Enhanced hydrophobic paper-sheet derived from Miscanthus × giganteus cellulose fibers coated with esterified lignin and cellulose acetate blend

An in-situ dissolving-co-crosslinking strategy for fabricating high-strength, wet-stable, and biocompatible multiscale cellulosic paper-based plastics

Developing degradable plastics with excellent mechanical strength and wet stability from renewable and biodegradable biomass resources remains challenging. Here, we propose a simple one-step strategy for the in-situ multiscale dissolution of cellulose and crosslinking with 1,4-butanediol diglycidyl ether (BDDE) within a mixture of BDDE and AlCl3/ZnCl2 aqueous solution at room temperature. This strategy enables the synthesis of cellulosic paper-based bioplastics with high mechanical strength and wet stability from cellulose paper. In this process, conventional cellulose paper is partially dissolved, and simultaneously, BDDE forms chemical crosslinking with undissolved micro-level, nano-level cellulose fibers and dissolved cellulose macromolecules through an autocatalytic effect from AlCl3/ZnCl2 aqueous solution, resulting in multiscale physicochemical entanglements and multiple hydrogen bonds. Hence, the prepared bioplastic's dry and wet strength reached 58.2 MPa and 24.2 MPa, respectively, about 6.9 times and 71.2 times higher than untreated paper-based materials. The prepared bioplastic showed excellent wet stability, biosafety, and biodegradability. The density functional theory (DFT) simulation data indicates that Al3+, Zn2+ ions, and freely hydrated hydrogen protons are crucial to the dissolving-co-crosslinking system. This strategy involves only green and recyclable chemicals, offering a promising pathway for producing strong and biodegradable cellulosic paper-based bioplastics as an alternative to nondegradable plastics.

Study of factors affecting cellulose derivatives composite in anticancer drug delivery: A comprehensive review

The targeted distribution of therapeutic molecules in cancer cells poses several challenges for biomedical applications. Drug delivery systems (DDS) are primarily designed to target cancer cells effectively to achieve maximum therapeutic effects. Cellulose is a well-known organic molecule owing to its biodegradability, biocompatibility, low toxicity, prolonged stability, and superior loading characteristics. However, cellulose composites have faced numerous drawbacks, such as higher molecular size, non-covalent interactions, poor mechanical strength, and limited water solubility. In contrast, cellulose derivatization has enhanced drug loading and release efficiency, improved mechanical strength, and mitigated drug solubility issues. This review summarized the recent advancement in cellulose-based composites such as DDS for cancer cell treatment and discussed responsive factors. The pH, temperature, magnetic nanoparticles, solubility, porosity, mechanical strength, nanoparticle size, increased time of drug release, crosslinking efficiency, etc., are major responsive assays that influence the therapeutic potential of anticancer drugs. Furthermore, overviewed the cellulose nanoformulations in sustained anticancer drug release and successfully illustrated the synthesizing methodologies as well as challenges in efficient DDS applications. Moreover, a brief overview of the interdisciplinary industrial uses of cellulose composites, including paper, textiles, and nanotechnology, is presented. Finally, cellulose-based composites provide a novel way of producing excellent DDS with enhanced therapeutic properties.

Development of a new sustainable greener strategy for cellulose functionalization: A mechanochemical catalyst-free and solvent-free process in ambient conditions

The carboxylation of cellulose by maleic anhydride in the molten solvent-free and catalyst-free process gave a low degree of substitution (DS). The most of maleic anhydride was sublimated in its melting point and stirring became a problem. Therefore, the cellulose was functionalized with maleic anhydride for the first time by a planetary ball mill at ambient conditions in the absence of solvent and catalyst. The chemical structure, morphology and surface composition, particle size distribution, surface charge, and the degree of substitution of the functionalized cellulose were investigated. A reduction in particle size was demonstrated. The EDX analysis showed an increasing average C/O mass ratio. The zeta potential decreased from -10.2 mV for cellulose to -4.08 mV for functionalized cellulose. The DS was 3.10 ± 0.02, 3.23, and 3.24 mmol of carboxyl groups per gram of functionalized cellulose by the conductometry, back titration, and combined TG-DSC analysis, respectively. XPS C1s and O1s energies demonstrated cellulose functionalization. Moreover, TG-DTA plots demonstrated a slight decrease in the thermal stability of the functionalized cellulose. Water vaporization in a two-step process was observed for the functionalized cellulose. A glass transition and decarboxylation were detected in the DSC plot of the functionalized cellulose.

