A group of young researchers from Austria, Belgium, Canada, Finland and Sweden were selected for the MWP Young Researchers’ Program 2020/2021. Due to the situation with the corona pandemic the 2020 Marcus Wallenberg Prize Event in Stockholm was cancelled, and in 2021 the Event was held digitally. On October 25 there was a special session for the Young Resarchers, and on October 26 a Digital Ceremony & Symposium was held.

The Young Researchers’ abstracts are published below:

1: Phonon-Engineering of Hygroscopic Nanocellulose-Based Foams for Thermal Insulation

Author(s): Varvara Apostolopoulou-Kalkavoura, Lennart Bergström

Corresponding author: Varvara Apostolopoulou-Kalkavoura

Affiliation: Stockholm University

E-mail: varvara.apostolopoulou@mmk.su.se

Abstract:

Cellulose nanomaterials (CNM) obtained from wood combine properties such as high strength and stiffness, tunable surface chemistry, and nanoscale dimensions that enable low-density foams with very low thermal conductivity to be produced by aqueous processing. Replacing fossil-based insulating materials with superinsulating nanocellulose-based foams based on renewable and Earth-abundant building blocks would reduce the carbon footprint of the building sector and reduce the energy needed to maintain a pleasant indoor climate. We have exploited both cellulose’s intrinsic anisotropy and the fibril alignment induced by the directional ice crystal growth to produce ice-templated anisotropic cellulose nanofibril foams that displayed superinsulating thermal conductivity perpendicular to the fibrils’ direction over a wide range of RH (5-80%). We showed that using thin cellulose nanofibrils resulted in foams with thermal conductivity much lower than the value of air at 295 K and 35% relative humidity (RH). Molecular simulations indicated that the competing mechanisms of interfacial phonon scattering due to moisture-induced swelling and the replacement of air with water in the pores is responsible for the minimum thermal boundary conductance at intermediate RH. Phonon-engineering the heat transport of hygroscopic cellulose foams opens up possibilities for effective thermal insulation in different climates.

Key words:

Cellulose nanomaterials, superinsulating foams, thermal conductivity, hygroscopic, phonon scattering

2: Confined and Water-Promoted (Nano)Cellulose Modifications

Author(s): Marco Beaumont, Orlando Rojas and Thomas Rosenau

Corresponding author: Marco Beaumont

Affiliation: University of Natural Resources and Life Sciences Vienna and University of Würzburg, Würzburg

E-mail: Marco.beaumont@boku.ac.at        

Abstract:

Cellulose nanofibers offer unique intrinsic properties and huge potential to be assembled into outstanding functional materials. However, current limitations in chemical surface engineering of celluloses still hamper the advancement in this field.

With my research, I am aiming to induce a paradigm shift in general field of (nano)cellulose chemistry by introducing new chemical concepts to modify cellulose in a spatially selective and confined manner. I established a biomimetic surface esterification method based on reaction of N-acylimidazoles, which is sustainable, straight-forward, and water-promoted, enabling the production of a broad range of functional cellulose nanofibers. Similar to the well-known TEMPO-oxidation, the aqueous esterification is a highly regioselective reaction to the primary hydroxyl group. The reaction is surface-confined and no polymer degradation, cross-linking, nor changes in crystallinity occur.

This aqueous surface modification overcomes current limitations in cellulose chemistry and enables a simple, resource-efficient, green, and versatile avenue to esterified nanocelluloses. It is expected to have a widespread influence on the field of cellulose chemistry, also facilitating the large-scale production of functional nanocelluloses.

Key words:

Surface Esterification, Acetylated cellulose, Regioselective Functionalization, Acylimidazole

3: In situ R2R spray deposition of flexible nanocellulose-based supercapacitors studied using advanced X-ray scattering

Author(s): Calvin J. Brett, Stephan V. Roth, and L. Daniel Söderberg

Corresponding author: Calvin J. Brett

Affiliation: KTH Royal Institute of Technology and Deutsches Elektronen Synchrotron

E-mail: calvinbr@kth.se        

Abstract:

The industrial production of sustainable devices experiences a massive increase of attention over the last years. The global economy is initiating projects to minimize the use of fossil resources. However, it is yet unclear how sustainable bio-based devices perform and degrade under environmental influences and how we could tackle possible drawbacks. We believe that wood-based cellulose is a key enabler for hierarchical bio-nanocomposites with unprecedented properties as lightweight, flexibility and durability. PEDOT:PSS is nowadays widely used as high performance conductive polymer in the field of bioelectronics, solar cells, and supercapacitors. Due to its water-solubility, it fulfils the sustainable approach of using less solvents to achieve environmentally friendly devices. The aim of this spray deposition study is to correlate directly the inner morphology of the deposited thin films with its macro-scale physical properties. Herein we used spray deposition as industrial deposition technique on a roll-to-roll coater to fabricate large-scale films with unprecedented low surface roughness. The sprayed flexible and conductive bionanocomposite are fabricated to provide high energy densities for battery and supercapacitor technologies. We investigated the effect of different layer formation parameters such as drying times, temperature and additives, in particular organization of PEDOT:PSS on CNF and film formation mechanism with spray coating method by means of surface sensitive X-ray scattering. We thus achieved a better understanding of the morphology of such films and their electrochemical performance in order to create better energy storage and healthcare devices in the future.

