used as enhancing the incorporation of inorganic materials in multi-functional properties. Furthermore, we have summarized in this review the potential applications of cellulose composites in different fields like packaging, aerogels, hydrogels, and fibers.

Antimicrobial Nano-Zinc Oxide Biocomposites for Wound Healing Applications: A Review

Chronic wounds are a major concern for global health, affecting millions of individuals worldwide. As their occurrence is correlated with age and age-related comorbidities, their incidence in the population is set to increase in the forthcoming years. This burden is further worsened by the rise of antimicrobial resistance (AMR), which causes wound infections that are increasingly hard to treat with current antibiotics. Antimicrobial bionanocomposites are an emerging class of materials that combine the biocompatibility and tissue-mimicking properties of biomacromolecules with the antimicrobial activity of metal or metal oxide nanoparticles. Among these nanostructured agents, zinc oxide (ZnO) is one of the most promising for its microbicidal effects and its anti-inflammatory properties, and as a source of essential zinc ions. This review analyses the most recent developments in the field of nano-ZnO–bionanocomposite (nZnO-BNC) materials—mainly in the form of films, but also hydrogel or electrospun bandages—from the different preparation techniques to their properties and antibacterial and wound-healing performances. The effect of nanostructured ZnO on the mechanical, water and gas barrier, swelling, optical, thermal, water affinity, and drug-release properties are examined and linked to the preparation methods. Antimicrobial assays over a wide range of bacterial strains are extensively surveyed, and wound-healing studies are finally considered to provide a comprehensive assessment framework. While early results are promising, a systematic and standardised testing procedure for the comparison of antibacterial properties is still lacking, partly because of a not-yet fully understood antimicrobial mechanism. This work, therefore, allowed, on one hand, the determination of the best strategies for the design, engineering, and application of n-ZnO-BNC, and, on the other hand, the identification of the current challenges and opportunities for future research.

Application of cellulose- and chitosan-based edible coatings for quality and safety of deep-fried foods

Excessive oil uptake and formation of carcinogens, such as acrylamide (AA), heterocyclic amines (HCAs), and polycyclic aromatic hydrocarbons (PAHs), during deep-frying are a potential threat for food quality and safety. Cellulose- and chitosan-based edible coatings have been widely applied to deep-fried foods for reduction of oil uptake because of their barrier property to limit oil ingress, and their apparent inhibition of AA formation. Cellulose- and chitosan-based edible coatings have low negative impacts on sensory attributes of fried foods and are low cost, nontoxic, and nonallergenic. They also show great potential for reducing HCAs and PAHs in fried foods. The incorporation of nanoparticles improves mechanical and barrier properties of cellulose and chitosan coatings, which may also contribute to reducing carcinogens derived from deep-frying. Considering the potential for positive health outcomes, cellulose- and chitosan-based edible coatings could be a valuable method for the food industry to improve the quality and safety of deep-fried foods.

Coagulation/flocculation-flotation harvest of Microcystis aeruginosa by cationic hydroxyethyl cellulose and Agrobacterium mucopolysaccharides

Efficient biocoagulants/bioflocculants are desired for removal of Microcystis aeruginosa, the dominant harmful bloom-forming cyanobacterium. Herein, we reported cationic hydroxyethyl cellulose (CHEC) inactivated M. aeruginosa cells after forming coagulates and floating-flocculated them with aid of Agrobacterium mucopolysaccharides (AMP) and surfactant. CHEC exhibited cyanocidal activity at 20 mg/L, coagulating 85% of M. aeruginosa biomass within 9 h and decreasing 41% of chlorophyll a after 72 h. AMP acted as an adhesive flocculation aid that accelerated and strengthened the formation of flocs, approaching a maximum in 10 min. Flocs of M. aeruginosa were floated after foaming with cocoamidopropyl betaine (CAB), which facilitated the subsequent filter harvest. 82% of M. aeruginosa biomass was suspended on water surface after treated with the coagulation/flocculation-flotation (CFF) agents containing CHEC (25 mg/L), AMP (177 mg/L) and CAB (0.1 mg/L). All components in CFF agents at the applied concentrations did not inhibit acetylcholinesterase or Vibrio fischeri. Our findings provide new insights in developing bio-based materials for sustainable control of cyanobacterial blooms.