Hydrophobic Modification of Cellulose Acetate and Its Application in the Field of Water Treatment: A Review

With the inherent demand for hydrophobic materials in processes such as membrane distillation and unidirectional moisture conduction, the preparation and application development of profiles such as modified cellulose acetate membranes that have both hydrophobic functions and biological properties have become a research hotspot. Compared with the petrochemical polymer materials used in conventional hydrophobic membrane preparation, cellulose acetate, as the most important cellulose derivative, exhibits many advantages, such as a high natural abundance, good film forming, and easy modification and biodegradability, and it is a promising polymer raw material for environmental purification. This paper focuses on the research progress of the hydrophobic cellulose acetate preparation process and its current application in the water-treatment and resource-utilization fields. It provides a detailed introduction and comparison of the technical characteristics, existing problems, and development trends of micro- and nanostructure and chemical functional surface construction in the hydrophobic modification of cellulose acetate. Further review was conducted and elaborated on the applications of hydrophobic cellulose acetate membranes and other profiles in oil-water separation, brine desalination, water-repellent protective materials, and other separation/filtration fields. Based on the analysis of the technological and performance advantages of profile products such as hydrophobic cellulose acetate membranes, it is noted that key issues need to be addressed and urgently resolved for the further development of hydrophobic cellulose acetate membranes. This will provide a reference basis for the expansion and application of high-performance cellulose acetate membrane products in the environmental field.

Lignin: An Adaptable Biodegradable Polymer Used in Different Formulation Processes

INTRODUCTION

LIG is a biopolymer found in vascular plant cell walls that is created by networks of hydroxylated and methoxylated phenylpropane that are randomly crosslinked. Plant cell walls contain LIG, a biopolymer with significant potential for usage in modern industrial and pharmaceutical applications. It is a renewable raw resource. The plant is mechanically protected by this substance, which may increase its durability. Because it has antibacterial and antioxidant qualities, LIG also shields plants from biological and chemical challenges from the outside world. Researchers have done a great deal of work to create new materials and substances based on LIG. Numerous applications, including those involving antibacterial agents, antioxidant additives, UV protection agents, hydrogel-forming molecules, nanoparticles, and solid dosage forms, have been made with this biopolymer.

METHODS

For this review, a consistent literature screening using the Pubmed database from 2019-2024 has been performed.

RESULTS

The results showed that there is an increase in interest in lignin as an adaptable biomolecule. The most recent studies are focused on the biosynthesis and antimicrobial properties of lignin-derived molecules. Also, the use of lignin in conjunction with nanostructures is actively explored.

CONCLUSIONS

Overall, lignin is a versatile molecule with multiple uses in industry and medical science.

Hydrophobic, ultraviolet radiation-shielding, and antioxidant functionalities of TEMPO-oxidized cellulose nanofibril film coated with modified lignin nanoparticles