Key words:

Sustainability, X-rays, Nanocomposites

4: Making Strong Cellulose Nanopaper Highly Ductile and Tough by Ionic Liquid Induced Disordering of Nanofibrils

Author(s): Feng Chen, Wenchao Xiang, Daisuke Sawada, Tatiana Budtova

Corresponding authors: Feng Chen, Tatiana Budtova

Affiliation: Aalto University, ETH Zürich, PSL Research University-Mines ParisTech

E-mail: fechen@ethz.ch , tatiana.budtova@mines-paristech.fr        

Abstract:

Renewable cellulose nanopaper of high-transparency and high-strength is highly desirable and has been reported as a replacement for plastics in “green” flexible electronics. However, a long-standing problem for these nanopapers is that they suffer from low ductility. Here we report a remarkably facile and effective nanostructuring strategy to fabricate transparent nanopaper with unprecedented combinations of large ductility, high strength and ultrahigh toughness. The processing route involves mechanical fibrillation of wood fibers followed by a post-treatment: dispersing the obtained cellulose nanofibrils (CNF) in ionic liquid (IL)-water mixture. While initial CNF-in-water contained bundles of assembled nanofibrils, the suspension of CNF in IL-water resulted in bundles’ delamination. The concentration of IL is below the dissolution limit of cellulose and hemicellulose. Dynamic rheology revealed almost 300 times increase of storage and loss moduli of CNF-IL-water suspensions as compared to their CNF-water counterparts, indicating the formation of strong entangled nano-network of highly disordered thin fibrils-further supported by cryo-TEM imaging. Nanopaper is then prepared by filtration of CNF-IL-water suspension and washing out of IL. The resulting nanopaper is transparent with an unprecedented combination of high strength up to 260 MPa, elongation as large as 35 % and a corresponding toughness 51 MJ/m3. Reference: Chen, Feng, et al. ACS nano 14.9 (2020): 11150-11159.

Key words:

Cellulose nanofibrils, Ionic liquid, Nanopaper, Swelling, Disordering, Ductility, Transparency

5: Paper strength improved by O-delignification at high kappa numbers

Author(s): Cláudia Esteves, Olena Sevastyanova, Sören Östlund, Elisabet Brännvall

Corresponding author: Cláudia Esteves

Affiliation: RISE

E-mail: claudia.esteves@ri.se        

Abstract:

Kraft pulping and oxygen delignification are important processes in the pulp and paper sector. Is oxygen delignification capable to increase pulp production and save energy? Can it be used in a better way, increasing the mechanical properties? The economic and environmental benefits of oxygen delignification over the kraft process have potential to be improved to a greater extent without compromising the fiber properties. Due to the oxidation of lignin and some carbohydrates, it is possible to increase the amount of charges present in the fibers. This leads to an increase in swelling and, consequently, to a better fiber conformation and bonding. A pulp with higher kappa number from the cooking process, will decrease the cooking energy demand and carbohydrate degradation, and will be an excellent stage to start an oxygen process. By starting from a high kappa number after cooking and continue with oxygen delignification until kappa 30 or 25, it is possible to reduce the refining energy, up to 55%, needed to achieve the same or even higher mechanical strength. Tensile index can increase up to 14 % with oxygen delignification, for the same sheet density, when compared to the kraft cook. The increase in refinabilty and tensile strength is due to better conformability of fibers with higher amount of charges.

Key words:

Fiber charges, fibrillation, energy saving, tensile index, swelling

6: Estimation of forest structure and tree quality of hardwood forest stands by combining novel remote sensing data

Author(s): Jasper Feyen

Corresponding author: Jasper Feyen

Affiliation: Ghent University

E-mail: Jasper.feyen@ugent.be        

Abstract:

Accurate information on tree and forest stand quality is key in optimizing forest value chain and for reaching a sustainable forest management in general. When quantifying forest stand or tree (economic) quality, it is important to obtain accurate and up-to-date information on the three-dimensional structure of these forests. 

Remote Sensing has been successfully applied for the retrieval of the structural characteristics of forests (Latifi, 2012).  Recent and future freely available remote sensing systems, such as the Global Ecosystem Dynamics Investigation (GEDI), NISAR and BIOMASS are promising in the assessment of forest stand structural attributes on a regional scale. These sensors will provide up-to-date information on forests’ biomass and height as never seen before. My PhD research aims at combining these newly available optical, SAR and space-LiDAR data to assess forest structure and tree/stem quality of hardwood forest stands on a regional scale. Field inventory data will be coupled with remote sensing data, aiming at creating accurate maps of forest stand quality. First, methods will be developed to quantify the structure of simple, homogenous temperate hardwood stands. In a later stage, also tropical forest will be addressed. By providing spatial explicit maps of forest stand quality in both temperate as tropical hardwood forests we facilitate forest precision planning and regional monitoring and management.

Key words: Remote sensing, tree quality, GEDI, hardwood, regional mapping, data fusion

7: Characterization of functionalized wood materials by chemical force microscopy

Author(s): Claudia Gusenbauer, Etienne Cabane, Johannes Konnerth

Corresponding author: Claudia Gusenbauer

Affiliation: Institute of Wood Technology and Renewable Materials, BOKU-University of Natural Resources and Life Sciences, Vienna

E-mail: claudia.gusenbauer@boku.ac.at        

Abstract:

Wood materials are usually applied in the construction and furniture industry, but research aims at expanding the current wood utilizations. For instance, it has been shown that the structure of wood can be used as a matrix to create advanced functionalized materials. In several approaches, such materials are achieved by the chemical modification of the inner cell wall surface by polymerization procedures. These modification techniques enable to create novel wood products such as wood based water filters for waste water purification.

Within the framework of wood functionalization, a need for adapted characterization methods to fully understand and exploit the wood structures developed. The aim of our research project is to visualize the effect and changes in the wood cell wall caused by the different wood modifications. Therefore, we are applying a high-resolution microscopy technique, chemical force microscopy, to identify the impact of certain chemical treatments on wood. In this method, a sharp chemically modified tip with a radius of some nanometers is scanned over a flat functionalized surface. The interaction between the tip and the surface of the sample is analyzed, which provides topographical and chemical maps with nanometer spatial resolution. With this method, we could visualize polymerized wood areas and the introduced functionalities could be verified on the wood cell wall level.

