Public defence in Bioproduct technology, M.Sc.(Tech.) Karl Alexander Henn

Title of the thesis: Scalable Surface Chemistry for Lignin Modification - Creating Value for a Forest-Based Society

Doctoral student: M.Sc.(Tech.) Karl Alexander Henn
Opponent: Professor Lars Wågberg, KTH Royal Institute of Technology, Sweden
Custos: Professor Monika Österberg, Aalto University School of Chemical Engineering, Department of Bioproducts and Biosystems

Finland’s forest sector accounts for close to 20% of the value of the country’s exported goods, but the value could be much higher. Lignin is a highly abundant wood material that is produced as a byproduct in pulp and paper production. Lignin is nevertheless difficult to apply, and most of it is therefore incinerated for energy. Lignin’s usefulness could nevertheless be enhanced with new valorization technologies. This would provide the pulp and paper industry with revenue streams beyond paper products, and advancements in this area are therefore important. 
Alexander Henn has developed multiple methods to apply lignin as colloidal particles. One theme in the thesis was exploring ways to combine lignin and other functional water-insoluble compounds in water-based systems. This could be done both by entrapping hydrophobic materials within particles and adsorbing hydrophobic compounds on the surface of the particles. For example, phase change materials and lignin could be used to make hybrid particles that were capable of storing and releasing heat, and durable surface coatings and adhesives could be prepared by combining lignin particles with hydrophobic epoxies. By altering lignin’s structure, Henn was also able to prepare particle so small that they were completely transparent. Thin films of these particles were superhydorphilic and useful as optical antifogging coating, while thicker films got brightly colored due to light interference phenomenon, and could likely be useful for sensor applications. Henn also developed new ways to perform chemical modifications to reduce the use of expensive and harmful chemicals and improve the processes’ scalability.
In conclusion, Henn’s thesis demonstrates multiple useful ways to apply lignin in several diverse applications, and new useful lignin-modification methods that could be used in applications beyond what was demonstrated in the thesis.

Thesis available for public display 10 days prior to the defence
Contact information:
M.Sc. (Tech.) Karl Alexander Henn
[email protected] 

 Doctoral theses in the School of Electrical Engineering

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