Browsing by Author "Henn, K. Alexander"
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- Biobased Nanomaterials─The Role of Interfacial Interactions for Advanced Materials
A2 Katsausartikkeli tieteellisessä aikakauslehdessä(2023-03-08) Österberg, Monika; Henn, K. Alexander; Farooq, Muhammad; Valle-Delgado, Juan JoséThis review presents recent advances regarding biomass-based nanomaterials, focusing on their surface interactions. Plant biomass-based nanoparticles, like nanocellulose and lignin from industry side streams, hold great potential for the development of lightweight, functional, biodegradable, or recyclable material solutions for a sustainable circular bioeconomy. However, to obtain optimal properties of the nanoparticles and materials made thereof, it is crucial to control the interactions both during particle production and in applications. Herein we focus on the current understanding of these interactions. Solvent interactions during particle formation and production, as well as interactions with water, polymers, cells and other components in applications, are addressed. We concentrate on cellulose and lignin nanomaterials and their combination. We demonstrate how the surface chemistry of the nanomaterials affects these interactions and how excellent performance is only achieved when the interactions are controlled. We furthermore introduce suitable methods for probing interactions with nanomaterials, describe their advantages and challenges, and introduce some less commonly used methods and discuss their possible applications to gain a deeper understanding of the interfacial chemistry of biobased nanomaterials. Finally, some gaps in current understanding and interesting emerging research lines are identified. - Interfacial catalysis and lignin nanoparticles for strong fire- and water-resistant composite adhesives
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2022-09-07) Henn, K. Alexander; Forssell, Susanna; Pietiläinen, Antti; Forsman, Nina; Smal, Ira; Nousiainen, Paula; Bangalore Ashok, Rahul Prasad; Oinas, Pekka; Österberg, MonikaWood is increasingly replacing concrete to reduce CO2 emissions in buildings, but fossil-based adhesives are still being used in wood panels. Epoxidized lignin adhesives could be a potential replacement, but their preparation has so far required low-molecular weight lignin and long reaction times. Here we show a new efficient method to produce epoxidized kraft lignin (EKL) from regular kraft lignin by using interfacial catalysis. We demonstrate that EKL combined with biocolloids in the form of lignin nanoparticles (LNPs) produces a strong adhesive comparable to commercially available ones when cross-linked at 130-160 °C for only 3-5 minutes. The adhesive was free of phenol or formaldehyde, had a lignin content of over 80% and still showed impressive wet strength and incredible thermal stability. The process was shown to be scalable and environmentally more sustainable than resins from fossil-based feedstock or currently available ones from renewable resources.