[dipl] Kemian tekniikan korkeakoulu / CHEM

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    The costs of single-use consumer packaging
    (2024-01-23) Hart, Janika; Lahtinen, Jussi; Kemian tekniikan korkeakoulu; Paltakari, Jouni
    The price of a fast-moving consumer good (FMCG) includes the costs of its packaging which are made up of multiple different costs throughout the packaging supply chain and life cycle, from production to use to disposal. Some of these costs are initially covered by fees to companies with producer responsibility, but most packaging related costs are paid for by consumers when they buy a packaged product, when they pay residential waste fees and through taxes. Since these costs are spread throughout the supply chain, the total amount of packaging related costs per product are not well known, especially by consumers. The literature review explains the background to single use, legislation related to packaging and packaging waste, producer responsibility and municipal waste management of packaging. To gain further knowledge and understanding on the costs of single-use packaging in Finland and make these costs more visible to consumers, relevant stakeholders in the packaging supply chain were interviewed. These included brand owners, waste management organisations and other relevant organisations. The interviews were held as in-depth interviews, where interviewees were asked about topics that were predetermined to be possible factors to packaging related costs of the organisation types. The interviews aimed to explore the causes, development, and future trends of these costs, as well as their impact on the organisations and costs to consumers. Additionally, information related to costs was gathered from literature and cost calculations were done to estimate packaging related costs of packaging case examples and residential waste fees around Finland. Based on the stakeholder interviews, it was concluded that in recent years, there has been a substantial increase in packaging related costs, such as producer responsibility fees and costs of waste management. These costs will continue to increase, as legislation is updated, and more requirements are added. The recent changes in EU legislation that have brought costs to brand owners and waste management, are increasingly complex reporting requirements of packaging put on the market and higher recycling targets causing additional costs due to the need to expand the separate collection of packaging. As the EU is aiming for a transition to a circular economy, and the single use system and its costs are changing, it could be considered, if in some situations reuse can be a cheaper alternative to single use.
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    Synthesis and characterizations of chromium doped Fe3Se4: Magnetic and electronic transport properties
    (2024-01-23) Pham, Trang; Tewari, Girish; Kemian tekniikan korkeakoulu; Karppinen, Maarit
    This study investigates chromium(Cr)-doped Fe₃Se₄, revealing complex interactions between crystal structure modification and magnetic/electronic behaviors. The solid-state synthesis of Fe₃Se₄ confirms its monoclinic structure (I2/m). Cr doping induces significant shifts in XRD patterns, indicating alterations to the lattice structure and effective Cr integration in the chemical formula (Fe1-xCrx)3Se4. The coexistence of monoclinic phases I2/m and C2/m indicates polymorphism, offering insights into structural changes during Cr doping. Magnetic property analysis shows the ferrimagnetic behavior of undoped Fe₃Se₄ with a Curie temperature of 325 K. Cr doping results in diverse magnetic responses, including reductions of Curie temperature at x = 0.1 and transformations to hard magnetic properties. The x = 0.1 doping level emerges as a promising candidate for tuning magnetic properties. Resistivity analysis explores electronic transport, highlighting temperature-dependent variations in Cr-doped samples compared to the undoped Fe3Se4 sample. The intricate influence of Cr doping on electronic properties, linked to crystal structure anisotropy modifications, is also clarified in this study.
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    Strep-tag based method for protein quantification
    (2024-01-23) Kotovuori, Tomi; Malkamäki, Maaria; Kemian tekniikan korkeakoulu; Linder, Markus
    Protein quantification is the base for protein analysis. As understanding of proteins is essential in numerous different fields, they are heavily studied. There are a lot of different quantification methods that either analyse the total protein or a specific protein content of a sample. However, no method is suitable for all types of protein samples, as each assay has their own requirements, advantages and challenges. This thesis focuses on the quantification of a specific protein using a peptide tag called Strep-tag. This new form of protein quantification is based on a western blot assay coupled with radioactive detection and it has been tested with silk-like proteins. The silk-like recombinant proteins containing a Strep-tag in their N-terminus were expressed in Escherichia coli. They were purified using affinity chromatography and quantified using Strep-Tactin, a ligand, which binds specifically and with high affinity to a Strep-tag present in studied proteins. Strep-Tactin has been modified to contain a radioactive tritium label, the decay of which is measured at the final stage of the assay using liquid scintillation counting. The radioactivity measured is proportional to the protein concentration of the sample. The aim of this thesis was to improve and optimize this method, as it was relatively new. In addition to making sure the protocol steps worked as intended, protein detection limits were determined and different forms of Strep-tags and Strep-Tactins were compared to find the superior combination. This quantification method has shown great potential by producing results with high accuracy faster than other common methods in the field.