Key words:

atomic force microscopy, chemical force microscopy, functionalized wood, wood structure

9: Learn from the past, look to the future – modelling forest disturbances in a changing world

Author(s): Juha Honkaniemi

Corresponding author: Juha Honkaniemi

Affiliation: Natural Resources Institute Finland (LUKE)

E-mail: juha.honkaniemi@luke.fi        

Abstract:

Forest disturbance regimes are changing around the world with the warming climate. One significant factor mediating disturbances is the landscape structure affected heavily by past land-use and forest management practices. Long-term time series, such as National Forest Inventories, measuring forest dynamics in large spatial context are essential to analyze changes over time. For example, our case study analyzing the occurrence of Heterobasidion root rot in Finland revealed that historical land-use and forest management legacies were more important variables for Heterobasidion epidemiology than current stand structure or site conditions. Analyzing historical records and combining them with novel process-based models can help us to understand the drivers of change in our forests. With different modelling tools, we can also quantify the effect of our actions on disturbance risks in the changing climate. A simulation study on the effects of landscape structure and composition on natural disturbances showed how the spatial configuration of Norway spruce in the landscape affected both wind and bark beetle disturbances. Mixed stand structures had best resilience to climate change whereas resistance to different disturbance agents varied between configuration scenarios. Results such as the above provide support for the ecosystem managers to foster resilience of forests to climate change.

Key words:

forest dynamics, disturbance ecology, climate change, modelling

10: Early detection of forest stress caused by the Europen spruce bark beetle using remote sensing technique

Author(s): Langning Huo, Henrik Persson, Eva Lindberg

Corresponding author: Langning Huo

Affiliation: Swedish University of Agricultural Sciences

E-mail: langning.huo@slu.se        

Abstract:

“The spruce bark beetle is the insect causing most damages to our spruce forests” according to the Swedish Forest Agency. In 2018, it destroyed 3-4 million m3 of timber in Sweden, and approximately 40 million m3 in central Europe. Accelerated by global warming, the average annual damages expected for 2021–2030 is almost six times higher than observed in 1971–2010. This is a threat to the sustainable development of forestry. One crucial strategy of damage control is removing damaged trees to prevent the spread in time, usually before the end of June in Sweden. However, tree crowns are still in the early stage of infestations and show subtle visible changes. How to find the infested trees that should be removed? How early is it possible to plan the sanitation felling in advance?

Remote sensing techniques have recently been proven to achieve early detection. In the past, the records of the earliest detection were June, while our latest research presents a method that achieved it before April from Sentinel-2 satellite images. Our innovative idea is that detecting stress rather than damage would be a more efficient way to achieve early detection when using remote sensing data. A new vegetation index NDRS was developed based on this idea for large-area mapping. Implementing this idea would provide forest owners necessary monitoring of their forests and benefit damage control and sustainable management. The generated maps could also be a database for further studies about trends and environmental factors.

Key words:

Forest stress, Europen spruce bark beetle, early detection, remote sensing

11: ‘Lignin and extractives first’ conversion of lignocellulosic residual streams using UV-LEDs

Author(s): Jonna Hynynen, Alexander Riddell, Abdenour Achour, Zoltan Takacs, Mats Wallin, Jim Parkås, Diana Bernin

Corresponding author: Jonna Hynynen

Affiliation: Chalmers

E-mail: jonhy@chalmers.se        

Abstract:

Studies on the discoloration of paper upon storage was first reported in the late 19th century. Today we know this process as “photoyellowing of paper”. Photoyellowing occur due to the exposure of lignin to sunlight (UV-light) and oxygen. Lignin is a poly-aromatic molecule, present in wood at concentrations ranging from 15-30%.

Due to its poly-aromatic nature it has the potential to substitute fossil derived precursors in the chemical industry. The conversion of lignin into valuable small molecules has been intensively researched but challenges remain. Both because of the recalcitrant nature of processed lignin, but also due to the high temperatures and increased pressure that is used upon conversion of lignin resulting in an energy intensive process. Inspired by early research on the photoyellowing of paper, we sought out to mimic the natural photo-conversion processes of lignin and extractives using UV-light from UV-LEDs. Our aim was to valorize a commonly found residual stream from the paper and pulp industry—sawdust. UV-LEDs are a cheap, versatile, and energy efficient source for UV-light, compared to existing mercury lamps. In a process at ambient temperature and pressure and without the use of catalyst, we have shown that lignin and extractives can be valorized using light from UV-LEDs. Simplified lignin model compounds were used to pinpoint chemical reactions during irradiation. The rate of conversion upon irradiation of the model compounds was found to be 0.7–2.3 g L-1 h-1.

Key words:

photochemistry, UV-LEDs, lignin, model compounds, residual streams

12: Material concepts for the production of electrode papers via standard paper-making techniques

Author(s): Patrik Isacsson, Xin Wang, Andreas Fall, Desalegn Mengistie, Emilie Calvie, Hjalmar Granberg, Göran Gustafsson, Magnus Berggren, Isak Engquist

Corresponding author: Patrik Isacsson

Affiliation: Linköping University

E-mail: patrik.isacsson@liu.se        

Abstract:

From batteries to displays, electrodes are key components in most electrical devices. Over the past decades, numerous works has demonstrated cellulose-based, green electrodes. Although the cellulose itself is an electrical insulator, cellulose has excellent properties to act as a hosting scaffold for conducting and/or electroactive materials. However, as most work has been done on nanocellulose composites, the material concepts are not translatable to existing production assets such as paper machines. In order to overcome this obstacle, this project investigates how the material concepts can be adapted to cellulosic fibers and paper-making protocols.