Azadirachta indica leaf extract mediated silver nanoparticles impregnated nano composite film (AgNP/MCC/starch/whey protein) for food packaging applications

In order to be used in food packaging, the study aims to develop a composite film based on microcrystalline cellulose (MCC) and coated with silver nanoparticles (AgNPs). The MCC was derived from sugar cane bagasse. Protein, starch, and poly-ethylene glycol 1500 (PEG-1500) are employed to improve the tensile strength, flexibility, and durability of the packaging film. The AgNPs was synthesized by a green route employing Azadirachtaindica leaf extract as reducing agent. The determined average crystallite size of AgNPs was seen at 20 nm. The X-ray diffraction (XRD) studies of the final film prepared have an elevated peak with a crystallinity of 37.5%. The scanning electron microscopic images (SEM) of the AgNPs and the prepared samples, reveal their surface morphology. The Fourier transform infrared spectroscopic studies (FT-IR) disclose the functional group changes during the film preparation. The antibacterial activity of the amalgamated AgNPs against five bacterial pathogens studied was found to be highly active against tested food pathogens, except for Proteus vulgari. When coated over a vegetable, the produced nanocomposite film displayed an increased shelf life for the vegetable by limiting the decay impact caused by food pathogens. According to the findings, the AgNPs-impregnated MCC/Starch/Whey protein has the potential to be employed as an antimicrobial packaging material.

Preparation of Chemically Resistant Cellulose Benzoate Hollow Fiber Membrane via Thermally Induced Phase Separation Method

For the first time, we have successfully fabricated microfiltration (MF) hollow fiber membranes by the thermally induced phase separation (TIPS) and non-solvent induced phase separation (NIPS) methods using cellulose acetate benzoate (CBzOH), which is a cellulose derivative with considerable chemical resistance. To obtain an appropriate CBzOH TIPS membrane, a comprehensive solvent screening was performed to choose the appropriate solvent to obtain a membrane with a porous structure. In parallel, the CBzOH membrane was prepared by the NIPS method to compare and evaluate the effect of membrane structure using the same polymer material. Prepared CBzOH membrane by TIPS method showed high porosity, pore size around 100 nm or larger and high pure water permeability (PWP) with slightly low rection performance compared to that by NIPS. On the contrary, CBzOH membranes prepared with the NIPS method showed three times lower PWP with higher rejection. The chemical resistance of the prepared CBzOH membranes was compared with that of cellulose triacetate (CTA) hollow fiber membrane, which is a typical cellulose derivative as a control membrane, using a 2000 ppm sodium hypochlorite (NaClO) solution. CBzOH membranes prepared with TIPS and NIPS methods showed considerable resistance against the NaClO solution regardless of the membrane structure, porosity and pore size. On the other hand, when the CTA membrane, as the control membrane, was subjected to the NaClO solution, membrane mechanical strength sharply decreased over the exposure time to NaClO. It is interesting that although the CBzOH TIPS membrane showed three times higher pure water permeability than other membranes with slightly lower rejection and considerably higher NaClO resistance, the mechanical strength of this membrane is more than two times higher than other membranes. While CBzOH samples showed no change in chemical structure and contact angle, CTA showed considerable change in chemical structure and a sharp decrease in contact angle after treatment with NaClO. Thus, CBzOH TIPS hollow fiber membrane is noticeably interesting considering membrane performance in terms of filtration performance, mechanical strength and chemical resistance on the cost of slightly losing rejection performance.

Preparation of Microfiltration Hollow Fiber Membranes from Cellulose Triacetate by Thermally Induced Phase Separation

For the first time, self-standing microfiltration (MF) hollow fiber membranes were prepared from cellulose triacetate (CTA) via the thermally induced phase separation (TIPS) method. The resultant membranes were compared with counterparts prepared from cellulose diacetate (CDA) and cellulose acetate propionate (CAP). Extensive solvent screening by considering the Hansen solubility parameters of the polymer and solvent, the polymer's solubility at high temperature, solidification of the polymer solution at low temperature, viscosity, and processability of the polymeric solution, is the most challenging issue for cellulose membrane preparation. Different phase separation mechanisms were identified for CTA, CDA, and CAP polymer solutions prepared using the screened solvents for membrane preparation. CTA solutions in binary organic solvents possessed the appropriate properties for membrane preparation via liquid-liquid phase separation, followed by a solid-liquid phase separation (polymer crystallization) mechanism. For the prepared CTA hollow fiber membranes, the maximum stress was 3-5 times higher than those of the CDA and CAP membranes. The temperature gap between the cloud point and crystallization onset in the polymer solution plays a crucial role in membrane formation. All of the CTA, CDA, and CAP membranes had a very porous bulk structure with a pore size of ∼100 nm or larger, as well as pores several hundred nanometers in size at the inner surface. Using an air gap distance of 0 mm, the appropriate organic solvents mixed in an optimized ratio, and a solvent for cellulose derivatives as the quench bath media, it was possible to obtain a CTA MF hollow fiber membrane with high pure water permeance and notably high rejection of 100 nm silica nanoparticles. It is expected that these membranes can play a great role in pharmaceutical separation.