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    Solid-state batteries for electromobility applications – Towards market integration by 2030, through Horizon Europe funding program.
    (2024-01-23) Hendrickx, Pierre; Michel, Camille; Kemian tekniikan korkeakoulu; Karttunen, Antti
    In the context of decarbonisation of Europe by 2050, solutions need to be developed to accommodate our society to less dependency on fossil fuels energy, especially in the transportation sector. Innovative batteries have been at the core of research for electromobility applications. This thesis considers the most advanced ones at this stage: Solid-state batteries. Several materials for anode, cathode and electrolyte have been reviewed and strategic choices have been made to build a project answering an example of Horizon Europe call, namely “Advanced materials and cells development enabling large-scale production of Gen4 solid-state batteries for mobility applications”. Additional expertise needed to answer this call have been highlighted and strategies towards maximising such a project’s impacts (through exploitation and communication strategies) have been drafted. Overall, this thesis provides a comprehensive path to commercialisation for solid-state batteries in the transportation sector, through European fundings.
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    Numerical simulation of fire resistance tests of stone wool under different fire scenarios
    (2024-01-23) Coudé du foresto, Victoria; Troudet, Estelle; Kemian tekniikan korkeakoulu; Hostikka, Simo
    Fire safety engineering is a critical aspect of building design, particularly as traditional approaches based on standardized conditions may not fully capture the dynamic nature of real-world fire scenarios. This research focuses on the impact of temperature-dependent material properties, specifically thermal conductivity, on fire conditions modelling, with an emphasis on rock wool panels used for HVAC duct protection. The study aims to enhance the accuracy of fire resistance assessments by incorporating temperature sensitivity into models and optimizing rock wool panel thickness under standardized fire conditions. Hypotheses suggest that considering temperature-dependent properties will reveal significant differences in thermal behaviours, and optimizing panel thickness can provide insights into performance-based design. The study introduces a simplified numerical model and emphasizes the importance of diverse fire scenarios in designing fire protection systems. While economic advantages can be gained through parameter adjustments, the study calls for more sophisticated models to further enhance results and explores a range of optimization possibilities for fire protection systems.
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    Industrial-scale microwave heating of waste oils and fats – Technology evaluation
    (2024-01-23) Kostiander, Niilo; Hommes, Arne; Turkka, Jyri; Kemian tekniikan korkeakoulu; Oinas, Pekka
    Research of renewable energy technologies has gained increasing amount of interest in recent years. Microwave (MW) heating has been found to have benefits in a wide range of fields and it has successfully replaced conventional heating methods in many applications, such as food, polymer and ceramics processing. With the technology, notable reductions in processing time, fouling and greenhouse gas emissions have been achieved. However, widespread use of microwaves in industrial scale has not yet taken place. The aim of this thesis is to provide a general view on the feasibility of microwave technology in heating waste oils and fats in hydrotreated vegetable oil (HVO) pre-treatment process. Waste lipid feedstocks tend to form solid particles on the walls of conventional heat exchangers in high temperatures. MW heating, with its unique heating mechanism, could possibly address this problem by eliminating the hot surfaces of the equipment and hence reduce fouling. This would cause less downtime of the plant increasing the annual production capacity. The general advantages of MW heating are rapid heating with minimal heat gradient and possible enhanced reaction rates. The disadvantages are difficult scale-up and possible increased side-reactions. In the literature study, it is concluded that oils and fats can be effectively heated because of their low specific heat capacity and high penetration depth of microwave irradiation. Moreover, some promising laboratory results have been published about MW processing of lipids; the irradiation has been found to enhance bleaching and degumming of oils. In the applied part, the technical feasibility and costs of microwave heating are assessed, using an example design case from the HVO pre-treatment process. In the example case, a process stream of 160 t/h is heated from 160 ℃ to 280 ℃ with MW irradiation. Based on the results, it is challenging to feasibly apply microwave heating in industrial-scale heating of waste oils and fats. The limited capacity of a single microwave heater increases the required number of modules (16), resulting in high investment costs (65 M€) and large physical area (837 m2) needed. The annual energy costs are estimated to be 20 M€. The high operating costs (26 M€) are caused by the low energy efficiency of microwave heaters (55%) as well as relatively high maintenance costs (6 M€/a) due to the yearly requirement to replace the MW generators. The main challenges of MW heaters are low energy efficiency and flow capacity. Microwave heating needs to significantly reduce fouling or offer some other benefit in HVO pre-treatment performance to compensate for the disadvantages. Further development of scaling up the technology is needed and more studies on heating waste oils and fats with microwaves should be conducted.