The present work focused on highly conducting papers for the use in printed electronics. A spontaneous adhesion of exfoliated graphite on softwood kraft fibers was exploited to produce papers with an in-plane conductivity of 107 S/cm and a double-layer capacitance of 9.2 mF/cm2. These properties were exploited to successfully demonstrating the paper as a combined printing substrate, back collector and counter electrode in a printed electrochromic display. The research on paper electrodes such as this opens for a fast-track towards collaboration and product development together with the electronics and batteries industries, to enable the realization of helpful technologies for our transition into a sustainable society.

Key words:

electronic paper, printed electronics, electrochromic display, nanographite, graphene, cellulose, self-assembly

13: Advance imaging of lignocellulose materials: beyond what meets the eye

Author(s):

Mostafa Y. Ismail, Mohammad Karzarjeddi, Minna Patanen, Juho Antti Sirviö, Stephen A. Hall, Harri Kosonen, Matti Ristolainen, Henrikki Liimatainen

Corresponding author: Mostafa Y. Ismail

Affiliation: University of Oulu

E-mail: mostafa.ismail@oulu.fi

Abstract:

Lignocellulosic materials are an essential part of the economy, being used in every sector in our daily lives. Lignocellulosic materials—extracted from wood—have a hierarchical structure that gives it remarkable mechanical and physiochemical properties. If employed properly, and with the addition of additives, lignocellulosic materials can have tunable properties that can be used in different applications to replace petroleum-based materials.

We used advanced imaging techniques, such as Scanning transmission X-ray microscopy, to measure the spatial and chemical properties of cellulose nano-fibers (CNF)-silica hybrids. Laser confocal profilometry and X-ray tomography were used to measure the topography and its periodicity of the tissue paper surface, nondestructively. Fluorescence lifetime imaging was used to measure the structural alteration in cellulose fibers after hydrolysis, and to understand the morphological changes. Finally, by adding ionic liquids to CNFs, we managed to develop thermochromic cellulose films that can be used as COVID-19 vaccine label.

Understanding the lignocellulosic materials beyond what meets our eyes will allow for the development of cost-effective, efficient, and biodegradable products, and provide us the ability to modify materials to fit the intended applications.

Key words:

Cellulose fibers, Fluorescence lifetime imaging, Lignocellulose, Laser scanning confocal microscopy, Micro-computed topography, Tissue paper, Thermochromisim

14: Cellulose materials for value-added applications in photonic and electronic devices

Author(s): Aayush Kumar Jaiswal, Ari Hokkanen, Vinay Kumar, Hannes Orelma

Corresponding author: Aayush Kumar Jaiswal

Affiliations: VTT Technical Research Centre of Finland, Åbo Akademi University

E-mail: aayush.jaiswal@vtt.fi        

Abstract:

Lignocellulosic biomass is considered one of the most futuristic and sustainable natural resources due to its abundance and its renewability. The major constituent of biomass, i.e. cellulose finds itself at the crossroads of the development of a bio-based and a circular economy. The bio-based economy concept focuses on the use of renewable, biological materials whereas, the circular economy model emphasizes on complete recycling of products. Cellulose, being a natural, fully biodegradable, and renewable material, fits well in both futuristic economic concepts. However, due to the declining demand for conventional products like pulp and paper, it has become increasingly important to convert biomass into novel products and derive high commercial value from them.

This work focuses on developing high-value applications for cellulose materials in the fields of photonics and electronics. This is achieved via fabrication of films and fibers based on cellulose nanomaterials and cellulose derivatives. Cellulose films are demonstrated for utilization as planar waveguides, as optical modulation films, and as substrates for printing electronic health monitoring devices. In a separate section of the work, optical fibers are fabricated from cellulose derivatives and their application in respiratory rate sensing and broadband signal transmission is demonstrated. Concludingly, this work aims to provide several value-added proof-of-concept applications for cellulose materials that could benefit the forest industry in the future.

Key words:

cellulose, films, fibres, optoelectronics, printed electronics, photonics, bioeconomy, circular economy

15: Drying oils for the preparation of superhydrophobic wood surfaces

Author(s): Jan Janesch, Christian Hansmann, Wolfgang Gindl-Altmutter

Corresponding author: Jan Janesch

Affiliation: BOKU – University of Natural Resources and Life Sciences Vienna and Wood K plus

E-mail: j.janesch@wood-kplus.at        

Abstract:

The high interaction of wood with water gives rise to several problems such as dimensional instability, fungal decay and ultimately a decline of the mechanical properties. Drying oils and natural waxes are environmentally benign and have a long tradition in the hydrophobic treatment of wood. Several recent works describe the use of waxes to turn wood surfaces superhydrophobic (water contact angle > 150°) and thereby protect it from water. Because these coatings are generally unstable towards temperature and mechanical abrasion, the aim of this research project is to explore if the use of drying oils could improve the properties of environmentally benign superhydrophobic coatings.

Spruce wood was coated with blends of tung oil and beeswax, and micronized salt particles were deposited onto the liquid coating film. After the autoxidative curing of the tung oil, the salt particles were washed out with water. Their imprints gave rise to a micro-structured surface, which resulted in static water contact angles above 160°. Applying a short heat treatment above the melting point of beeswax proved that higher amounts of tung oil significantly increased the heat stability of the coatings. We further propose that drying oils could increase the mechanical resistance of bio-based superhydrophobic coatings on wood, which will be investigated in future work.

