Indianapolis / In this thesis, cellulose nanofiber (CNF) reinforced polylactic acid (PLA) filaments were produced for 3D printing applications using melt extrusion. The use of CNF reinforcement has the potential to improve the mechanical properties of PLA, making it a more suitable material for various 3D printing applications. To produce the nanocomposites, a master batch with a high concentration of CNFs was premixed with PLA, and then diluted to final concentrations of 1, 3, and 5 wt% during the extrusion process. The dilution was carried out to assess the effects of varying CNF concentrations on the morphology and mechanical properties of the composites. The results showed that the addition of 3 wt.% CNF significantly enhanced the mechanical properties of the PLA composites. Specifically, the tensile strength increased by 77.7%, the compressive strength increased by 62.7%, and the flexural strength increased by 60.2%. These findings demonstrate that the melt extrusion of CNF reinforced PLA filaments is a viable approach for producing nanocomposites with improved mechanical properties for 3D printing applications. In conclusion, the study highlights the potential of CNF reinforcement in improving the mechanical properties of PLA for 3D printing applications. The results can provide valuable information for researchers and industries in the field of 3D printing and materials science, as well as support the development of more advanced and sustainable 3D printing materials.

My thesis project investigates the potential behind the integration of agricultural practices and living spaces. Combining advanced urban farming methods embedded in a residential context allows for the symbiosis of a typically urban lifestyle with highly efficient food production. The use ol building materials fully derived from renewable sources aims to apply concepts of circular economy in order to find an effective solution to the currently unsustainable building industry, still oriented towards traditional materials.

Ce travail examine la potentielle mise à l'échelle industrielle des procédés de préparation des nanocristaux d'amidon (SNCs). Une caractérisation approfondie (morphologie, viscosité, stabilité thermique et propriétés en nanocomposites) de 5 SNCs différents montre une faible influence de la source botanique, contrairement aux nanocristaux de cellulose. L'analyse du procédé de préparation actuel des SNCs a conduit à 3 nouvelles stratégies d'optimisation et à la définition d'une nouvelle génération de SNCs. Une nouvelle application des SNCs, en emballage multicouche, montre également que les SNCs peuvent être utilisés en couchage et contribuer à diminuer la perméabilité à la vapeur d'eau de certains biopolymères. Une analyse du cycle de vie des SNCs dans ce type d'application est également proposée. Cette étude contribue donc à l'avancée de cette thématique et propose des perspectives prometteuses. / The present work investigates the potential of starch nanocrystals (SNCs) for industrial scaled-up preparation and use. An extensive characterization (morphology, viscosity, thermal stability and properties in nanocomposite) of 5 different SNCs shows, contrary to nanocrystalline cellulose, the limited influence of the botanic source. The analysis of the current preparation process led to three optimization strategies, and to the definition of a new generation of SNCs with smaller dimensions and more homogeneous. A new application of SNCs is presented (multilayer packaging); and showed that SNCs can effectively reduce water vapor permeability of some biopolymers coatings. The life cycle assessment (LCA) of SNCs in this application is also proposed. This study contributes greatly to the advance of the field and offers perspectives for the industrialization of SNCs.

SAMPAIO, K. N. H. Avaliação técnica da utilização de cinzas de combustão do carvão mineral provenientes de termelétrica em argamassas de revestimento. 2017. 89 f. Dissertação (Mestrado em Engenharia Civil)-Centro de Tecnologia, Programa de Pós-Graduação em Engenharia Civil: Estruturas e Construção Civil, Universidade Federal do Ceará, Fortaleza, 2017. / Submitted by Hohana Sanders (hohanasanders@hotmail.com) on 2017-10-24T14:13:48Z No. of bitstreams: 1 2017_dis_knhsampaio.pdf: 2174900 bytes, checksum: 3f9554b5853871212621dd3af72085ff (MD5) / Approved for entry into archive by Marlene Sousa (mmarlene@ufc.br) on 2017-11-07T18:47:19Z (GMT) No. of bitstreams: 1 2017_dis_knhsampaio.pdf: 2174900 bytes, checksum: 3f9554b5853871212621dd3af72085ff (MD5) / Made available in DSpace on 2017-11-07T18:47:19Z (GMT). No. of bitstreams: 1 2017_dis_knhsampaio.pdf: 2174900 bytes, checksum: 3f9554b5853871212621dd3af72085ff (MD5) Previous issue date: 2017-06-14 / In Brazil, 65% of the power generation projects are thermal plants. In the state of Ceará they are responsible for 61.11% of the energy production, highlighting the thermal plants of Pecém I and Pecém II which together have an installed capacity of 1085MW. However, the thermal plants have a major environmental liability for its waste generation, among which stands out the ashes from the combustion of coal (ACC). In order to give a more suitable destination to this waste, its incorporation into raw materials may generate sustainable materials. This thesis proposes to apply those thermal plants’ ashes in mixed mortar of cement