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    Utilization of future food court side streams as alternative carbon and nutrient source for plant cell cultures
    (2024-01-22) Lillberg, Amanda; Ritala, Anneli; Pajumo, Maria; Kemian tekniikan korkeakoulu; Jouhten, Paula
    Current food production capacity with only conventional agriculture is not sufficient to solely sustain the food demand for increasing human population. Sufficient food production could be enabled by combining conventional farming with cellular agriculture. Cellular agriculture refers to the production of agricultural commodities with plant, microbial and animal cells. Cellular agriculture, such as single cell protein synthesis, could also reduce the food production associated burden to land use and climate of food in the future. However, applications in cellular agriculture comes with many challenges, one of which includes the high costs for growth medium components. The aim of this thesis was to utilize alternative sources for carbon and nutrients for the plant cell growth medium to reduce costs. The alternative sources assessed in this thesis included biodegradable side streams from shopping centre environment. There, side streams accumulate from food courts and markets and could include orange peels, soda drink waste mix, expired bread, spent coffee grounds and brewer’s spent grains. Urine was also considered as a potential nutrient source since it possesses many valuable compounds that are required for the growth of plant cells. Future efficient purification technologies could permit the food regulation to allow the use of urine as a nutrient source. Plant cells require carbon and nutrients in a soluble form, therefore pre-treatments were applied for solid side streams to release monosaccharides from longer polysaccharide chains. The utilization potential of the side streams was evaluated by using them as culture medium components for cultivations of three non-taxonomically related plant cell lines: arctic bramble, tobacco BY-2, and barley. The side stream suitability was assessed by using biomass production after a cultivation period as a scale for comparison. Soda drink waste mix and synthetic urine contributed for the highest biomass concentrations, which was used as a measure for growth. These side streams were used as main components for optimization of growth media composition. Both side streams were successfully utilized for cultivations, especially for arctic bramble with notable increase in biomass concentration. Side streams were found to be potential culture medium components for plant cell cultures but notable differences in growth and growth behaviour between the studied plant cell lines were observed. The appliance of thus far unutilized side steams would enhance the circular economy and improve the food value chain. In addition, the economical sustainability of production would improve as costly components would be replaced with unutilized sources.
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    Reactivity in organic precursors in atomic/molecular layer deposition
    (2024-01-23) Partanen, Olga; Jussila, Topias; Kemian tekniikan korkeakoulu; Karppinen, Maarit
    The modern era constantly requires thinner and more complex materials. A combined atomic and molecular layer deposition (ALD/MLD) is a versatile technique for depositing extremely thin but functional films. ALD/MLD has attracted interest due to the possibility to deposit high-quality inorganic-organic hybrid thin films with mixed properties from both inorganic and organic parts of the thin film. The organic parts of the ALD/MLD hybrid thin films can enhance a great number of properties such as flexibility and electric effects. Although most of the research focuses on developing novel ALD/MLD processes and characterizing the material properties, it is needed to consider how the reactivity of precursor compounds affect the growth and stability of the thin film. In this thesis, reactivity of organic materials is reviewed to investigate which makes organic compound reactive and how does reactivity affect the stability of the thin film. In this thesis, five inorganic-organic hybrid materials were fabricated by ALD/MLD. Four of them were completely novel: Co-BDT, Co-HQ, Fe-ADN, and Fe-ADH. For broader study about the reactivity and stability of different organic compounds, also Co-TPA thin films were deposited. The processes were developed, and the thin films were characterized with various characterizing methods. Lastly, the reactivity and stability of thin films were analysed on the perspective of the film growth and aging stability. The Co-based materials deposited in this thesis yielded high-quality hybrid thin films. Fabrication of the Fe-based materials turned out to be more challenging: Neither of the Fe-based materials showed saturation, and precursors might not have reacted fully. However, Fe-ADH showed interestingly crystalline structure which attracts further interest on the material. Additionally, further research and development of novel ALD/MLD hybrid thin films is needed for better understanding of reactivity and its effects on thin films.
