This thesis examines the value of using dispersed conductive fillers as a stress/strain sensing material. The effect of the intrinsic conductivity of the filler on the ability to be effective and the influence of filler concentration on the conductivity are also examined. To meet these objectives, nanocomposites of polyvinylidene fluoride (PVDF) with carbon nanofibers (CNFs) and carbon nanotubes (CNTs) were prepared by melt-blending using a twin screw extruder. Since PVDF has a potential to be piezoresistive based on the type of crystalline phase, the effect of CNFs on PVDF crystallinity, crystalline phase, quasi static and dynamic mechanical property was studied concurrently with piezoresponse. Three time dependencies were examined for PVDF/CNTs nanocomposites: quasi-static, transient and cyclic fatigue. The transient response of the strain with time showed viscoelastic behavior and was modeled by the 4-element Burger model. Under quasi-static loading the resistance showed negative pressure coefficient below yield but changed to a positive pressure coefficient after yield. Under cyclic load, the stress-time and resistance-time were synchronous but the resistance peak value decreased with increasing cycles, which was attributed to charge storage in the nanocomposite. The outcomes of this thesis indicate that a new piezoresponsive system based on filled polymers is a viable technology for structural health monitoring.

No description available.

This master’s thesis was conducted at the Department of Nanotechnology and Functional Materials at Ångström Laboratory as part of an on-going project to develop hybrid nanocomposites from Cladophora cellulose and a sub-type of metal-organic frameworks; zeolitic imidazolate frameworks (ZIFs). By utilizing a state-of-the-art interfacial synthesis approach, in-situ growth of ZIF particles on the cellulose could be achieved. TEMPO-mediated oxidation was diligently used to achieve cellulose nanofibers with carboxylate groups on their surfaces. These were ion-exchanged to promote growth of ZIF particles in a nanocellulose solution and lastly, metal ions and organic linkers which the ZIFs are composed of were added to the surface functionalized and ion-exchanged nanocellulose solution to promote ZIF growth. By vacuum filtration, mechanical pressing and furnace drying; freestanding nanopapers were obtained. A core-shell morphology between the nanocellulose and ZIF crystals was desired and by adjusting the metal ion concentration, a change in morphologies was expected. The nanocomposites were investigated with several relevant analytical tools to confirm presence, attachment and in-situ growth of ZIF crystal particles upon the surface of the fine nanocellulose fibers. Both the CNF@ZIF-67 and CNF@ZIF-8 nanocomposites were successfully prepared as nanopapers with superior surface areas and thermal properties compared to pure TEMPO-oxidized cellulose nanopapers. The CNF@ZIFs showcased hierarchical porosities, stemming from the micro- and mesoporous ZIFs and nanocellulose, respectively. Also, it was demonstrated that CNF@ZIF-8 selectively adsorbed CO2 over N2. Partial formation of core-shell structure could be obtained, although a relationship between increased metal ions and ZIF particle morphology could not wholly be observed.

