Computational Studies of Cellulose-based Materials

Abstract

Cellulose is a remarkable organic biopolymer and sustainable raw material existing in nature. Over the past several decades, the study of cellulose materials has attracted significant attention in chemistry, physics, biomedicine, and engineering fields. The unique properties of cellulose such as high tensile strength, biocompatibility, and renewability, enabled its applications in numerous industries, including textiles, construction, biomedicine, pulp production, energy, and even electronics. However, in-depth research on the performance of cellulose-based materials and devices is still in high demand due to the complexity of cellulose and its derivatives.This thesis uses a theoretical modelling method to explore the cellulose-based materials structure, morphology and properties, and predict cellulose-based devices performance. The method is efficacious in understanding natural phenomena and solving practical problems through mathematical modelling, computer engineering, and data analysis. This thesis focuses on three computational studies: (I) cellulose nanomaterials, (II) cellulose composites, and (III) cellulose-based ion exchange membranes in aqueous organic redox flow batteries (AORFBs). The first part presents theoretical insights into cellulose nanocrystal (CNC), surface modifications, and regenerated cellulose. The second part includes numerical models of light propagation in cellulose composites such as transparent wood, and the third part involves modelling and simulation of AORFBs.To my supervisor in bachelor and master stage, Prof. Xianping Chen, from Chongqing University, for always pushing me forward. Your never-give-up attitude, relentless drive, and ability to lead have left an indelible mark on my mind.Dear Karen Margrethe Ekman and Bert Ekman: you have been like lovely grandparents to me, offering invaluable support during my time in Sweden. I cherish every moment spent with you both. I sincerely hope for your continued good health and may joy and happiness accompany you forever.I would also like to thank Claes Rytsner for your consistent help, friendship, and for offering me a wonderful apartment.Lastly, a heartfelt thanks to my parents and relatives for their understanding and backing. To my girlfriend, Lijun Peng, I'm grateful for your unwavering support and companionship. This period stands out as one of the happiest times of my life.Having each one of you by my side has truly been a blessing.