Search Results (86)

The enzyme ω-transaminase (ω-TA) has garnered significant attention due to its capacity to catalyze the synthesis of chiral amines with high efficiency. Nevertheless, the lack of stability of ω-TA and the difficulty of recycling and reuse are still challenges that limit its application. This study developed a novel magnetic nanocellulose composite carrier (NNC@Fe₃O₄@Ni), synthesized from microcrystalline cellulose via low-eutectic solvent treatment, amine modification, and metal hybridization. The NNC@Fe₃O₄@Ni was characterized by FTIR, XPS, XRD, BET, and VSM. Additionally, the performance and catalytic behavior of the immobilized enzyme were investigated. The results revealed that NNC@Fe₃O₄@Ni exhibited a high specific surface area, superparamagnetism, and dual-site functionality (amine/Ni²⁺). Response Surface Methodology (RSM) optimized the carrier-enzyme interaction parameters, yielding optimal immobilization conditions: a mass ratio of 50.8 mg g⁻¹, temperature of 12.5 °C, and duration of 58.6 min, achieving 82.91% enzyme activity recovery. Compared to free enzymes, the immobilized variant demonstrated enhanced catalytic stability, with expanded optimal pH (9.0) and temperature (30 °C). Thermal stability assessments showed 84.39% activity retention after 5 h at 30 °C and 90.30% residual activity post-120 h storage. The catalyst maintained >80% efficiency over 10 reuse cycles. These findings confirm the efficacy of magnetic nanocellulose carriers in enhancing ω-TA stability, reusability, and catalytic performance, offering a viable strategy for industrial biocatalytic processes. Full article

The design of functional paper coatings with excellent barrier properties, including water repellence, anti-microbial properties, and recyclability, is highly demanded in view of the sustainable use of paper as flexible substrates for various industrial applications such as packaging. The enhanced coating functionalities should be incorporated through a combination of selected bio-based materials and the creation of appropriate surface textures enhancing coating performance. The bio-inspired approaches through the replication of hierarchical surface structures with multi-scale dimensional features in combination with selection of appropriate bio-based functional groups offer new concepts for coating design. In this short perspective paper, concepts in the field are illustrated with a focus on the combination of hydrophobic and anti-microbial properties. Based on long-term work with the available toolbox of bio-based building blocks and nanoscale architectures, they can be processed into applicable aqueous suspensions for sprayable paper coatings. The macroscopic roughness profile of paper substrates can be complemented through the decoration of nanoscale bio-based polymer particles of polyhydroxybutyrate or vegetable oil capsules with dimensions in the range of 20–50 nm or 100–500 nm depending on the synthesis conditions. The anti-microbial properties can be provided by the surface modification of nanocellulose with biologically active molecules sourced from nature. Besides the more fundamental issues in design and synthesis, the industrial application of the bio-inspired coatings through spray-coating becomes relevant. Full article

Nanocellulose, including cellulose nanofibers (CNFs), cellulose nanocrystals (CNCs), and bacterial nanocellulose (BNC), represents a promising class of bio-based nanomaterials derived from natural sources. These materials, derived from plant-based cellulose, are characterized by exceptional mechanical strength, high surface area, biodegradability, and the ability to form stable nanoparticle networks, making them suitable for use in composites, biomedicine, electronics, and many other fields. In this review, we present the latest advancements in the production of nanocellulose, including preparation technologies and methods for chemical and physical modifications to enhance the performance of these materials. We also discuss various applications, such as its use in nanocomposites, sustainable packaging materials, flexible electronic devices, and as a support for biological media. Additionally, the challenges and opportunities related to the scalability of production and their integration into industries with growing economic and ecological demands are explored. The review provides a comprehensive overview of the potential of nanocellulose, highlighting its importance in the context of emerging technologies and sustainability. Full article