Nanoparticles are very interesting building blocks. Their large surface-to-bulk ratio gives them different properties from those of larger particles. Controlling their assembly can greatly affect macroscopic material properties. This often happens in nature, resulting in macroscopic materials with properties far better than those of similar human-made materials. However, in this fast-growing research field, we may soon compete with nature in certain areas. This thesis demonstrates that the distribution and orientation of nanocellulose particles can be controlled, which is crucial for many applications. Nanocellulose is an interesting nanoparticle, for example, because of its high strength, low thermal expansion, and high crystallinity. Nanocellulose particles are called nanofibrillated cellulose (NFC) or cellulose nanocrystals (CNCs). NFC is obtained from wood by mechanically shearing apart fibrils from the fiber wall and to obtain CNCs, parts of the cellulose are broken down by hydrolytic acidic reactions, most commonly, prior to homogenization. NFC particles are longer and less crystalline than are CNCs, but both are similar in width. The particles attract each other in aqueous dispersions and have a high aspect ratio and, thus, a large tendency to aggregate. The rate at which this occurs is typically reduced by charging the particles, generating an electrostatic repulsion between them. To fully utilize the many interesting properties of nanocellulose, the aggregation and orientation of the particles have to be controlled; examining this delicate task is the objective of this thesis. The limits for particle stability and aggregation are examined in papers 2–3 (as well as in this thesis) and orientation of the particles is investigated in papers 3–5. In addition, the liberation of the nanoparticles from different types of wood fibers is studied in papers 1 and 2. It was found that the liberation yield improved with increased fiber charge. In addition, the charge of the fibrils is higher than the charge of the original fibers, indicating that the fibrils were liberated from highly charged parts of the fibers and that the low-charge fraction was removed during processing. Aggregation was both theoretically predicted and experimentally studied. A theoretical model was formulated based on Derjaguin–Landau–Verwey–Overbeek theory, which is intended to predict the influence of salt, pH, and particle charge on the colloidal stability of the NFC. To predict the experimental trends, specific interactions between salt counterions and the particles charges had to be included in the model, which greatly increased the effect of salt on the NFC stability. Below the particle overlap concentration, instability induced by pH or salt created small sedimenting flocs, whereas above the overlap concentration the system gelled. Increasing the particle concentration further also gels the system. Orientation of nanocellulose was first achieved by shearing, salt- or acid-induced NFC gels. This oriented the fibrils and increased the gel modulus in the direction of shear. The orientation persisted after the shear strain was released and did not cause breakdown of the macroscopic gel. The orientation is probably due to rotation in the interfibril crosslinks, which is possible because the crosslinks are physical, not covalent.      Second, orientation was also induced by elongational flow. Shear and acceleration forces were combined to align fibrils in the direction of the flow. The orientation was then frozen by gelation (adding salt or reducing the pH). Drying the gel threads created filaments of aligned fibrils with a higher specific strength than that of steel.      Finally, CNC particles could be aligned on flat surfaces. The particles were first forced to align due to geometrical constraints in grooves on a nanowrinkled surface. The CNCs were then transferred to a flat surface using a contact-printing process. This created surfaces with lines of highly aligned CNCs, where the line–line spacing was controlled with nanometer precision. / <p>QC 20131114</p>

Submitted by Nathália Faria da Silva (nathaliafsilva.ufv@gmail.com) on 2017-07-11T14:46:51Z No. of bitstreams: 1 texto completo.pdf: 384347 bytes, checksum: c3a82089898568ec2c1e119d1cf4f74a (MD5) / Made available in DSpace on 2017-07-11T14:46:51Z (GMT). No. of bitstreams: 1 texto completo.pdf: 384347 bytes, checksum: c3a82089898568ec2c1e119d1cf4f74a (MD5) Previous issue date: 2003-02-26 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Três experimentos foram conduzidos para avaliar possíveis interações entre os perfis de carboidratos solúveis em detergente neutro e fontes de fibra para cabras leiteiras sob dietas contendo baixa concentração de fibra. No primeiro trabalho, foram utilizadas cinco cabras em delineamento em quadrado latino 5 x 5 para avaliar o efeito de cinco quocientes