In this study, lignin nanoparticles (LN) and octadecylamine-modified LN (LN-ODA) were utilized as coating materials to enhance the hydrophobic, antioxidant, and ultraviolet radiation-shielding (UV-shielding) properties of a TEMPO-oxidized nanocellulose film (TOCNF). The water contact angle (WCA) of the TOCNF was approximately 53° and remained stable for 1 min, while the modified LN-ODA-coated TOCNF reached over 130° and maintained approximately 85° for an hour. Pure TOCNF exhibited low antioxidant properties (4.7 %), which were significantly enhanced in TOCNF-LN (81.6 %) and modified LN-ODA (10.3 % to 27.5 %). Modified LN-ODA-coated TOCNF exhibited antioxidant properties two to six times higher than those of pure TOCNF. Modified LN-ODA exhibited thermal degradation max (Tmax) at 421 °C, while pure LN showed the main degradation temperature at approximately Tmax 330 °C. The thermal stability of TOCNF-LN-ODA-coated materials remained consistent with that of pure TOCNF, while the crystallinity index of the sample showed a slight decrease due to the amorphous nature of the lignin structure. The tensile strength of TOCNF was approximately 114.1 MPa and decreased to 80.1, 51.3, and 30.3 MPa for LN-ODA coating at 5, 10, and 15 g/m2, respectively.

A simple approach to produce hydrophobic biobased coatings using methylcellulose and organosolv lignin

Substituting plastics with circular and sustainable alternatives has increasingly become a priority. Protective coatings, crucial components in numerous industries, are now in demand for biodegradable options to replace their plastic-based counterparts. Being one of nature's most abundant components, lignin remains underutilized, and this study focuses on investigating its potential for the production of biobased coatings. The method used here involved formulating coating suspensions by mixing methylcellulose and organosolv lignin powders and adding water to the mixture. Glass wafers were coated with the formulated suspensions using spin-coating. The morphology of the coated surfaces was assessed using optical and scanning electron microscopy. In addition, the wettability of the surfaces was examined through water contact angle experiments, and a numerical model was introduced to predict the water contact angle evolution over time. The results revealed that the sample coated with a 2.5 wt% lignin suspension exhibited the highest initial contact angle (114°), with a decreasing trend as the lignin fraction increases. Moreover, coatings with 3.5 wt% lignin and above exhibited lower surface coverage due to lignin particle aggregation and surface defects. By approximating the water droplet on the surface as a spherical cap, the introduced numerical model successfully predicted the time-dependent evolution of the water contact angle by showing strong alignment with experimental results. Taken altogether, we have showcased here a method for modifying coating properties-in a practical sense from water-absorbent to splash-proof-using readily available forest-based materials. This advancement is paving the way for sustainable protective packaging, aiming to replace styrofoam in the electronics and food industries.

Investigation of synergistic effects incorporating esterified lignin and guar gum composite aerogel for sustained oil spill cleanup

The recently developed aerogel demonstrates a high capacity for pollutant absorption, making it an environmentally friendly option for oily water treatment. In an effort to reduce the adverse effects of the black liquor accumulation in the pulp industry, this study focused on utilizing the mentioned abundant bio-resource lignin, which can be applied to various high-value applications such as 3D porous materials for oil spill cleanup. Lignin, precipitated from the black liquor, was esterified using maleic anhydride as the esterifying reagent to enhance the hydrophobicity. Then, the composite aerogel fabricated from esterified lignin and guar gum (GG) was successfully prepared through the facile freeze-drying, using glutaraldehyde (GA) as the cross-linker. The resulting aerogel exhibited high porosity values exceeding 95%, low density (27.4 mg/cm3), and an impressive absorption capacity of 32.5 g/g for sunflower oil. These results demonstrate the potential of black liquor utilization as a bio-waste source of lignin and highlight the cost-effective guar gum-esterified lignin composite aerogel, which exhibits remarkable oil absorption capabilities and environmental sustainability promotion.