and lime, replacing lime by ACC in contents of 0%, 25%, 50%, 75% and 100%, analyzing the characteristics in fresh state and hardened states, as well as its durability. Regarding the fresh state’s tests, the consistency index was fixed and it was quantified the amount of water necessary for each mixture to reach it. Afterwards, the loss of consistency of each mortar was evaluated after five and ten minutes. Finally, the rheology was investigated by the Squeeze-flow method. Regarding the hardened state’s tests, the tensile strength in flexion, the compressive strength and the tensile strength were evaluated. In the end, the durability was analyzed through the permeability test by the pipe method and the cracking aperture lengths. The results were analyzed by an analysis of variance (ANOVA) and the multiple comparisons of means by the Duncan’s test, using the software Statistica 7.0. They indicate that its replacement is technically feasible, as giving a better performance in its workability, resistance and durability. All of the mortars with ACC have shown an improvement in its characteristics compared to the reference mortar, and the mortars with more than 75% of ACC stood out among in resistance, in consistency, and in durability. Keywords: Coal Ash. Sustainable Materials. / No Brasil, 65% dos empreendimentos de geração de energia são usinas termelétricas. No Ceará as mesmas são responsáveis por 61,11% da produção de energia do estado, destacando-se as usinas termelétricas de Pecém I e Pecém II, que juntas possuem a capacidade instalada de 1085MW. Contudo, as usinas termelétricas possuem um grande passivo ambiental pela sua geração de resíduos, dentre os quais se destacam as cinzas da combustão do carvão mineral (CCCM). Para dar uma destinação adequada a esse resíduo, busca-se incorporá-lo em matérias-primas. O presente trabalho propõe aplicar essas cinzas na confecção de argamassas mistas de cimento e cal, substituindo a cal por CCCM nos teores de 0%, 25%, 50%, 75% e 100%, analisando assim suas características tanto no estado fresco quanto no estado endurecido. Com relação aos ensaios no estado fresco, foi fixado o índice de consistência e a partir do mesmo foi quantificada a quantidade de água necessária para cada mistura atingi-lo, em seguida foi avaliada a perda de consistência da argamassa após cinco e dez minutos. Por fim, foi investigada a reologia pelo método do Squeeze-flow. Com relação aos ensaios no estado endurecido, foram avaliadas as resistências à tração na flexão e à compressão e a resistência de aderência à tração. Finalmente, a durabilidade foi analisada através dos ensaios de permeabilidade pelo método do cachimbo e a taxa de abertura de fissuras. Os resultados foram analisados por uma análise de variância (ANOVA) e o comparativo múltiplo de médias pelo teste de Duncan, utilizando o software Statistica 7.0. Os mesmos indicaram que a substituição é viável tecnicamente conferindo um melhor desempenho na sua trabalhabilidade, resistência mecânica e durabilidade. Todas as argamassas com CCCM mostraram melhoras em suas características quando comparadas ao traço de referência, sendo a argamassa com teores acima de 75% de CCCM as que mais se destacaram em resistência, consistência e durabilidade.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-03-07T14:39:58Z No. of bitstreams: 1 marcelaciminicanceladasilva.pdf: 970211 bytes, checksum: 7a88e1c4cbefeffca8caee3fd2f0d9bb (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-04-24T02:01:09Z (GMT) No. of bitstreams: 1 marcelaciminicanceladasilva.pdf: 970211 bytes, checksum: 7a88e1c4cbefeffca8caee3fd2f0d9bb (MD5) / Made available in DSpace on 2016-04-24T02:01:09Z (GMT). No. of bitstreams: 1 marcelaciminicanceladasilva.pdf: 970211 bytes, checksum: 7a88e1c4cbefeffca8caee3fd2f0d9bb (MD5) Previous issue date: 2013-06-26 / O setor da construção civil é responsável por grande parte dos impactos produzidos no meio ambiente. Por isso possui a responsabilidade de desenvolver e introduzir o uso de tecnologias e materiais que proporcionam menor interferência no equilíbrio existente entre o homem e seu ambiente natural. Para seleção de materiais e componentes da construção existem diversas ferramentas, com a finalidade de gerar projetos de edificações mais sustentáveis, ou seja, cuja utilização visa à redução dos impactos ambientais, sociais, econômicos e culturais. Dentre estas ferramentas se encontram os sistemas de certificação ambiental. A presente pesquisa apresenta uma análise comparativa entre alguns destes principais sistemas internacionais e nacionais disponíveis hoje: LEED, HQE, BREEAM, LEED/Brasil, AQUA e CBCS. Esta análise verifica os aspectos positivos e negativos na estrutura e avaliação dos sistemas, assim como os critérios utilizados para a seleção de materiais. Tal análise impulsionou o desenvolvimento de recomendações mais compactas, simples e objetivas, em relação aos critérios analisados. Finalmente, estas recomendações foram empregadas em um questionário estabelecido para pré-avaliação da seleção de materiais em projetos que visam certificação ambiental. Este instrumento apresenta a particularidade de adequação ao panorama nacional, bem como ao conceito global de sustentabilidade, com o emprego de recomendações que vão de encontro às perspectivas atuais, no que se refere à certificação dos empreendimentos da indústria da construção