Shale formations pose significant challenges to traditional drilling fluids, including issues such as fluid invasion, cutting dispersion, and shale swelling, contributing to wellbore instability. While oil-based drilling fluids (OBM) effectively address these challenges, concerns over their environmental impact and cost limit their widespread adoption. Nanoparticles (NPs) have emerged as a promising frontier for enhancing the performance of water-based drilling fluids (WBDFs) in shale applications. This study examines the effectiveness of water-based drilling fluids (WBDFs) enhanced with a nanocomposite of graphene oxide (GO) and nanocellulose (NC) compared to that of conventional WBDFs. The combination of GO and NC is chosen for its synergistic effects: GO provides enhanced mechanical strength and barrier properties, while NC serves to stabilize the dispersion and improve the compatibility with WBDF matrices. The modification with NC aims to optimize the interaction between GO and the drilling fluid components, enhancing performance in regards to shale inhibition and fluid loss control. This research involved the successful synthesis and characterization of a GO/NC nanocomposite, which underwent examination through FTIR, PSD, and SEM analyses. We also evaluated the filtration properties of water-based drilling fluids (WBDF) enhanced with a graphene oxide/nanocellulose (GO/NC) nanocomposite and compared the results to those for conventional WBDF. Filtration performance was assessed under both low-temperature, low-pressure (LTLP) and high-temperature, high-pressure (HTHP) conditions, and contact angle measurements were conducted to examine the wettability of the shale. The results demonstrated that incorporating GO/NC into the WBDF reduced the filtrate volume by 17% under LTLP conditions and by 23.75% under HTHP conditions, indicating a significant improvement in filtration control. Furthermore, the GO/NC-WBDF increased the hydrophobicity of the shale, as shown by a 61° increase in the contact angle. These findings suggest that GO/NC enhances the performance of WBDF, particularly in unconventional shale formations, by reducing fluid loss and improving wellbore stability. Full article

This study investigates the influence of nanocellulose fibre (CF) derived from wood pulp on the hydration, mechanical, shrinkage, and pore properties of ordinary Portland cement (OPC) mortar. The CF was incorporated into mortar mixes at varying dosages (0.15–1.5% by weight of mortar) to evaluate its effect on physical, mechanical, and microstructure properties. X-ray diffraction (XRD), thermogravimetric analysis (TGA/DTG), and mercury intrusion porosimetry (MIP) were employed to assess the hydration phases and microstructural changes induced by the CF addition. Experimental results indicate that CF alters the hydration kinetics of cement mortar by influencing the formation of hydration products such as calcium silicate hydrate (C-S-H), portlandite (CH), and carbonate phases. The introduction of CF enhances crack resistance and shrinkage control, particularly at an optimal dosage of 0.45%, which exhibited reduced drying shrinkage and improved phase stability. While CF incorporation had minimal impact on compressive and flexural strength at lower dosages (≤0.45%), higher CF contents (>0.99%) caused pore structure modifications, leading to an increase in total porosity and a reduction in strength. The XRD analysis revealed that CF does not introduce new hydration phases but modifies the crystallinity of existing phases. The hydration behaviour, as indicated by TGA/DTG, showed an increase in bound water content at moderate CF dosages, suggesting enhanced internal curing and prolonged hydration. Overall, the findings demonstrate that CF is a viable sustainable additive for cementitious materials, offering advantages in shrinkage control, hydration enhancement, and durability improvement. The results suggest that an optimal CF dosage of 0.45% provides a balance between workability, mechanical properties, and durability, making it an effective additive for enhancing the performance of OPC mortars in sustainable construction applications. Full article

Among the most promising areas of research, cellulose-based electrochemical sensors stand out for their intrinsic properties such as abundance, biocompatibility, and versatility. This review is concerned with the integration and application of cellulose-derived materials in electrochemical sensors, pointing out improvements in sensitivity, selectivity, stability, and functionality for a wide variety of applications. The most relevant developments on cellulose-based sensors have been concentrated on nanocellulose composite synthesis, advanced cellulose modification, and the successful embedding in wearable technologies, medical diagnostics, and environmental monitoring. Considering these, it is worth mentioning that significant challenges still need to be overcome regarding the scalability of production, selectivity improvement, and long-term stability under real operational conditions. Future research efforts will concern the union of cellulose-based sensors with the Internet of Things (IoT) and artificial intelligence (AI) toward wiser and more sustainable health and environmental solutions. Correspondingly, this work puts cellulose in the front line among the most perspective materials for enabling the development of eco-friendly and high-performance sensing technologies. Full article