Humic Acid-Functionalized Lignin-Based Coatings Regulate Nutrient Release and Promote Wheat Productivity and Grain Quality

The rational application of fertilizers is crucial for achieving high crop yields and ensuring global food security. The use of biopolymers for slow-release fertilizers (SRFs) development has emerged as a game-changer and environmentally sustainable pathway to enhance crop yields by optimizing plant growth phases. Herein, with a renewed focus on circular bioeconomy, a novel functionalized lignin-based coating material (FLGe) was developed for the sustained release of nutrients. This innovative approach involved the extraction and sustainable functionalization of lignin through a solvent-free esterification reaction with humic acid─an organic compound widely recognized for its biostimulant properties in agriculture. The primary objective was to fortify the hydration barrier of lignin by reducing the number of its free hydroxyl groups, thereby enhancing release control, while simultaneously harnessing the agronomic benefits offered by humic acid. After confirming the synthesis of functionalized lignin (FLGe) through 13C NMR analysis, it was integrated at varying proportions into either a cellulosic or starch matrix. This resulted in the creation of five distinct formulations, which were then utilized as coatings for diammonium phosphate (DAP) fertilizer. Experimental findings revealed an improved morphology and hardness (almost 3-fold) of DAP fertilizer granules after coating along with a positive impact on the soil's water retention capacity (7%). Nutrient leaching in soil was monitored for 100 days and a substantial reduction of nutrients leaching up to 80% was successfully achieved using coated DAP fertilizer. Furthermore, to get a fuller picture of their efficiency, a pot trial was performed using two different soil textures and demonstrated that the application of FLGe-based SRFs significantly enhanced the physiological and agronomic parameters of wheat, including leaf evolution and root architecture, resulting in an almost 50% increase in grain yield and improved quality. The results proved the potential of lignin functionalization to advance agricultural sustainability and foster a robust bioeconomy aligning with the premise "from the soil to the soil".

Lignin developmental patterns and Casparian strip as apoplastic barriers: A review

Lignin and Casparian strips are two essential components of plant cells that play critical roles in plant development regulate nutrients and water across the plants cell. Recent studies have extensively investigated lignin diversity and Casparian strip formation, providing valuable insights into plant physiology. This review presents the established lignin biosynthesis pathway, as well as the developmental patterns of lignin and Casparian strip and transcriptional network associated with Casparian strip formation. It describes the biochemical and genetic mechanisms that regulate lignin biosynthesis and deposition in different plants cell types and tissues. Additionally, the review highlights recent studies that have uncovered novel lignin biosynthesis genes and enzymatic pathways, expanding our understanding of lignin diversity. This review also discusses the developmental patterns of Casparian strip in roots and their role in regulating nutrient and water transport, focusing on recent genetic and molecular studies that have identified regulators of Casparian strip formation. Previous research has shown that lignin biosynthesis genes also play a role in Casparian strip formation, suggesting that these processes are interconnected. In conclusion, this comprehensive overview provides insights into the developmental patterns of lignin diversity and Casparian strip as apoplastic barriers. It also identifies future research directions, including the functional characterization of novel lignin biosynthesis genes and the identification of additional regulators of Casparian strip formation. Overall, this review enhances our understanding of the complex and interconnected processes that drive plant growth, pathogen defense, regulation and development.

Porous lignin-based composites for oil/water separation: A review

Frequent oceanic oil spill incidents and the discharge of industrial oily wastewaters have caused serious threats to environments, food chains and human beings. Lignin wastes with many reactive groups exist as the byproducts from bioethanol and pulping processing industries, and they are either discarded as wastes or directly consumed as a fuel. To make full use of lignin wastes and simultaneously deal with oily wastewaters, porous lignin-based composites have been rationally designed and prepared. In this review, recent advances in the preparation of porous lignin-based composites are summarized in terms of aerogels, sponges, foams, papers, and membranes, respectively. Then, the mechanisms and the application of porous lignin-based adsorbents and filtration materials for oil/water separation are discussed. Finally, the challenges and perspectives of porous lignin-based composites are proposed in the field of oil/water separation. The utilization of abundant lignin wastes can replace fossil resources, and meanwhile porous lignin-based composites can be used to efficiently treat with oily wastewaters. The above utilization strategy opens an avenue to the rational design and preparation of lignin wastes with high-added value, and gives a possible solution to use lignin wastes in a sustainable and environmentally friendly way.