Key words:

Superhydrophobic wood, tung oil, drying oil, beeswax

16: Circular process design, engineering and techno-economic assessment of an advanced regional biomass processing depot

Author(s): Pierre-Olivier Lemire, Francois Labelle, Patrice Mangin, and Simon Barnabé

Corresponding author: Pierre-Olivier Lemire

Affiliation: Innovations Institute in Ecomaterials, Ecoproducts and Ecoenergies (I2E3) – University of Québec in Trois-Rivières (UQTR)

E-mail: Pierre-Olivier.Lemire2@uqtr.ca        

Abstract:

A local circular process of an advanced biomass processing depot, including engineering and techno-economic assessment has been designed and applied to a case study in southern Quebec.  The role of the biomass depot and its supply chain is to collect, transport, store, pretreat, and convert biomass into intermediate commodities and final products. The depot converts organic residues, i.e. corn stover and urban organic waste, into 2nd generation sugar, bio-CH4, and co-products. The core business is to produce glucose which is subsequently converted to high-value molecules at the biorefinery. The depot model is operating in symbiosis with a pig farm and an anaerobic digester. The co-products of the corn stover deconstruction is used on-site as animal feed and bioenergy without transportation. The anaerobic digester treats on-site pig manure as substrates supplemented with urban organic waste from local areas. The biogas is upgraded, compressed, and distributed, in the form of bio-CNG (compressed natural gas) to supply the depot transport operations and other local transport usages. The model considers technical aspects (mass, energy and water balance, GHG emissions) and economic aspects (OPEX, CAPEX, revenues, and minimum sugar selling price). A sensitivity analysis has been performed to indicate the influence of the various parameters.

Key words:

Circular economy; Industrial ecology; Biomass processing depot; Agricultural waste; Municipal organic waste; Techno-economic assessment; Energy return on investment (EROI); 2nd generation sugars; Bio-CH4; Co-products valorization

17: Capturing nano- and microplastic particles with nanocellulose networks

Author(s): Ilona Leppänen, Timo Lappalainen, Tia Lohtander, Christopher Jonkergouw, Suvi Arola and Tekla Tammelin

Corresponding author: Tekla Tammelin

Affiliation: VTT Technical Research Centre of Finland

E-mail: ilona.leppanen@vtt.fi

Abstract:

Microplastic pollution entering our environment at an increasing rate is a major problem. Owing to the limited degradability of plastic particles, they have been shown to accumulate in various aquatic environments. Especially the nanoplastic particles (size <1µm) are considered very harmful to the environment due to their small size, large surface area, and colloidal nature. To date there are no means to recover nanoplastics from the environment since existing methods are suited only for the larger microplastic particles (>50µm). These restrictions leave a blind spot for the recovery, quantification and qualification of the most harmful fraction of nanosized plastic particles.

Here we show how we have been able to bridge this significant methodological gap by utilizing wood-derived nanocellulose. We have discovered that an extremely hygroscopic and nanoporous network formed by cellulose nanofibrils (CNFs) acts as an ideal capturing element for colloidal sized nano- and microplastic particles. These hygroscopic nanocellulose assemblies display unique water transport properties involving capillary action and diffusion, which are able to transport the particles into the structure. To demonstrate the viability of nanocellulosic networks in micro- and nanoplastic recovery and capturing, we utilised model plastic particles with defined surface charge and size distributions, i.e. anionic and cationic microsized particles (ø = 1.0 µm) and nanosized particles (ø = 100 nm). Nanocellulose hydrogels and dense 2D self-standing films were used as capturing substrates and the accumulation of particles was verified using fluorescence methods. In addition, we have used a quantitative approach by which we are able to calculate precise amounts of particles captured by cellulosic films but also gain information on the phenomena dictating the capturing process. In this complex problem, a natural material offering several types of interaction shows potential that can be developed into solutions for capturing the most harmful and invisible part of the microplastic problem. 

Key words:

nanocellulose, microplastics, nanoplastics, hygroscopicity, capture

18: Neutron scattering study on the structural evolutions of PCL grafted holocellulose

Author(s): Lengwan Li

Corresponding author: Lengwan Li

Affiliation: WWSC, Fiber and polymer Technology, KTH Royal Institute of Technology

E-mail: lengwan@kth.se        

Abstract:

The wood structure consists of cellulose, hemicellulose and lignin assembled in a hierarchical architecture with the cell wall as a nanostructured high-strength composite. The peracetic acid delignification process and ɛ-caprolactone (ɛ-CL) grafting inside the cell wall creates an interesting but complex system. The considered factors include wood species differences, anisotropic structure, swelling effects, and surface hydroxyl influenced by solvents. ɛ-CL grafting creates a spatial distribution in the cell wall, which makes the structure difficult to be characterized by classical tools such as TEM, AFM or NMR.

Neutron scattering combined with deuterated components provide a facile way to address the localization of PCL by matching hemicellulose with cellulose and using fully deuterated or fully hydrogenated PCL, When PCL is matched with deuterated hemicellulose, we isolate the spatial distribution of crystalline fibril, and finally matching PCL to cellulose and using deuterated hemicellulose allow us to see the spatial arrangement of hemicellulose. The deuteration of hemicellulose are achieved by soaking the sample in heavy water, or D2O/H2O mixture that can be kept in absence to contact with protic solvent. The ɛ-CL and poly-CL are deuterated to target SLD by mixing deuterated and hydrogenated monomers. We captured the dynamics of wood fibers during peracetic acid delignification and the spatial distribution of ɛ-CL grafted molecules. Such structural study is crucial for rational improvement of the processes to make wood fiber-based nanocomposites.

Key words:

Deuteration, Neutron scattering, Holocellulose, ɛ-caprolactone

19: New Strategies to Improve Crop Drought Tolerance

Author(s): Eduardo Mateo-Bonmati

Corresponding author: Eduardo Mateo-Bonmati

Affiliation: Swedish University of Agricultural Sciences

E-mail: eduardo.mateo.bonmati@slu.se        

Abstract:

Agriculture and forestry provide the world’s growing population with food, energy and biomaterials. However, the ongoing climate threat will create frequent events of long dry spells and intense water shortages. Therefore, plant biotechnology is prompted to develop new varieties to produce more with less water. Water scarcity drives root system architecture modifications to enhance its ability to absorb water. This developmental plasticity is operated by the phytohormone auxin, whose role in drought tolerance has been suggested but remains largely unclear. My research aims to decipher the role of genes involved in auxin inactivation in drought tolerance. To circumvent the large plant genetic redundancy, I am obtaining high-order mutant combination employing the CRISPR/Cas9 gene-editing technology. I will deeply analyse their expression dynamics under drought treatments, and I will define the existing hormonal landscape by using fluorescent reporters and hormonal profiling approaches. How these mutations affect to the root system architecture will be analysed both in vitro, by acquiring time-lapse images, and in soil by X-ray microscale computed-tomography and 3D reconstruction. All information gained from genetic, epigenetic, hormonal and phenotypic studies will be used to obtain mathematical models that will pave the way to scale-up our findings to be used in crops.