A state-of-the-art review of CO2 enhanced oil recovery as a promising technology to achieve carbon neutrality in China

Although there are some review papers on carbon capture, utilization and storage (CCUS), hardly any of these reviews are focused on the role of CO₂ enhanced oil recovery (EOR) in accelerating carbon neutrality in China. In this review, strategies to achieve carbon neutrality is briefly but critically discussed, followed by a review of CO₂-EOR as a promising technology. Especially, data analysis, including the number of publications on China's carbon neutrality, per capita CO₂ emissions, China's power generation, and the crude oil production of China's large oilfields, is carried out to make the discussion more comprehensive. Given the large amount of coal consumed in China, the high percent of electricity generated with coal, and the slow penetration of renewables already observed, it seems unlikely that 2060 targets will be met without CCUS. In order to achieve carbon neutrality, both reduction in carbon emissions and increase in carbon sequestration are inevitable. Furthermore, it is concluded that CO₂ storage through EOR is likely to have a bright future. However, there are some critical issues to be solved, including the technical issues, leakage and safety issues, cost issues, policy issues, etc. In order to turn CO₂-EOR into a reliable and more favorable technology, more research and efforts are needed to solve these issues, including advancing carbon capture technologies, improving storage technologies, developing effective monitoring technologies, deploying government support and incentive policies, etc.

Recent Development and Environmental Applications of Nanocellulose-Based Membranes

Extensive research and development in the production of nanocellulose production, a green, bio-based, and renewable biomaterial has paved the way for the development of advanced functional materials for a multitude of applications. From a membrane technology perspective, the exceptional mechanical strength, high crystallinity, tunable surface chemistry, and anti-fouling behavior of nanocellulose, manifested from its structural and nanodimensional properties are particularly attractive. Thus, an opportunity has emerged to exploit these features to develop nanocellulose-based membranes for environmental applications. This review provides insights into the prospect of nanocellulose as a matrix or as an additive to enhance membrane performance in water filtration, environmental remediation, and the development of pollutant sensors and energy devices, focusing on the most recent progress from 2017 to 2022. A brief overview of the strategies to tailor the nanocellulose surface chemistry for the effective removal of specific pollutants and nanocellulose-based membrane fabrication approaches are also presented. The major challenges and future directions associated with the environmental applications of nanocellulose-based membranes are put into perspective, with primary emphasis on advanced multifunctional membranes.

Fluorescence response mechanism of green synthetic carboxymethyl chitosan-Eu3+ aerogel to acidic gases

Industrial waste acidic gases are huge hazards to the environment and human health, so a material that can detect and remove them is needed. In this paper, CM chitosan-Eu³⁺ fluorescence aerogel was prepared via a green method by combining the carboxymethyl chitosan biomass polymer with Eu³⁺ ions, the structure and properties of this aerogel were characterized by SEM, TG, and stress-strain curves. The coordination of Eu³⁺ ions and carboxymethyl chitosan was analyzed with XPS and the difference in luminescence intensity of aerogel prepared at different pH values was analyzed. The monitoring of the aerogels revealed different responses to different acidic gases, and the fluorescence intensity of the aerogel showed a linear decrease with the adsorbed hydrogen chloride gas (HCl), while acetic acid gas (HAc) enhanced fluorescence. The adsorption system of the CM chitosan-Eu³⁺ aerogel was simulated using pseudo-second-order kinetics, which showed that the maximum adsorption capacity of HCl is 9.16 mmol/g. The different response mechanisms of HCl and HAc gas were analyzed with FT-IR, fluorescence lifetime imaging and Judd-Ofelt theory. This fluorescence aerogel was found to have potential applications in ensuring industrial production safety.

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.

Nanocellulose Length Determines the Differential Cytotoxic Effects and Inflammatory Responses in Macrophages and Hepatocytes

Nanocellulose including cellulose nanocrystal (CNC) and cellulose nanofiber (CNF) has attracted much attention due to its exceptional mechanical, chemical, and rheological properties. Although considered biocompatible, recent reports have demonstrated nanocellulose can be hazardous, including serving as drug carriers that accumulate in the liver. However, the nanocellulose effects on liver cells, including Kupffer cells (KCs) and hepatocytes are unclear. Here, the toxicity of nanocellulose with different lengths is compared, including the shorter CNCs (CNC-1, CNC-2, and CNC-3) and longer CNF (CNF-1 and CNF-2), to liver cells. While all CNCs triggered significant cytotoxicity in KCs and only CNC-2 induced toxicity to hepatocytes, CNFs failed to induce significant cytotoxicity due to their minimal cellular uptake. The phagocytosis of CNCs by KCs induced mitochondria ROS generation, caspase-3/7 activation, and apoptotic cell death as well as lysosomal damage, cathepsin B release, NLRP3 inflammasome and caspase-1 activation, and IL-1β production. The cellular uptake of CNC-2 by hepatocytes is through clathrin-mediated endocytosis, and it induced the caspase-3/7-mediated apoptosis. CNC-2 shows the highest levels of uptake and cytotoxicity among CNCs. These results demonstrate the length-dependent mechanisms of toxicity on liver cells in a cell type-dependent fashion, providing information to safely use nanocellulose for biomedical applications.