Understanding the thermoplasticization mechanism of wood via esterification with fatty acids: A comparative study of the reactivity of cellulose, hemicelluloses and lignin

Thermoplastic materials can be obtained through solvent free wood esterification with fatty acid using trifluoroacetic anhydride (TFAA) as promoter. This study aims to investigate the mechanism of wood thermoplasticization mechanism by understanding the role of each wood component in esterification. High accessibility for acylation was found in cellulose indicated by the highest weight percent gain (WPG), followed by lignin and hemicelluloses. However, significant chemical structural changes were recorded for each spruce wood components observed by Fourier-transform infrared spectroscopy (FTIR) and cross-polarization/magic angle spinning solid state nuclear magnetic resonance (CP/MAS 13C NMR), promoting thus the improvement of their thermal properties detected by (thermogravimetric analysis) TGA and (differential scanning calorimeter) DSC. Cellulose as a major component wood played an important role in wood plasticization, indicated by the low softening temperature before degradation recorded by (thermomechanical analysis) TMA. Hemicelluloses presenting lower WPG, showed the same effect as cellulose on thermoplasticization supported by the low softening temperature observed by TMA and (scanning electron microscope) SEM. Acylated lignin did not show thermoplastic properties, but resulted in important hydrophobic aspects of materials.

Review of Current Prospects for Using Miscanthus-Based Polymers

Carbon neutrality is a requisite for industrial development in modern times. In this paper, we review information on possible applications of polymers from the energy crop Miscanthus in the global industries, and we highlight the life cycle aspects of Miscanthus in detail. We discuss the benefits of Miscanthus cultivation on unoccupied marginal lands as well as the rationale for the capabilities of Miscanthus regarding both soil carbon storage and soil remediation. We also discuss key trends in the processing of Miscanthus biopolymers for applications such as a fuel resources, as part of composite materials, and as feedstock for fractionation in order to extract cellulose, lignin, and other valuable chemicals (hydroxymethylfurfural, furfural, phenols) for the subsequent chemical synthesis of a variety of products. The potentialities of the biotechnological transformation of the Miscanthus biomass into carbohydrate nutrient media and then into the final products of microbiological synthesis are also examined herein.

Superhydrophobic cellulose paper with sustained antibacterial activity prepared by in-situ growth of carvacrol-loaded zinc-based metal organic framework nanorods for food packaging application

Cellulose paper packaging materials have gained considerable attention as substitutes for petroleum-based plastics owing to their biodegradability, renewability, flexibility, and good mechanical strength. However, high hydrophilicity and the absence of essential antibacterial activity limit their application in food packaging. In this study, a facile and energy-saving method was developed to improve the hydrophobicity of cellulose paper and endow it with a long-acting antibacterial effect by integrating cellulose paper substrate with metal-organic frameworks (MOFs). A dense and homogenous coating of regular hexagonal ZnMOF-74 nanorods was in-situ formed on a paper surface by layer-by-layer assembly followed by low-surface-energy polydimethylsiloxane (PDMS) modification to prepare a superhydrophobic PDMS@(ZnMOF-74)₅@paper. Excellent anti-fouling, self-cleaning, and antibacterial adhesion performances were obtained for this superhydrophobic paper. In addition, active carvacrol was loaded into the pores of ZnMOF-74 nanorods on PDMS@(ZnMOF-74)₅@paper to combine antibacterial adhesion together with bactericidal ability, ultimately resulting in a completely "bacteria-free" surface and sustained antibacterial performance. The resultant superhydrophobic papers not only showed overall migration values within the limit of 10 mg/dm² but also good stability against various harsh mechanical, environmental, and chemical treatments. This work gave insights into the potential of in-situ-developed MOFs-dopped coating as a functionally modified platform for preparing active superhydrophobic paper-based packaging.