civil. / The construction industry is responsible for a large part of the enviromental impacts and for this reason has the responsibility to develop and introduce the use of new technologies and materials that provide less interference in the balance between man and natural environment. There are several tools that contribute to the selection of material, in order to generate more sustainable construction projects. Using these tools provide the reduction of environmental, social, economic and cultural impacts. This research presents a comparative analysis of some of these major national and international systems available today: LEED, HQE, BREEAM, LEED / Brazil, AQUA and CBCS. This analysis finds positive and negative aspects in the structure as well as the criteria used for the selection of materials. Such analysis allowed the development of more compact, simple and objective recommendations regarding the criteria examined. Finally, these recommendations resulted in a questionnaire established for the assessment of pre-selection of materials for projects seeking environmental certification. This instrument presents an adaptation to the national scene as well as the overall concept of sustainability, using principles that go in favor of the current prospects for the certification of buildings.

Vehicle transportation makes up for a large proportion of global greenhouse gas emissions and is a major contributor of the climate crisis. Even though bikes emit practically no greenhouse gases, the production phase still cause environmental damages. Especially the choice of materials dictates the sustainability of a bike. Thus, the aim of this project is to problematize the current material choices made in the bike industry and explore how sustainable materials can be applied in a product-oriented industry to find sustainable design solutions. The material used in the project is provided by PaperShell Industries that supply a cellulose based and circular material for B2B. In order to fulfil the aim of the project a bike saddle was designed. The theory of circular design was guiding the design process, and various methods was applied. Focus groups were combined with co-designing in an innovation process. The design process was divided into three parts: research, ideation, and realisation. In the first part, focus groups, benchmarking, research ergonomics and research through design were conducted. The second part included brainstorming, mind mapping/tree diagram and moodboard. In the final step sketches and CAD-models were made and an innovation process was applied. Following this design process, the author concluded that fully cellulose based materials are suitable for the bike industry because of the low climate impact. The material also has the right properties for a bike product. The project suggests that circular design can be realized by implementing sustainable materials such as cellulose based materials,

One of the largest problems that stands before us is the quest to find sustainable alternatives to fossil-based materials. Fossil-based products can be found all around us in our society. This quest has forced us to look for new ways to build materials. Synthetic polymer materials have traditionally been produced from fossil-based starting materials however, in modern times studies regarding biobased superseders for the unsustainable starting materials has been conducted.  One of these new potential building blocks is ferulic acid (FA) that is an aromatic cinnamic acid. FA has previously been used as an antioxidant but since it in addition is aromatic, have more than two functional groups and contains a double bond between two carbons it holds a large potential for polymeric synthesis.  FA has been isolated from agricultural side streams such as sugar beet pulp, flax shives, wheat- and corn bran through enzymatic release and pressurised low-polarity water extraction (PLPW).  One of the largest areas of use regarding FA is the biological applications. It has been proven to be effective protection against UV-radiation which open up possible uses in the textile industry, cosmetics and skincare. FA has also shown biomedical properties such as antiallergic, anti-inflammatory, anti-diabetic, anticarcinogenic and antiviral properties among others.  Two of the most common polymerization methods are free radical- and step-wise polymerization. FA shows great promise for the possibility to polymerize through both these methods since it has a double bond and more than two functional groups. Polymer materials produced from FA has been done with step-wise polymerization. The polymers showed thermostable and possibly biodegradable properties. Free-radical polymerization requires a monomer with a sterically unhindered double bond and for that reason the FA must be modified in order to polymerize using free radicals. This modified monomer has been produced in a small laboratory scale and can in theory be polymerized through radical polymerization. / Ett av de största problemen som vi står inför i modern tid är hur vi ska ersätta material som är producerade från fossila bränslen. Dessa material finns överallt i vårt moderna samhälle och spelar en betydelserik roll i vår infrastruktur. Detta har tvingat oss att undersöka andra miljövänligare källor för att se om dessa kan ersätta de fossila. Polymera material är ett exempel på material som tidigare har haft en fossil bas. På grund av detta har dessa material och hur dem kan producerats undersökt för att se om det finns en alternativ biobaserad källa.  