Key words:

Root architecture, auxin, drought

20: Lessons learned from the implementation of a lianescent plant functional type into a dynamic global vegetation model

Author(s): Félicien Meunier, Marcos Longo, Michael Dietze, and Hans Verbeeck

Corresponding author: Félicien Meunier

Affiliation: CAVELab, Ghent University

E-mail: felicien.meunier@ugent.be        

Abstract:

Despite their low contribution to forest carbon stocks, lianas (woody vines) play an important role in the dynamics of tropical forests where they act as structural parasites and compete with free-standing plants for below- and above-ground resources. Lianas were shown to negatively impact individual tree growth, as well as the forest-scale net productivity and the long-term carbon storage of the ecosystem they infest. However, lianas remain largely ignored in plot-scale ecological studies.

To better estimate the contribution of lianas to forest biogeochemical cycles, we built for the very first time a mechanistic representation of the lianescent growth form in a dynamic global vegetation model (the ecosystem demography model, version 2). In order to account for the functional and structural differences between lianas and trees, we implemented several liana-specific processes (e.g., climbing, resprouting) and integrated multiple liana-specific parameters into the modelling framework, according to data from multiple studies.

Model simulations in various Neotropical sites characterized by different rainfall regimes and levels of liana abundance successfully reproduced ecosystem gas exchange fluxes (GPP and latent heat), forest structural features (e.g. LAI, AGB), and multiple other benchmarking features of the simulated ecosystem and of the liana-tree interactions. In those simulations, lianas negatively reduced forest productivity and total carbon storage, by increasing tree mortality (+ 30% on average) and decreasing individual tree growth (-35%). The inclusion of lianas in the simulations reduced the forest net productivity by up to 0.5 tC ha-1 year-1. Taking lianas into account resulted in significantly reduced above‐ground biomass by up to 20 tC ha -1 in regrowth forests. The negative impact of lianas on carbon storage almost disappeared in wetter, old-growth, aseasonal forest sites. Model simulations also confirmed in silico that liana removal had a significant positive impact on forest carbon storage both below- and above-ground (+20 tC ha-1 in total after 10 years in liana removal plots, as compared to the control plots). Finally, radiative transfer model simulations illustrated the impact of liana-specific optical traits on the energy balance of tropical forests: leaf traits make the lianas very efficient at light interception and increase forest albedo (+14% in the shortwave) while reducing light availability in the understory (-30% of the PAR radiation).

Key words:

Lianas, Tropical forests, Dynamic Global Vegetation Model, Ecosystem Demography model, version 2 (ED2)

21: Are mixed forests more vulnerable to fire damage?

Author(s): Marina PERIS-LLOPIS, Blas MOLA-YUDEGO, Frank BERNINGER, Jordi GARCIA-GONZALO, José Ramón GONZÁLEZ-OLABARRIA

Corresponding author: Marina Peris Llopis

Affiliation: University of Eastern Finland, School of Forest Sciences

E-mail: marina.peris.llopis@uef.fi

Abstract:

Fires damage forests at different levels, modifying the existent landscapes and causing ecological and socioeconomic losses. Spain presents complex landscapes that host diverse forests with numerous species mixtures. The study aims to highlight the influence of morphological traits in the survival of tree species in burned areas and to assess the effect of species mixture in stand damage due to fire. Data are retrieved from the Spanish National Forest Inventory (SNFI) and data concerning morphological traits. The model analyses fire stand damage and tree mortality considering stand structure and topography. The species composition in the burnt SNFI plots is analysed to identify fire damage patterns related to present species mixtures and their traits. The study seeks to identify the effect of present species and their traits on tree resistance and the influence of species mixture on modifying stand level vulnerability. The proposed methods can be used as a tool for forest planning at different levels. The results will help identify resistant landscapes with forests that due to the species mixture and species adaptations among others, will mitigate the impact of fire.

Key words:

fire damage, traits, species mixture, tree mortality, stand vulnerability

22: Cellulose networks in polymer composites: Utilizing nanocellulose to form thermoset-likem yet recyclable materials

Author(s): Anna Peterson, Manta Roy, Massimiliano Mauri, Aleksandar Mehandiyski, Giada Lo Re, Christian Muller

Corresponding author: Anna Peterson

Affiliation: RISE

E-mail: anna.peterson@ri.se        

Abstract:

The research deals with how composites of plastics and cellulose nanomaterials may be produced in a way that allows network formation between the cellulose species. The obtained composites resist creep, even at elevated temperatures, but also is recyclable, a rare material combination. These materials could potentially replace thermosetting plastics for some applications. Further, the impact of cellulose network formation on the stiffness of composite materials is studied. Additionally, composites containing not only a nanocellulose network but also a second network based on reversible covalent bonds is studied, which increase the temperature region in which the material may resist deformation without affecting its recyclability.