Lipase from Pseudomonas fluorescens (PFL) and laccase from Trametes versicolor were co-immobilized onto nanocellulose (NC), using a layer-by-layer approach. Initially, PFL was adsorbed onto NC through ionic and hydrophobic interactions. To achieve higher PFL immobilization yield and activity, NC was functionalized with aldehyde groups through periodate oxidation (NCox) or glutaraldehyde activation (NC-GA). FTIR analysis confirmed these chemical modifications. Among the functionalized NCs, NCox showed the best capacity to retain higher amounts of PFL (maximum load: 20 mg/g), and this support was selected to proceed with the co-immobilization experiments. In this process, NCox-250-PFL (NCox activated with 250 µmol/g of aldehyde groups) was covered with polyethyleneimine (PEI), laccase was co-immobilized, and a crosslinking step using glutaraldehyde was used to covalently attach the enzymes to the support, producing the biocatalyst NCox-250-PFL-PEI-Lac-GA. Co-immobilized enzymes presented higher thermal stability (50 °C) than soluble enzymes; co-immobilized laccase retained 61.1% of its activity after 24 h, and PFL retained about 90% after 48 h of deactivation at 50 °C. In operational stability assays, the heterogeneous biocatalysts maintained more than 45% of their activity after five cycles of pNPB hydrolysis and ABTS oxidation. This co-immobilized biocatalyst, with its high stability and activity retention, is a promising multi-active heterogeneous biocatalyst for use in cascade reactions of industrial interest. Full article

This study evaluated the stability and reusability of amino-functionalized nanocellulose aerogels as CO₂-adsorbent materials. The modified aerogels, synthesized via a controlled silylation using N-[3-(trimethoxysilyl) propyl] ethylenediamine (DAMO), demonstrated excellent thermal stability up to 250 °C (TGA) and efficient CO₂ adsorption through chemisorption, which was the main adsorption mechanism. The performance of the aerogels was assessed using both adsorption isotherms and the decay pressure technique, revealing that CO₂ adsorption capacity increased with higher amino group loading (4.62, 9.24, and 13.87 mmol of DAMO). At 298 K and 4 bar, CO₂ adsorption capacity increased proportionally with the amino group concentration, reaching values of 3.17, 5.98, and 7.86 mmol of CO₂ g⁻¹ polymer, respectively. Furthermore, over 20 adsorption/desorption cycles, the aerogels maintained 95% CO₂ desorption at ambient temperature, indicating their potential for industrial use. These findings highlight the aerogels suitability as stable, reusable materials for large scale CO₂ capture and storage technologies. Full article

Starch films have attracted increasing attention due to their biodegradability, edibility, and potential use as animal feed from post-products. Applications of starch-based films include food packaging, coating, and medicine capsules. However, a major drawback of starch-based films is their brittleness, particularly under dry conditions, caused by starch retrogradation and the instability of plasticizers. To address this challenge, various strategies and methodologies have been developed, including plasticization, chemical modification, and physical reinforcement. This review covers fundamental aspects, such as the microstructures, phase transitions, and compatibility of starch, as well as application-oriented techniques, including processing methods, plasticizer selection, and chemical modifications. Plasticizers play a crucial role in developing starch-based materials, as they mitigate brittleness and improve processability. Given the abundance of hydroxyl groups in starch, the plasticizers used must also contain hydroxyl or polar groups for compatibility. Chemical modification, such as esterification and etherification, effectively prevents starch recrystallization. Reinforcements, particularly with nanocellulose, significantly improved the mechanical properties of starch film. Drawing upon both the literature and our expertise, this review not only summarizes the advancements in this field but also identifies the limitations of current technologies and outlines promising research directions for future development. Full article