Ferulsyra är en aromatisk kanelsyra som är mest känd för att ha antioxidatiova egenskaper. Utöver detta innehåller ferulsyra en dubbelbindning mellan två kol och dessutom fler än två funktionella grupper vilket indikerar att den kan vara en möjlig monomer för polymersyntes.  Ferulsyra kan produceras från sidoströmmar från jordbruksindustrin så som till exemper sockerbetsmassa, linhår och vete, både genom enzymatiska reaktioner eller med hjälp av extraktion med ett lösningsmedel.  En av de största användningsområdena gällande ferulsyra är inom biologiska applikationer. Den kan bland annat användas som solskydd, både inom hudvårdsindustrin och som ytbeläggning i textilier. Ferulsyra har också uppvisat medicinska egenskaper som visar på att det kan användas mot allergier, inflammationer, diabetes, canser och virussjukdomar.  De två vanligaste metoderna för polymersyntes är fri radikalpolymerisation och stegvis polymerisation. Ferulsyra uppvisar stor potential för att kunna användas som monomer i båda metoderna då den innehåller en dubbelbindning mellan två kol och fler än två funktionella grupper. Syntes av ferulsyra genom stegvis polymerisation har genomförts. Resultatet var att de producerade materialen uppvisade termostabila och biologiskt nedbrytbara egenskaper. För att fri radikalpolymerisation ska vara möjligt med ferulsyra som monomer krävs det att dubbelbindningen inte är steriskt hindrad. Detta innebär att ferulsyra först måste modifieras innan polymerisationen är möjlig. Dessa modifieringar har genomförts på labbskala och den producerade monomeren är teoretiskt sätt möjlig att polymerisera genom fri radikalpolymerisation.

<p dir="ltr">Cold mix asphalt (CMA) is an eco-friendly paving material produced at ambient temperatures, offering energy savings by requiring less energy to decrease asphalt binder viscosity. This technology eliminates the need for heating during the mixing and compaction processes, further magnifying its economic benefits when used as a cold-in-place recycling technique. Unlike hot mix asphalts that gain strength through cooling, CMA achieves its final strength through a curing process involving the evaporation of volatiles and the hardening of the emulsified asphalt binder over time. However, its reliance on a curing process for strength development raises concerns about its short-term performance.</p><p dir="ltr">A typical CMA mixture consists of four main components: air voids, mineral aggregate, water, and asphalt droplets suspended in water. The presence of water can significantly influence the overall performance of the mixture under both traffic and environmental loads. Most existing studies on CMA have predominantly focused on the behavior of the mixtures after they have fully cured. However, in real-world scenarios, pavements are often subjected to various stresses during the curing process, which takes up to several months. As a result, premature distress can compromise the early performance of the pavement. Asphalt undergoes significant chemical and physical changes throughout this phase that can influence its final characteristics and in-situ performance. Overlooking this crucial stage can lead to a poor understanding of the material's capabilities and limitations. Despite the importance of this phase, the micromechanical and rheological behaviors of CMA during curing remain largely uncharted territories. Therefore, this dissertation aims to investigate the micromechanical performance of CMA during the curing phase.</p><p dir="ltr">This research study was performed in two study scales: Mastic and Mixture. The first scale focused on the rheological performance of emulsified-cold asphalt mastic (ECAM), considering varying curing levels, different filler-binder ratios, and filler surface treatments. Comprehensive rheological tests, including frequency sweep, temperature sweep, and strain sweep tests, were conducted on fully and partially cured mastic samples, i.e., 20%, 40%, 60%, and 80%, across a wide range of test temperatures. To analyze the physio-chemical adhesion properties between filler and emulsified asphalt, an analytical tool named the “asphalt-filler interaction” theory was formulated to determine the adhesion bond between filler and binder in the presence of moisture. Microscopic images were also captured to analyze the micro-structure and moisture interaction in the CMA’s matrix. Moreover, the presence of moisture in the CMA brings up another complexity during curing time: The water-to-ice phase transition. Normal Force (Nf) was used as a novel measurement parameter to determine water-ice phase transition effects on the rheological study of emulsified mastic. In the mixture scale, mechanical tests were performed on specimens fabricated with two gradations at fully and uncured CMA samples. The mixture experimental tests included the dynamic modulus test, Illinois flexibility index test, Hamburg wheel loaded test, and disc-shaped compact tension test.