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    Co-precipitation of Ni0.8Mn0.1Co0.1(OH)2 with a draft tube reactor
    (2024-01-23) Lepistö, Riikka; Aromaa, Jari; Koponen, Markus; Kemian tekniikan korkeakoulu; Lundström, Mari
    As the world moves towards cleaner and more sustainable energy solutions, the demand for lithium-ion batteries (LiBs) has surged due to their conclusive role in powering of electric vehicles (EVs), renewable energy systems, and portable electronic devices. Cathode active materials (CAMs) are the key components of LiBs since they have a vital effect on the overall performance of the battery. Different types of CAMs exhibit varying properties, such as energy density, power output, and lifespan. Preparation of CAM typically involves the synthesis of their precursors (pCAMs) via co-precipitation, followed by calcination with lithium salts. Producing of appropriate precursors is crucial as it influences the electrochemical performance of the resulting CAM. However, obtaining battery-grade pCAM is known to be challenging due to the sensitivity of the precipitation process and due to the several key characteristics of the product, such as particle mean size, morphology, and density, thus, more research on pCAM synthesis was needed. In this study, the most common CAMs were investigated to find out the most desirable state-of-the-art cathode chemistry for its pCAM synthesis. Nickel-rich precursor of LiNiMnCoO2 (NMC811) was chosen as the target chemistry due to its high energy density, good cyclability, and low cobalt content. Furthermore, the battery graded NMC811 precursor characteristics were explained as well as how the operational factors influence on the product quality. Factors affecting fluid motion, such as stirring speed, impeller type and reactor configuration, are one of the operating parameters that have an impact on particle size, shape and density of the pCAM product. As a part of Metso’s Precursor Development project, a draft tube circulator mounted inside a laboratory scale reactor was examined to see if it was possible to obtain battery grade pCAM. Draft tubes are known to improve fluid motion and hence the dispersion of the particles. The study showed that it can be possible to produce NMC811 precursors with good quality. In addition, four different impeller systems were studied among with different mixing velocities. Single axial impeller system at high stirring speed resulted in dense and spherical pCAM product with relatively low agitation duty.
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    Validation of an assay for protein quantification using tritium detection
    (2024-01-22) Niskanen, Linnea; Malkamäki, Maaria; Gandier, Julie-Anne; Kemian tekniikan korkeakoulu; Linder, Markus
    Validation of a new analytical method is done to estimate its fit for purpose prior taking the method as part of routine analyses of the laboratory. In method validation series of predefined experiments are done to determine values for chosen validation characteristics. With statistical tests it is possible to identify the parts of the assay that affect to the reliability of the assay. Different regulatory bodies give varying recommendations for validation procedure and different definitions of terminology may lead to misinterpretations and wrong conclusions. The aim of this work was to improve and validate a novelty protein quantification method, that is based on detecting tritium labelled ligand, StrepTactin-XT from protein sample. StrepTactin-XT binds specifically to Twin-Strep-tag. In this assay the Twin-Strep-tag is coded into N-terminal of the protein of interest, silk protein CBM-AQ12-CBM. The aim was to validate the methods suitability for its intended purpose and to determine linearity of calibration curve, limit of detection (LOD), limit of quantification (LOQ), accuracy and precision. The validation procedure was planned following recommendations of accredited validation organizations, but also taking into account the limitations that were set by the properties of the assay. The linear range of the assay was analysed using Fisher variance ratio and it was set to cover 6-350 ng. LOD and LOQ were determined using signal-to-noise relationship, and they were set to 6 ng and 13 ng, respectively. Relative error had variance between 0,3-70 %, making the average accuracy to be 78 %. For precision, the repeatability was on average 95 %, but due to limited time there was no possibility to measure intermediate precision.
