Exploring Large Ductility in Cellulose Nanopaper Combining High Toughness and Strength

Abstract

This doctoral dissertation was completed in the frame of the FiDiPro-project ALL-CELL (From ultralight to ultra-strong all-cellulose composites via "green" processing) which was enabled by the financial support from Business Finland (former TEKES, Finnish Funding Agency for Innovation), Stora Enso Oyj, UPM-Kymmene Oyj and the collaboration with Fibertus Oy and Separation Research Ab Oy as well. The work was carried out from Autumn 2016 t0 Spring 2020 mainly at Aalto University in Finland and partly at Mines ParisTech-Center of Materials Forming (CEMEF) in Sophia Antipolis, France. The grants or scholarships from Foundation for Aalto University Science and Technology, Aalto CHEM school's funding (FinnCERES), Walter Ahlströmin Foundation and Finnish Forest Products Engineers' Association supported the finalization of the thesis. All funding over the years is greatfully acknowleged. First, I wish to express my deepest appreciation to my supervisor and advisor Prof. Tatiana Budtova for giving me the opportunity to pursue PhD abroad after achieving my master's degree in China, for guiding me consistently throughout my PhD journey in Finland and France, for supporting my participation in conferences over the world and for supporting me whenever your help is needed. Your encouragement-dominated attitude as a supervisor and rigorous attitude as a scientist will be a standard example in my future academic career. I also wish to show my gratitude to my thesis advisors Prof. Herbert Sixta and Prof. Michael Hummel. Thank you, Herbert, for your support and advises during my PhD study in Biorefineries group since the first day I came Bio2 department. Thank you, Michael, for helping me solve all the issues and your valuable discussions concerning experimental results and writing. I feel extremely lucky to spend my doctoral time with you all. My deep gratitude also goes to all the co-authors: Dr. Daisuke Sawada, Dr. Wenchao Xiang, Dr. Long Bai, Dr. Christophe Pradille (Mat Xper) and Prof. Jean-Luc Bouvard (CEMEF). It was my great pleasure to work with and learn from you. All the achievements on the research work are inseparable from your contribution. I warmly thank Prof. Jun Zhang, Prof. Johannes Ganster and Prof. Mohamed Naceur Belgacem for carefully examining this thesis. I also thank all the project partners from Business Finland and industry for insightful discussions and the encouragement during every half-year project meeting.

Preparation and benchmarking of novel cellulose nanopaper

“…A similar trend to this was observed with increasing grammage of nanopaper samples (Kontturi et al 2021 ). Increases in tensile index and ductility have been also reported with an increase in hemicellulose content (Chen et al 2020 ; Taylor et al 2020 ) but for our samples the chemical composition was not varied. However, during mechanical refining there is an increase in mass fraction of fines which strengthens fiber–fiber bonding, explaining enhancement in sheet mechanical strength.…”

“…Nanocellulose is relatively cheap and can be obtained from biodegradable feedstocks like wood and other lignocellulosics rendering it highly suitable for sustainable barrier material development. There has been extensive work done based on the chemical composition of original starting pulp, mainly the hemicellulose content, which makes a difference in porosity, strength and barrier properties of the final nanopaper product (Chen et al 2020 ; Kontturi et al 2021 ; Taylor et al 2020 ). However, there have been no investigations reported for nanocellulose which talks about scalability, energy consumption requirement for reaching good barrier properties comparable with plastic-based films.…”

Exploring digital image correlation technique for the analysis of the tensile properties of all-cellulose composites

“…4). It is worth noting that ACCs P60 is transparent (optical transmittance * 80% at 550 nm) but still with high haze ([ 70% at 550 nm), which makes it promising as photonic material for optoelectronic applications such as solar cells, as haze increases light scattering and absorption (Hou et al 2020;Chen et al 2020b). The digital photographs of ACC P60 confirm high transmittance and high haze ( Fig.…”

Chemistry and Nanotechnology‐Oriented Strategies toward Nanocellulose for Human Water Treatment

“…Biomass based substrates for the creation of nanocellulose materials are considered as a precious commodity, which provide abundant resources for biofuels and chemicals (Figure 2). [44][45][46][47][48][49] Using the above mentioned technologies, nanocelluloses were prepared from numerous cellulosic sources, including soft and hard woods, corn, sugar beet pulp, miscanthus, banana, sisal, opuntia, ficus-indica (cactus), flax, potato, bagasse, wheat straw, bamboo, Luffa cylindrica, grape pomace, as well as some seaweed. [50][51][52] The morphological characteristics of the produced cellulose derived adsorbents mainly depend on the morphological characteristics of the original fibers.…”