Browsing by Author "Svanedal, Ida"
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- Innovative approaches to mitigating microplastic pollution in effluents and soilsPublication . Magalhães, Solange; Alves, Luís; Medronho, Bruno; Svanedal, Ida; Norgren, Magnus; Rasteiro, Maria GraçaMicroplastic pollution represents a significant environmental challenge, as microplastics accumulate in effluents and soils, causing serious risks to ecosystems and human health. Efficient removal of these contaminants is essential to mitigate their potential adverse effects. This review summarizes and critically analyses current methods for the removal of microplastics from effluents and soils, focusing on their effectiveness, advantages, and limitations. Conventional techniques—including filtration, flotation, chemical coagulation, flocculation, and adsorption—are discussed in the context of wastewater treatment and soil remediation. Emerging approaches, such as flocculation processes with special focus on the application of bio-based flocculants, are also highlighted as promising solutions. Key challenges in microplastic removal, including the diversity of microplastic types, their small size, and the complexity of environmental matrices, are addressed. This work intends to contribute to the urgent need for further research to develop more efficient and sustainable strategies for microplastic removal from environmental systems.
- Lignin enhances cellulose dissolution in cold alkaliPublication . Costa, Carolina; Medronho, Bruno; Eivazi, Alireza; Svanedal, Ida; Lindman, Björn; Edlund, Håkan; Norgren, MagnusAqueous sodium hydroxide solutions are extensively used as solvents for lignin in kraft pulping. These are also appealing systems for cellulose dissolution due to their inexpensiveness, ease to recycle and low toxicity. Cellulose dissolution occurs in a narrow concentration region and at low temperatures. Dissolution is often incomplete but additives, such as zinc oxide or urea, have been found to significantly improve cellulose dissolution. In this work, lignin was explored as a possible beneficial additive for cellulose dissolution. Lignin was found to improve cellulose dissolution in cold alkali, extending the NaOH concentration range to lower values. The regenerated cellulose material from the NaOH-lignin solvents was found to have a lower crystallinity and crystallite size than the samples prepared in the neat NaOH and NaOH-urea solvents. Beneficial lignin-cellulose interactions in solution state appear to be preserved under coagulation and regeneration, reducing the tendency of crystallization of cellulose.
- Perspectives on the Lindman Hypothesis and cellulose interactionsPublication . Norgren, Magnus; Costa, Carolina; Alves, Luís; Eivazi, Alireza; Dahlström, Christina; Svanedal, Ida; Edlund, Håkan; Medronho, BrunoIn the history of cellulose chemistry, hydrogen bonding has been the predominant explanation when discussing intermolecular interactions between cellulose polymers. This is the general consensus in scholarly textbooks and in many research articles, and it applies to several other biomacromolecules’ interactions as well. This rather unbalanced description of cellulose has likely impacted the development of materials based on the processing of cellulose—for example, via dissolution in various solvent systems and regeneration into solid materials, such as films and fibers, and even traditional wood fiber handling and papermaking. In this review, we take as a starting point the questioning of the general description of the nature of cellulose and cellulose interactions initiated by Professor Björn Lindman, based on generic physicochemical reasoning about surfactants and polymers. This dispute, which became known as “the Lindman hypothesis”, highlights the importance of hydrophobic interactions in cellulose systems and that cellulose is an amphiphilic polymer. This paper elaborates on Björn Lindman’s contribution to the subject, which has caused the scientific community to revisit cellulose and reconsider certain phenomena from other perspectives.
- Stacking self-gluing cellulose II films: a facile strategy for the formation of novel all-cellulose laminatesPublication . Dahlström, Christina; Duan, Ran; Eivazi, Alireza; Magalhães, Solange; Alves, Luís; Engholm, Magnus; Svanedal, Ida; Håkan Edlund; Medronho, Bruno; Norgren, MagnusCellulose laminates represent a remarkable convergence of natural materials and modern engineering, offering a wide range of versatile applications in sustainable packaging, construction, and advanced materials. In this study, novel all-cellulose laminates are developed using an environmentally friendly approach, where freshly regenerated cellulose II films are stacked without the need for solvents (for impregnation and/or partial dissolution), chemical modifications, or resins. The structural and mechanical properties of these all-cellulose laminates were thoroughly investigated. This simple and scalable procedure results in transparent laminates with exceptional mechanical properties comparable to or even superior to common plastics, with E-modulus higher than 9 GPa for a single layer and 7 GPa for the laminates. These laminates are malleable and can be easily patterned. Depending on the number of layers, they can be thin and flexible (with just one layer) or thick and rigid (with three layers). Laminates were also doped with 10 wt% undissolved fibers without compromising their characteristics. These innovative all-cellulose laminates present a robust, eco-friendly alternative to traditional synthetic materials, thus bridging the gap between environmental responsibility and high-performance functionality.
- Tuning the properties of regenerated cellulose: Effects of polarity and water solubility of the coagulation mediumPublication . From, Malin; Larsson, Per Tomas; Andreasson, Bo; Medronho, Bruno; Svanedal, Ida; Edlund, Hakan; Norgren, MagnusIn this study, the effect of different alcohols and esters as a coagulation medium in the regeneration of cellulose dissolved in an aqueous LiOH-urea-based solvent was thoroughly investigated using various methods such as solid state NMR, X-ray diffraction, water contact angle, oxygen gas permeability, mechanical testing, and scanning electron microscopy. It was observed that several material properties of the regenerated cellulose films follow trends that correlate to the degree of cellulose II crystallinity, which is determined to be set by the miscibility of the coagulant medium (nonsolvent) and the aqueous alkali cellulose solvent rather than the nonsolvents' polarity. This article provides an insight, thus creating a possibility to carefully tune and control the cellulose material properties when tailor-made for different applications [GRAPHICS]