Key words:

cellulose nanomaterials, network formation, recyclability

23: Novel production process for softwood-based phytosterols

Author(s): Paula Rantamäki, Pekka Oinas, Marjatta Louhi-Kultanen

Corresponding author: Paula Rantamäki

Affiliation: Aalto University, Stora Enso Biomaterials

E-mail: paula.k.rantamaki@aalto.fi        

Abstract:

The novel phytosterol extraction concept creates added-value for softwood-based tall oil producers. Wood based phytosterols are produced from crude tall oil (CTO), which is a by-product from kraft pulping process (produced ca. 20-50 kg/ADt produced pulp). The phytosterol content of CTO is e.g., 3-4 %, the major components being fatty and resin acids. Today, more than 50 % of the valuable phytosterols from CTO are lost in the phytosterol production process, which is lengthy, energy intensive, costly and has a notable environmental impact.

The technology under development separates phytosterols from the CTO under mild conditions, improving thus the final phytosterol product quality and yield. In addition, the remaining phytosterol depleted CTO has improved quality for further processing. The novel technology provides potentially environmentally sound and economically feasible concept to produce phytosterols, which can be utilized in food, pharma and cosmetic sectors. As the markets for phytosterols are steadily growing (CAGR 9 %) the total business being today > $700 million, there is a great business potential to increase the wood based phytosterol market share.

Our research at Aalto University focuses on the development of phytosterol purification process from a crude phytosterol rich stream. The development of analytical capabilities is essential to guarantee that the final products meet food-grade specifications. After the process concept has been developed, process design and optimization by process simulation software will follow. Finally, overall techno-economic feasibility of the process and sustainability impacts will be evaluated.

Key words:

Crude tall oil, phytosterols, process design, process modeling, techno-economy, sustainability

24: Greening fossil-based bitumen with integration of renewable stabilized pyrolytic oils

Author(s): Olivier Rezazgui, Clément Villemont, and Patrice Mangin

Corresponding author: Olivier Rezazgui

Affiliation: Innovations Institute in Ecomaterials, Ecoproducts and Ecoenergies (I2E3) -University of Québec in Trois-Rivières (UQTR)

E-mail: Olivier.Rezazgui@uqtr.ca        

Abstract:

Pyrolytic oil produced from flash pyrolysis of lignocellulosic biomass presents interesting energetic and physicochemical properties.  Although intensively studied in the literature, it remains of limited use in the industry as it suffers from several major disadvantages (e.g. stability, acidity).

Within an industry collaborative research project, we developed a process for stabilizing and upgrading pyrolytic oils making them suitable for integration in bitumen as a substitute for petroleum products. A one-step esterification procedure using green and inexpensive reagents has been developed up to pilot scale as to be easily transposable to industry.  It implies the reuse of the reaction solvents, either ethanol or butanol. The modified oils show promising physicochemical properties such as high hydrophobicity, an essential element for bitumen integration. A method for evaluating the stability of the modified oils over various periods of time through different parameters was also developed.  A techno-economic evaluation of the proposed process confirmed its industry potential. 

Using forestry residues as prime biomass, the production of such upgraded pyrolytic oil represents a low environmental impact and a renewable solution to replace petroleum-based compounds in the bitumen industry.  It provides new value-added avenues for forestry biomass for the establishment of a sustainable circular economy.

Key words:

Pyrolytic oils, lignocellulosic biomass, forest residues, bitumen

25: Biofuels from forest residues:  optimization and techno-economic study of carbon intensity reduction strategy

Author(s): Patricia Rioux

Corresponding author: Patricia Rioux

Affiliation: Innovations Institute in Ecomaterials, Ecoproducts and Ecoenergies (I2E3) – University of Québec in Trois-Rivières (UQTR)

E-mail: Patricia.rioux@uqtr.ca        

Abstract:

Biomass gasification methods are becoming increasingly popular worldwide as they can be used to convert low-value forest or agricultural residues into biofuels. While several industrial-scale projects are under development, their viability must still be greatly enhanced. In fact, most of the carbon in biomass used for biofuels ends up as CO2 during gasification and is consequently lost. A significant improvement in carbon conversion is possible by adding hydrogen to prevent the loss of carbon or to react directly with CO2 through the reverse water gas shift reaction to produce extensively more syngas. Although considered one of the most efficient and viable pathways to reduce the use of fossil fuels, a reasonably priced hydrogen supply with a minimal environmental footprint still crucial in view of the strict regulations to come.

In this context, the technical, economic and environmental assessment of the B.E.L.T. project – a proposal to convert 650,000 tonnes of forest residues annually into renewable biofuel – is being conducted in line with Canada’s 2030 energy transition. In parallel, we are conducting an in-depth analysis of the potential and economic viability of CCSU (Carbon Capture and Storage and/or Utilization) strategies to significantly reduce the project’s currently high carbon intensity.

Key words:

Biomass, Gasification, Biofuels, Forest residues, Hydrogen, Carbon Capture and Storage and/or Utilization (CCSU)

26: Time dynamic climate impacts of Nordic forest management strategies: Implications for forest product systems and substitution effects from a life cycle perspective

Author(s): Maximilian Schulte, Torun Hammar, Johan Stendahl, Ragnar Jonsson, Per-Anders Hansson

Corresponding author: Maximilian Schulte

Affiliation: Swedish University of Agricultural Sciences

E-mail: maximilian.schulte@slu.se        

Abstract:

Forests sequester and store carbon dioxide (CO2) via photosynthesis in form of biogenic carbon in biomass and as soil organic carbon. Biogenic carbon from forest biomass can be stored in harvested wood products (HWPs) which generally release less fossil greenhouse gas (GHG) emissions compared to functionally equivalent non-wood products, such as concrete or plastic materials. HWPs can thus avoid GHG emissions via substitution effects by displacing non-wood materials, especially when sourced from sustainable forestry. This results in a climate trade-off among biogenic carbon storage in the forest ecosystem, and increased harvests and substitution effects in the technosystem to reach net atmospheric emission reduction.