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    Comparative analysis of dyeing behaviour of cellulose and regenerated cellulose in solvent-assisted salt-free reactive dyeing
    (2024-01-23) Dutta, Shubhajit; Periyasamy, Aravin Prince; Kemian tekniikan korkeakoulu; Tehrani, Ali
    This research aimed to investigate the viability of a solvent-assisted salt-free reactive dyeing method for cellulose & and regenerated cellulose using reactive dyes without adding salt and employing solvents, such as EtOH, IPA, and PrOH as alternatives to conventional dyeing. Eight different reactive dyes with distinct reactive groups were involved in this study. The study focused on assessing the color strength, dye exhaustion, fixation, and colorfastness properties of cotton and viscose fibers and how and why they change their dyeing behavior in different reactive dyes in several solvents. It was found that reactive dyes were less soluble in alcohol due to the polarity of the solvents and sulfonate groups in their chemical structure than in water. Moreover, the porosity and the crystallinity of the fibers have been investigated to understand the dyeing characteristics of the fibers. On average, the K/S values of viscose fabrics dyed with the conventional dyeing method were approximately three times higher than those values on cotton fabrics due to having a more porous and less crystalline area than cotton. In contrast, due to the reactive dye hydrolysis in alcohols being expected to be less than that in water, reactive dyes could not make enough covalent bonds with cotton or viscose fiber as in water. The exhaustion of reactive dyes on cotton had overall higher exhaustion%, and fixation% in alcohol than viscose compared to conventional dyeing. Contrarily, viscose fibers, as being man-made and chemically processed, exhibited lower exhaustion%, and fixation% in comparison. Furthermore, substituting water with solvents did not compromise the fabric's wash, rub, and light-fastness properties, which remained the same. It can be concluded that solvent-assisted salt-free dyeing performed better in comparison to conventional dyeing for cotton with reactive dyes rather than viscose.
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    Set-up and incorporation of a nucleic acid purification protocol in a PCR based diagnostic test for respiratory pathogens
    (2024-01-23) Boström, Sanna; Hokynar, Kati; Piilola (Piitulainen), Hanna; Kemian tekniikan korkeakoulu; Linder, Markus
    Respiratory tract infections are prevalent worldwide, and their mortality rates are generally low in individuals with good health. However, such infections can be severe and sometimes fatal, especially among young children, the elderly, and immunocompromised people. Especially with severe infections fast and reliable diagnosis is crucial. Traditional diagnostic methods for respiratory pathogens, e.g., culturing, are time-consuming and laborious. Molecular diagnostic methods, such as nucleic acid amplification-based tests have revolutionized the diagnostics of respiratory tract infections and are now the golden standard method. The aim of this thesis is to develop and optimize a nucleic acid extraction protocol for a prototype diagnostic test on Novodiag® system detecting respiratory pathogens and to evaluate the efficacy of the developed extraction method. Novodiag® is a rapid molecular diagnostic test for detecting infectious agents and antibiotic resistance developed by Mobidiag. The study started by examination of extraction efficacy of different silica types with both DNA and RNA targets. Next phase included optimization of the binding buffer. Finally, the sample preparation method was integrated into Novodiag® cartridge and its performance was studied by comparing automated Novodiag® extractions to manual version and to a reference method. This thesis led to the discovery of a novel alternative silica that not only matched the performance of the standard silica but also surpassed it when targeting RNA. Optimization of the binding buffer for RNA targets was successful, and the sensitivity increased up to 100-fold compared to the original binding buffer. However, the new optimized binding buffer did not reach the sensitivity of the reference method but was decreased 10-fold compared to easyMAG®. The integration of sample preparation method to the Novodiag® was successful, but evaluation of extraction efficacy showed approximately a 10-fold decrease in sensitivity compared to manual nucleic acid extraction. Based on the results of this thesis, silica examination should be further studied, especially with both DNA and RNA targets and also in the presence of clinical sample matrix. In addition, sample preparation protocol in Novodiag® should be further optimized to reach the same or better performance and sensitivity as in manual nucleic acid extraction.