</p><p dir="ltr">This dissertation presents a thorough analysis and detailed findings that illuminate the complex relationships and behaviors of CMA, particularly at the mastic scale. A significant observation is the direct influence of the filler-to-binder ratio on the curing time; increasing this ratio prolongs the curing process while using a filler with less surface area accelerates it. Notably, 25% of the filler-to-binder ratio enhances the rheological properties of ECAM, particularly at lower loading frequencies. This study further pinpoints the 60% curing level as a crucial threshold in the CMA curing process. Below this, moisture's effect on rheological performance overshadows that of the primary asphalt material, leading to brittle characteristics in freezing conditions and viscous behavior at intermediate temperatures. In the curing stage, the trapped and blocked waters that emerge during the coalescence phase of the emulsified asphalt breaking contribute to the extended curing time of ECAM.</p><p dir="ltr">Additionally, freezing temperatures yield a water-to-ice phase change in uncured ECAM, resulting in a brittle behavior. Interestingly, a direct correlation emerges between curing percentage and freezing point; higher curing percentages relate to lower freezing points. Another significant discovery is the appearance of micropores in fully-cured ECAM, likely due to water evaporation and emulsifier presence, which potentially compromises its performance compared to ECAM fabricated with residual asphalt binder. Furthermore, adjusting the pH, especially by treating limestone filler with hydrochloric acid (HCl), showed noticeable improvements in CMA’s rheological behavior. At the mixture scale, the CMA mixture contained a higher filler-binder ratio in the mixture scale, presenting a better viscoelastic performance and higher cracking resistance at intermediate and freezing temperatures. Moreover, a minimum amount of water, 2.5% by total mass, added to the CMA mixture is essential to ensure adequate mixability, workability, and compactibility. Viscoelastic analysis showed that the curing process changes the transition point from elastic to viscous behavior of CMA mixtures. This shift towards lower frequencies results in a CMA mixture with poor resistance to higher temperature performance.</p>

This thesis work aims to develop electrochemical sensors for sub-ppb level detection of inorganic and organic pollutants in drinking water with environmentally benign materials and processes. While traditional laboratory-based methods such as mass spectroscopy, and chromatography have been used to analyze the concentration of contaminants in drinking water, miniaturized electrochemical sensors offer a compelling alternative to those methods, enabling rapid on-site cost-effective detection of low concentrations of pollutants. In this research, a set of three-electrode sensors was designed and fabricated on a flexible substrate using a screen-printing technique. Additionally, an in-situ electrochlorination process was implemented to create the reference electrode. These sensors were utilized to precisely detect lead ions and perfluorooctane sulfonate (PFOS) in drinking water. The first set of sensors was fabricated to measure the concentration of lead ions, a toxic inorganic pollutant, in potable water. The novelty of the proposed research lies in using non-toxic, biodegradable sodium alginate grafted with 2- acrylamido-2-methyl propane sulfonic acid (AMPS) and conductive fillers for trace-level lead ion detection in water. The principle of square wave anodic square wave stripping voltammetry (SWASV) was used to determine the trace level lead ion concentration. Employing a similar approach with a different material, a PFOS sensor was developed. Utilizing chitosan, one of the sustainable and biodegradable biopolymers found in crustacean shells, rapid parts-per-trillion (ppt) level PFOS detection by electrochemical impedance spectroscopy (EIS) was demonstrated. The proposed sensors made low-cost electrochemical detection of contaminants such as lead ions and PFOS possible with eco-friendly materials and processes.

The purpose of this Master’s thesis is to broaden the horizon of customizable features available in the luminaire design industry. The aim was to study if enhanced customization features like light distribution, colour of light and use of sustainable materials can help foster emotional attachment and increased usage with the possibility of extending luminaire life. The conclusion here is drawn based on literature review, survey, prototype development and user experiment followed by assessment questionnaire. The table lamp prototype created allowed participants to change colour of light, materials and light distribution of the luminaire according to their mood and preferences. The study indicates these enhanced customization features positively influenced the participants mood, ambience and usage of the product. The survey and user assessment were both qualitative and quantitative in nature. However, all the data collected was quantified for a better understanding of the impact these enhanced features had on the participants. The participants felt a sense of ownership, satisfaction, and accomplishment because of the customization process. As a result, participants say they would prefer repair and replacement over disposal and would want to keep using the luminaire for a long time. The study concluded that enhanced customization features in luminaries can foster emotional connections, increase longevity, and promote sustainable consumption.