This research investigated the selected properties of nanocellulose films intended to serve as protective patches on fissured surfaces of wooden artefacts. The effects of their plasticisation with glycerol and functionalisation with selected silanes ((3-Glycidyloxypropyl)trimethoxysilane, and Methyltrimethoxysilane) were also determined. The obtained pure cellulose nanopapers (CNPs) had a homogeneous and compact structure but were very brittle, stiff, and wavy. Functionalisation with silanes made their structure more packed and reduced their equilibrium moisture content by 87–96%, depending on the type and concentration of the silane. Silane functionalisation also slightly improved nanopapers’ resistance to moulds. Plasticisation with glycerol provided CNPs with higher flexibility and resistance to fracture and made them flatter and smoother, reducing the wettability of their surfaces but increasing their hygroscopicity (EMC values increased 1.7–3.5 times for pure CNPs and 5–33 times for functionalised CNPs) and vulnerability to mould infestation. All prepared nanopapers can be easily glued to the wood surface and colour-matched using a nitro wood stain, oil paint or waterborne acrylic paint. The research showed that cellulose nanopapers modified with silanes and plasticised with glycerol seem to be a promising solution for protecting the cracked surface of wooden artefacts against further degradation due to external conditions. Full article

In this work, nanocellulose aqueous dispersions were studied as a bio-inspired consolidating agent for the recovery and conservation of ancient wood and compared with two of the most used traditional consolidants: the synthetic resins Paraloid B-72 and Regalrez 1126. The morphology of crystalline nanocellulose (CNC), determined using Scanning Electron Microscopy (SEM), presents with a rod-like shape, with a size ranging between 15 and 30 nm in width. Chemical characterization performed using the Fourier-Transform Infrared Spectroscopy (FT-IR) technique provides information on surface modifications, in this case, demonstrating the presence of only the characteristic peaks of nanocellulose. Moreover, conductometric, pH, and dry matter measurements were carried out, showing also in this case values perfectly conforming to what is found in the literature. The treated wood samples were observed under an optical microscope in reflected light and under a scanning electron microscope to determine, respectively, the damage caused by xylophages and the morphology of the treated surfaces. The images acquired show the greater similarity of the surfaces treated with nanocellulose to untreated wood, compared with other consolidating agents. Finally, a colorimetric analysis of these samples was also carried out before and after a first consolidation treatment, and after a second treatment carried out on the same samples three years later. The samples treated with CNC appeared very homogeneous and uniform, without alterations in their final color appearance, compared to other traditional synthetic products. Full article

Plant fibers’ wide availability and accessibility are the main causes of the growing interest in sustainable technologies. The two primary factors to consider while concentrating on composite materials are their low weight and highly specific features, as well as their environmental friendliness. Pineapple leaf fiber (PALF) stands out among natural fibers due to its rich cellulose content, cost-effectiveness, eco-friendliness, and good fiber strength. This review provides an intensive assessment of the surface treatment, extraction, characterization, modifications and progress, mechanical properties, and potential applications of PALF-based polymer composites. Classification of natural fibers, synthetic fibers, chemical composition, micro cellulose, nanocellulose, and cellulose-based polymer composite applications have been extensively reviewed and reported. Besides, the reviewed PALF can be extracted into natural fiber cellulose and lignin can be used as reinforcement for the development of polymer biocomposites with desirable properties. Furthermore, this review article is keen to study the biodegradation of natural fibers, lignocellulosic biopolymers, and biocomposites in soil and ocean environments. Through an evaluation of the existing literature, this review provides a detailed summary of PALF-based polymer composite material as suitable for various industrial applications, including energy generation, storage, conversion, and mulching films. Full article