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    Quality assessment of wood recovered from building demolition
    (2024-01-23) Roy, Satyaki; Nasiri, Bahareh; Kemian tekniikan korkeakoulu; Hughes, Mark
    Wood is an important resource for the construction of buildings and though renewable, has limited stocks in nature. The recycling and reuse of recovered wood has gained significant attention as society seeks sustainable solutions for waste management. Solutions related to better product design and optimized collection methods can help us recover wood from waste streams. However, one crucial aspect of this endeavour is the assessment of the quality of waste wood derived from building demolition, where large volumes of wood could be potentially recovered, and evaluating its suitability for reuse. This thesis aims to address the shortage of wood, by investigating the characteristics, conditions, and potential contaminants present in waste wood recovered from building demolition sites. Through a comprehensive assessment methodology, including physical and visual analyses, the quality of the waste wood will be evaluated. The study will focus on the reusability of recovered waste wood for construction, based on the available quality of wood recovered from the demolition sites. Furthermore, the economic feasibility of reusing waste wood will be examined to determine the suitability of reuse strategies from the recovered wood. The findings of this research will contribute to the development of best practices for material recovery from waste wood and its suitability for reuse. Ultimately, studies such as this thesis aim to promote the efficient utilization of waste wood resources, reduce waste genera-tion, and foster a more sustainable approach to building demolition waste man-agement.
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    Circular building materials management model: Developing platform ecosystem in the Helsinki metropolitan area
    (2024-01-23) Chen, Cheng; Lahtinen, Ella; Kemian tekniikan korkeakoulu; Fink, Gerhard
    The construction industry is a significant contributor to environmental degradation and resource depletion, with its high consumption of finite virgin materials and substantial waste generation. The concepts of a Material and Component Bank (M&CB) and platform ecosystem are seen as effective strategies for managing material recycling and component reuse, thereby promoting sustainability in the industry. Finland, a pioneer in the Circular Economy (CE), aspires to be a global leader in this field by 2035. Despite widespread awareness and participation in the CE, the adoption of CE in buildings remains slow, even with a regional M&CB established since 2018. The primary challenge identified in circulating materials and components is the mismatch between supply and demand for non-virgin products. This thesis explores how a predeveloped platform ecosystem can further facilitate the management of CE building materials in the industry. Using the Helsinki Metropolitan Area as an example, it proposes a model to align supply with demand in an M&CB platform ecosystem by optimizing the structure and processes of the M&CB. Through a literature review analysing system barriers to CE implementation in building projects, interviews on the regional platform Materiaalitori, a focus group analysing actor collaboration, and a case study of a Swedish platform, the thesis identifies key pillars for an M&CB platform ecosystem and develops a model. The proposed model includes an extensive value proposition, a process for synchronizing information between supply and demand projects, and a database map that clarifies the flow between key actors. However, due to limited data collection, the model has not been validated with further research. Future research could involve gathering opinions from a broader participant group, conducting workshops, or using real projects to validate and develop the model. There is also a need to delve deeper into each process in the model and find effective mechanisms accordingly, as the current model provides only a general framework.
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    Assessing the impact of new waste recycling targets on the operation of waste-to-energy incineration plants
    (2024-01-22) Viitala, Matias; Salamäki, Jouni; Kemian tekniikan korkeakoulu; Harjunkoski, Iiro
    As the thesis title suggests, research was conducted on the effect of new waste management legislation on the operation of waste-to-energy (WtE) plants, especially focusing on the new recycling targets introduced in the Waste Framework Directive (WFD). The EU-27 was chosen as the regional scope of the thesis, due to having the world’s most ambitious waste management legislation, which is coherent for all member states, and thus serves as a pacemaker for other countries as well. Furthermore, the EU has extensive waste management data requirements, in order to effectively track the progression in meeting the legal waste management targets. This waste management data is compiled in Euro-stat, which was used in this thesis to gage the current waste management practices in the EU, based on which projection calculations were performed on the waste generation, composition and treatment in the EU-27 until 2040.
