Strong, Ductile, and Waterproof Cellulose Nanofibril Composite Films with Colloidal Lignin Particles

| openaire: EC/H2020/720303/EU//ZELCORBrittleness has hindered commercialization of cellulose nanofibril (CNF) films. The use of synthetic polymers and plasticizers is a known detour that impairs biodegradability and carbon footprint of the product. Herein, we utilize a variety of softwood Kraft lignin morphologies to obtain strong and ductile CNF nanocomposite films. An optimum 10 wt % content of colloidal lignin particles (CLPs) produced films with nearly double the toughness compared to a CNF film without lignin. CLPs rendered the films waterproof, provided antioxidant activity and UV-shielding with better visible light transmittance than obtained with irregular lignin aggregates. We conclude based on electron microscopy, dynamic water sorption analysis, and tp-DSC that homogeneously distributed CLPs act as ball bearing lubricating and stress transferring agents in the CNF matrix. Overall, our results open new avenues for the utilization of lignin nanoparticles in biopolymer composites equipped with versatile functionalities for applications in food packaging, water purification, and biomedicine.Peer reviewe

Application of Cellulose-Based Materials as Water Purification Filters; A State-of-the-Art Review

Water scarcity, identified as the most serious global risk by the World Economic Forum, poses significant challenges due to its potential impact over the next decade. This study focuses on addressing the pressing issues of water scarcity and water quality through the use of cellulose-based materials for manufacturing water filters. Industrial wastewater containing dyes and heavy metal ions is a major contributor to water pollution, affecting underground water sources. Copper, mercury, chromium, lead, and tin are among the most common and environmentally damaging heavy metal ions due to their high toxicity, low biodegradability, and persistence in the food chain. Water purification processes are crucial for ensuring safe consumption. Bio-compatible and renewable materials have gained attention for water treatment applications in recent years. Cellulose-based materials, such as cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs), possess unique characteristics including biodegradability, suitable aspect ratio, thermal stability, high strength, stiffness, renewability, and accessibility. This research aims to review the utilization of cellulose-based materials, particularly modified CNC and CNF aerogels, for manufacturing water filters. These materials exhibit high porosity, large specific surface area, and functional groups on their surfaces, making them promising adsorbents for removing water pollutants such as heavy metals, organic dyes, pharmaceutical waste, and oils. Our study demonstrates that modified CNFs and CNCs have shown an exceptional absorption capacity of approximately 98% for heavy metals. By focusing on the specific application of cellulose-based materials for water filtration, this research contributes to the development of effective and sustainable solutions for water purification, addressing the critical challenges posed by water scarcity and pollution

Recent developments in nanocellulose-based biodegradable polymers, thermoplastic polymers, and porous nanocomposites

International audienceNanocellulose has generated a great deal of interest as a source of nanometer-sized reinforcement, because of its good mechanical properties. In the last few years, nanocellulose has also attracted much attention due to environmental concerns. This review presents an overview of recent developments in this area, including the production, characterization, properties, and range of applications of nanocellulose-based biodegradable polymers, thermoplastic polymers, and porous nanocomposites. After explaining the unique properties of nanocellulose and its various preparation techniques, an orderly introduction of various nanocellulose-reinforced biodegradable polymers such as starch, proteins, alginate, chitosan, and gelatin is provided. Subsequently, the effects of nanocellulose on the properties of thermoplastic polymers such as polyamides, polysulfone, polypropyrol, and polyacronitril are reported. The paper concludes with a presentation of new finding and cutting-edge studies on nanocellulose foam and aerogel composites. Three different types of aerogels, i.e., pristine nanocellulose-based aerogels, modified nanocellulose-based aerogels, and nanocellulose-based templates for aerogels, are discussed, as well as their preparation techniques and properties. In the case of foam composites, the research focus has been on two major preparation techniques, i.e., solvent-mixing/foaming and melt-mixing foaming, their respective challenges, and the properties of the final composites. In some cases, a comparison study between cellulose nanocrystals and cellulose nanofiber-reinforced biodegradable polymers, thermoplastics, and porous nanocomposites was carried out. Considering the vast amount of research on nanocellulose-based composites, special emphasis on such composites isprovided at the end of the review