Cellulose nanofibers (NF) were extracted from kapok fibers using TEMPO oxidation, followed by a combination of mechanical grinding and ultrasonic processing. The TEMPO-mediated oxidation significantly impacted the mechanical disintegration behavior of the kapok fibers, resulting in a high NF yield of 98%. This strategy not only improved the fibrillation efficiency but also reduced overall energy consumption during NF preparation. An ultralight and highly porous NF-based aerogel was successfully prepared using a simple ice-templating technique. It had a low density in the range of 3.5–11.2 mg cm⁻³, high compressional strength (160 kPa), and excellent thermal insulation performance (0.024 W m⁻¹ K⁻¹). After silane modification, the aerogel displayed an ultralow density of 7.9 mg cm⁻³, good hydrophobicity with a water contact angle of 128°, and excellent mechanical compressibility with a high recovery of 92% at 50% strain. Benefiting from the silene support structure, it showed a high oil absorptive capacity (up to 71.4 g/g for vacuum pump oil) and a remarkable oil recovery efficiency of 93% after being reused for 10 cycles. These results demonstrate that our strategy endows nanocellulose-based aerogels with rapid shape recovery and high liquid absorption capabilities. Full article

Nanocellulose is a nanostructured form of cellulose, which retains valuable properties of cellulose such as renewability, biodegradability, biocompatibility, nontoxicity, and sustainability and, due to its nano-sizes, acquires several useful features, such as low density, high aspect ratio and stiffness, a high specific surface area, easy processing and functionalisation, and good thermal stability. All these make it a highly versatile green nanomaterial for multiple applications, including the conservation of cultural heritage. This review provides the basic characteristics of all nanocellulose forms and their properties and presents the results of recent research on nanocellulose formulations applied for conserving historical artefacts made of wood and paper, discussing their effectiveness, advantages, and disadvantages. Pure nanocellulose proves particularly useful for conserving historical paper since it can form a durable, stable coating that consolidates the surface of a degraded object. However, it is not as effective for wood consolidation treatment due to its poor penetration into the wood structure. The research shows that this disadvantage can be overcome by various chemical modifications of the nanocellulose surface; owing to its specific chemistry, nanocellulose can be easily functionalised and, thus, enriched with the properties required for an effective wood consolidant. Moreover, combining nanocellulose with other agents can also improve its properties, adding new functionalities to the developed supramolecular systems that would address multiple needs of degraded artefacts. Since the broad use of nanocellulose in conservation practice depends on its properties, price, and availability, the development of new, effective, green, and industrial-scale production methods ensuring the manufacture of nanocellulose particles with standardised properties is necessary. Nanocellulose is an interesting and very promising solution for the conservation of cultural heritage artefacts made of paper and wood; however, further thorough interdisciplinary research is still necessary to devise new green methods of its production as well as develop new effective and sustainable nanocellulose-based conservation agents, which would replace synthetic, non-sustainable consolidants and enable proper conservation of historical objects of our cultural heritage. Full article

The research presented here is an attempt to develop an innovative and environmentally friendly material based on bacterial nanocellulose (BNC), which will be able to replace both animal skins and synthetic polymer products. Bacterial nanocellulose becomes stiff and brittle when dried, so attempts have been made to plasticise this material so that BNC can be used in industry. The research presented here focuses on the ecological modification of bacterial nanocellulose with vegetable oils such as rapeseed oil, linseed oil, and grape seed oil. The effect of compatibilisers of a natural origin on the plasticisation process of BNC, such as chlorophyll, curcumin, and L-glutamine, was also evaluated. BNC samples were modified with rapeseed, linseed, and grapeseed oils, as well as mixtures of each of these oils with the previously mentioned additives. The modification was carried out by passing the oil, or oil mixture, through the BNC using vacuum filtration, where the BNC acted as a filter. The following tests were performed to determine the effect of the modification on the BNC: FTIR spectroscopic analysis, contact angle measurements, and static mechanical analysis. As a result of the modification, the BNC was plasticised. Rapeseed oil proved to be the best for this purpose, with the help of which a material with good strength and elasticity was obtained. Full article