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    Hydrophobization of cotton fabrics: Evaluating the efficacy of bio-based material treatments and durable water repellent finishings
    (2024-01-23) Fontell, Tatu; Ilén, Elina; Kemian tekniikan korkeakoulu; Kontturi, Eero
    Cellulosic textiles inherently lack hydrophobic properties, often supplanted by synthetic, less recyclable multi-material solutions in barrier textiles. This thesis explores sustainable alternatives, specifically focusing on surface-modified hydrophobic cotton textiles. The study aims to prove the concept of hydrophobizing cotton textiles utilizing a novel bio-based material treatments to enhance hydrophobicity of commercial Durable Water Repellent (DWR) finishes. The efficacy of these treatments are assessed as is, post-abrasion and post-washing, thereby advancing towards a viable, sustainable solution in barrier textiles. The research evaluated four different DWR finishes on two cotton types (knitted and woven) across six structures. The finishes were applied using a conventional pad-dry-cure process. Select structures underwent additional treatment with a bio-based material treatment, prepared via same methods. The hydrophobic performance was primarily measured through sessile contact angle measurement of a water droplet, guided by a Design of Experiment (DOE) framework. Results indicated that the bio-based material treatment, enhanced hydrophobicity surpassing traditional DWR finishes in pre- and post-abrasion due to increased surface roughness. However, all samples showed reduced hydrophobicity after washing, with DWR-1 and DWR-2 losing effectiveness entirely, whereas DWR-3 and DWR-4 maintained hydrophobic properties post-washing. In conclusion, this study demonstrates the potential of bio-based material treatments in cellulosic textile finishing and creating functional, sustainable barrier textiles out of renewable resources. These findings hold significant implications for developing environmentally-friendly textiles in outerwear and reducing PFCs and synthetic materials in the industry.
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    Gamma-butyrolaktoniluonnonaineiden synteesi kiraalisen altaan molekyyleistä
    (2024-01-23) Majaniemi, Jouni; Holmstedt, Suvi; Kemian tekniikan korkeakoulu; Siitonen, Juha
    γ-Butyrolaktoni -rakenne esiintyy lukuisissa luonnonaineissa niin monosyklisenä yhdisteenä kuin osana kompleksisempia polysyklisiä rakenteita. Monien näistä luonnonaineista on todettu olevan biologiselta aktiivisuudeltaan farmakologisesti kiinnostavia. Tämä tekee näistä yhdisteistä potentiaalisia luonnonainesynteesin kohdemolekyylejä. Tämän diplomityön kirjallinen osuus on rajattu kattamaan γ-butyrolaktoni-rakenteen muodostuminen osana kiraalisen altaan strategiaa hyödyntäviä luonnonainesynteesejä. Vaikka butyrolaktonin muodostamiselle tunnetaan useita menetelmiä, näistä yleisimmin hyödynnetty on syklisaatio intramolekulaarisella esteröinnillä. Kirjallisen osuuden rajaus tukee työn kokeellista osaa, jossa syntetisoitiin luonnollisesta kiinihaposta monosyklinen γ-butyrolaktoni, spikulisporihappo. Kiinihapolle tunnetaan kaksi aiempaa kokonaissynteesiä, joista vanhempi hyödyntää kiraalisen altaan lähtöainetta tosin heikolla selektiivisyydellä. Tässä työssä spikulisporihappoa vastaava butyrolaktoni-rakenne muodostettiin enantiopuhtaana. Laktonin syklisaatiossa hyödynnettiin kiinihapon tertiääristä hydroksiryhmää. Vaikka spikulisporihapon lopullinen rakenne jäi aikataulullisista syistä saavuttamatta, luonnonaineen toisen stereogeenisen keskuksen muodostuminen on tarkasteltu teoreettisella tasolla.
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    Development of Ioncell fibres reinforced bio-based epoxy composite via vacuum infusion technique
    (2024-01-23) Islam, Shariful; Fazeli, Mahyar; Kemian tekniikan korkeakoulu; Lipponen, Juha
    The interest in composites reinforced with cellulose-based fibres is surging due to their eco-friendliness and cost-efficiency. However, their application in high-strength areas is limited, a domain where synthetic/inorganic fibres currently leading. The main concern with synthetic/inorganic fibre composites is their non-biodegradable nature and environmental unfriendliness. Composites made from regenerated cellulose fibres could potentially replace of synthetic/inorganic fibre composites, given their superior strength compared to other cellulosic fibres. “Ioncell fibre” was used in this study, a unique cellulose fibre developed by Aalto University and the University of Helsinki, to produce a composite for comparison with carbon, cellulosic, and glass fibre composites. The main objective is to assess the potential of the biodegradable composite produced from plain weave fabric of Ioncell fibres and a bio-based epoxy matrix via vacuum infusion technique. This thesis delves into the properties of fibres, including their mechanical attributes, degree of polymerization, and morphological structure. It also examines the mechanical and thermal characteristics, water absorption capacity, and hydrophilic/hydrophobic properties of the resulting composite. The study further explores its potential as a substitute for petroleum-based fibre composites, specifically carbon fibre composites. The findings reveal that while the strength of Ioncell fibre is four times less than that of carbon fibre, the strength of the Ioncell composite is nearly half that of the carbon fibre composite. These results could potentially lead to a wider acceptance of biobased Ioncell composites as alternatives to carbon and other synthetic as well as cellulosic fibre composites, contributing to a more sustainable future.