To analyse these climate mitigation trade-offs more unambiguously, case specific regional-level assessments are needed, integrating the interconnected forest eco- and technosystem plus the substituted system (= system perspective), to avoid conflicting and misleading policy recommendations in order to reach net climate benefits. For this reason the present project provides an integrative time dynamic life cycle assessment (LCA) analysing the climate effects of different forest management strategies from a system perspective based on a Swedish region. The objective is to (1) increase understanding on climate mitigation of forest product systems following alternative forest management strategies, and to ascertain (2) forest management’s influence on substitution effects.

Key words:

Forest Management, Climate Effects, Forest-based Bioeconomy, Nordic Forests, Sweden, Substitution Effects, Life Cycle Assessment

27: Bioactive Surfaces with Cellulose II Nanospheres for Highly Sensitive Immunosensors

Author(s): Katariina Solin, Marco Beaumont, Maryam Borghei, Hannes Orelma, Orlando Rojas

Corresponding author: Orlando Rojas

Affiliation: Aalto University

E-mail: Katariina.solin@aalto.fi

Abstract:

Immunosensors are bioanalytical tools used for the detection of various analytes in epidemic disease control, pharmaceutical, and food industries, as well as in clinical analysis and diagnostics. Recently, in the development of immunosensors, the focus is on the improvement of the immunosensor performance by increasing their specificity and sensitivity. This is especially relevant in the recent times of coronavirus pandemic. To improve analytical performance, one possibility is to use new approaches to improve the immobilization of immunoreagents on the sensor substrates. We have developed a new surface anchor layer that can significantly increase the antibody immobilization capability of surfaces. This bioactive layer is obtained by using cationic cellulose II nanoparticles with an intrinsic hard-core/soft-shell structure that can form protein-accessible, water-swollen assemblies, so-called colloidal nanogel layers, on thin nanocellulose films and paper. We showed that the formed nanogel layer can adsorb about three times the amount of proteins than a conventional polymer-coated surface and that the layer enables specific protein interactions, which are advantageous for diagnostic applications. Our results show the potential of these soft cellulose nanoparticles to develop next-generation cellulose-based immunoassays with significantly higher sensitivity.

Key words: Cellulose Ⅱ nanospheres, bioactive surfaces, protein adsorption, amorphous nanocellulose, soft colloids

28: The application of enzyme-polymerized lignin in fiber product and silver hybrid nanoparticles

Author(s): Luyao Wang, Liqiu Hu, Qingbo Wang, Anna Slita, Jessica M. Rosenholm, Xiaoju Wang, Chunlin Xu

Corresponding author: Chunlin Xu and Xiaoju Wang

Affiliation: Åbo Akademi University

E-mail: luwang@abo.fi

Abstract:

Enzymatic treatment is an environmentally benign and sustainable method in the valorization of technical lignins that are derived from pulping and biorefinery industries. Recently, a new genetically evolved bacterial laccase (commercialized as MetZyme® product) was reported to efficiently oxidize hardwood mild acidolysis lignin under highly alkaline conditions (pH 10.5). This alkaliphilic laccase was further applied in the current study. Both hardwood and softwood alkaline lignin (ALs) were fractionated by alcohols with gradient polarity to derive fractions with well-defined characteristics. These fractions were then polymerized by laccase at pH 10. The correlations between lignin structural characteristics and laccase-assisted lignin oxidation/polymerization performance were investigated. We further extended the study to in situ laccase polymerization of ALs fractions with the dispersed microfibrillated cellulose (MFC) present as a structural template. Both the morphology of the lignin-coated MFC in the dispersions and the nanocomposite film properties prepared by vacuum filtration of the as-synthesized dispersions were characterized. The laccase-polymerized lignin also exhibits higher thermal stability and chemical tolerance than the initial counterparts. It facilitated the formation of alkali-resistant lignin nanoparticles (LNP) which possessed durable dispersity and functionality under high pHs and in certain organic solvents. Therefore, it allowed the efficiently chemical integration of the alkali-resistant LNP in in situ reduction of silver nanoparticles from silver ammonia solution (pH 11). This study demonstrates a green approach in utilizing lignin in fiber-based packaging and also as nanocomposites in harsh conditions.

Key words:

Alkaliphilic laccase, Lignin polymerization, Packaging, Hybrid nanoparticles, Green Chemistry

29: Interactions between Cells and Bio-based materials: from Quantitative Analysis to 3D-printed Scaffolds for Medical Applications

Author(s): Xue Zhang, Juan José Valle-Delgado, Monika Österberg

Corresponding author: Monika Österberg

Affiliation: Åbo Akademi University

E-mail: xue.zhang@abo.fi

Abstract:

There is a continue demand on developing the three-dimension (3D) cell culture models to release organ crisis issue and eliminate using animal models. Tissue engineering, an interdisciplinary field, involving cell biology, engineering and materials science, aiming at repairing or replacing biological tissues, can provide a solution. Cell behavior like cell viability, proliferation, migration, and differentiation strongly depend on the cell interactions with the surrounding materials both in vivo and in vitro. In vivo, cells are embedded in the extracellular matrix (ECM), a complex 3D network with components secreted by the resident cells. The use of biomaterials mimicking ECM can offer better performance for tissue engineering applications. The ideal biodegradability and biocompatible natural polymers hydrogels, especially plant-based animal-free cellulose nanofibrils (CNF) are sustainable, economic and sustainable options for biomedical application.

In my research, the interactions between plant-derived CNF and human living cells were studied by AFM-based colloidal probe microscopy in combination of surface plasmon resonance technique. Based on the theoretical results, 3D printed CNF-based scaffolds with high water retention capability, mechanical stable and tunable stiffness were successfully developed based on these fundamental knowledges.

Key words:

Interactions, cellulose nanofibrils, living cells, atomic force spectroscopy, surface plasmon resonance, 3D scaffolds