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    Chemical recycling of polycotton textiles: Fractionation of cotton by TEMPO-mediated oxidation
    (2024-01-23) Vuorinen, Julia; Periyasamy, Aravin; Kemian tekniikan korkeakoulu; Hummel, Michael
    Developing chemical recycling methods for textiles is needed to improve the sustainability of the textile industry and provide solutions for recycling textile blends. TEMPO oxidation is a little-studied method in the context of textile recycling, although it could enable the upcycling of cotton in the form of nanocellulose. Earlier literature shows that pure cotton textiles can be successfully recycled by the method. This study aimed to fill the gap in the literature by testing if TEMPO oxidation could also be used for separating the materials of polycotton textiles. This study examined the effects of temperature, pH, and reaction time on the recovery of cotton and polyester as separate fractions. The TEMPO-oxidized polycotton samples were disintegrated using a high-shear mixer. The results showed a significantly lower yield of nanocellulose-like cotton fraction compared to earlier literature. However, the oxidization at a high temperature and pH allowed a high recovery of polyester. The polyester was recovered in fibre form and its purity increased with the temperature, pH, and reaction time. The chemical structure and molecular weight of the recovered polyester were not significantly damaged by the oxidation. The findings suggest that TEMPO oxidation is an interesting method for recycling polycotton textiles. Further studies are needed to improve the efficiency of material separation and the recovery of cotton.
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    Tulenkestävän tiilen ja kaasun välinen vuorovaikutus liekkisulatuksessa
    (2024-01-23) Kansanaho, Marius; Pankka, Iida; Kemian tekniikan korkeakoulu; Lindberg, Daniel
    Tämä opinnäytetyö keskittyy MgO-MgCr2O4 ja Al2O3-Cr2O3 tulenkestävien tiilien suorituskyvyn mallintamiseen liekkisulatusuunissa rikkipitoisten kaasujen altistuksessa. Tämän opinnäytetyön tarkoituksena on mallintaa termodynaamisesti tiilimateriaalien tasapainoa muuttuvissa olosuhteissa korkeissa lämpötiloissa sekä arvioida huokoisuuden ja raekoon vaikutusta materiaalien lämpöominaisuuksiin. Termodynaamiset mallit on tehty FactSage versio 8.2:lla käyttäen FactPS ja FTOxid tietokantoja sekä lisätty magnesium- ja kalsiumsulfaattien uudemmatta termodynaamiset tiedot. Mallinnuksessa keskityttiin tiilimateriaalin koostumus muutoksiin alkuperäisestä koostumuksesta sekä tiilimateriaalien lämpöominaisuuksien muutoksiin. Laskelmat tehtiin 0–1500 ˚C lämpötilassa ja 1 atm paineessa. Tiilien kestävyyttä arvioitiin muuttamalla hapen osapainetta ja lisäämällä kaasufaasin, joka koostuu pääasiallisesti rikkiyhdisteistä. Lisäksi lämmönjohtavuuden ja termisen diffuusiokertoimen muutoksia mallinnettiin muokkaamalla tiilien huokoisuutta ja raekokoa. Termodynaaminen malli näytti, että magnesia-kromia pohjainen tiilimateriaali koostui suurelta osalta magnesium oksidista ja kiinteästä spinelli liuoksesta, joka sisälsi magnesium ja kromi oksidia. Alumina-kromia pohjaisen tiilen koostumus sisälsi yhtä kiinteää korundi liuosta. Hapen osapaine näytti vaikuttavan molempien tiilen koostumukseen. Huomattiin myös, että molemmat materiaalit reagoivat kaasufaasin kanssa muodostaen sulfaatteja. Alumina-kromia kestää korkeissa lämpötiloissa paremmin kuin magnesia-kromia tiili, jossa oksidit hajoavat sulfaateiksi.