entre amido + açúcares solúveis em relação à fibra solúvel em detergente neutro (AmAs:FSDN), em base forrageira de feno de alfafa (Medicago sativa). Os tratamentos foram definidos pela razão entre AmAs:FSDN de 0,89; 1,05; 1,24; 1,73; e 2,92. Foram medidos o consumo, a digestibilidade, o balanço de nitrogênio, a produção e constituintes lácteos, além do comportamento ingestivo. A digestibilidade da matéria seca, da FDN e dos Carboidratos Solúveis em Detergente Neutro (CSDN) reduziu de forma linear, com o aumento nos níveis de amido e açúcares. O aumento na razão AmAs:FSDN reduziu a excreção urinária, resultando em incremento na retenção de nitrogênio. O segundo trabalho foi planejado da mesma forma que o primeiro, com exceção da fonte de fibra forrageira das dietas, que, neste caso, foi a o feno de capim-Tifton 85 (Cynodon spp), o que resultou em alteração das razões entre AmAs:FSDN estudadas, que foram: 1,34; 1,94; 2,08; 3,95; e 9,04. Houve tendência de efeito quadrático da razão estudada sobre o consumo de matéria seca, o que pode ter contribuído para o efeito significativo dos tratamentos sobre o consumo de CSDN, proteína bruta (PB), extrato etéreo (EE) e energia (EL 3X ). A digestibilidade da matéria seca (DMS) reduziu linearmente com o aumento nos níveis de amido e açúcar, que foi influenciada pela redução, também linear, da digestibilidade da fibra e do CSDN. A retenção de nitrogênio foi afetada de maneira quadrática pelo perfil do CSDN, com ponto de máximo de 5,06 para a razão entre AmAs:FSDN. A produção de leite apresentou ajuste semelhante e teve ponto de máximo de 6,07. As concentrações de lactose e gordura láctea não foram influenciadas mas o teor de proteína bruta respondeu de forma linear positiva ao aumento na razão AmAs:FSDN. No terceiro experimento, cinco cabras não lactantes, fistuladas no rúmen e abomaso, foram distribuídas em um delineamento experimental em quadrado latino 5 x 5. A variável independente foi a razão entre as concentrações de amido, associado ao açúcar solúvel, e a fibra solúvel em detergente neutro (AmAs:FSDN) em dietas à base de feno de capim-Tifton 85 (Cynodon spp.). Os tratamentos foram: 0,82; 1,30; 1,63; 2,94; e 5,35 da razão AmAs:FSDN. Não houve efeito dos tratamentos sobre o consumo voluntário de MS, PB, EE, FDN, CSDN e energia. O aumento na razão AmAs:FSDN reduziu linearmente a digestão ruminal da MS, da FDN, da PB e dos CSDN, mas, de maneira contrária, a digestão intestinal destes componentes aumentou linearmente, resultando em nenhuma alteração na digestibilidade total. O aumento na proporção de amido na dieta reduziu de forma linear o pH e elevou o tempo em que esta variável permaneceu com valores abaixo do valor de 6,2. O perfil de ácidos graxos, a amônia ruminal e taxa de passagem não foram afetados pelos tratamentos. A maior participação de FSDN nas dietas reduziu a eficiência de síntese e o fluxo de proteína microbiana e de proteína total para o abomaso. Em dietas com alta concentração de CSDN à base de alfafa, a manutenção dos teores de amido e açúcar solúvel em relação à FSDN, entre 0,89 e xxiii2,92, não influi no consumo de matéria seca, energia ou proteína e, dessa maneira, não altera a produção de leite em cabras leiteiras. De maneira inversa, o uso da forrageira Tifton 85 (Cynodon spp.) determina maior razão entre AmAs:FSDN, o que poderia maximizar a produção de leite ao atingir o valor de 6,07. O aumento na concentração de FSDN, em substituição ao amido e açúcares, resulta em menor eficiência de síntese e fluxo de proteína microbiana para o abomaso, aumentando a excreção de nitrogênio e reduzindo o percentual de proteína bruta do leite. Em dietas com alta proporção de CSDN, o perfil dos carboidratos deve ser observado, especialmente quando a base forrageira for de gramíneas, associando os efeitos positivos da FSDN sobre a manutenção do pH ruminal e do amido sobre a eficiência e o fluxo de proteína microbiana para o abomaso. / Three experiments were conducted to evaluate possible interactions between neutral detergent soluble carbohydrate profile and fiber sources in low fiber diets for dairy goats. In the first work, five goats were assigned to a 5 x 5 Latin square design to evaluate the effect of five ratio of starch + soluble sugars to neutral detergent soluble fiber (StSu:NDSF) in alfalfa hay-based diets. Treatments were defined by the ratio of StSu:NDSF at 0.89, 1.05, 1.24, 1.73 and 2.92. Intake, digestibility, nitrogen balance, milk yield and composition, and eating behavior were measured. Digestibility of dry matter, of NDF, and of NDSC linearly reduced as both starch and sugar levels increased. Higher values of the ratio StSu:NDSF resulted in a reduction of urinary excretion with a raise in nitrogen retention. The second experiment was designed similarly to the first one, but the forage source (Tifton 85 hay, Cynodon spp) resulting in different ratios of StSu:NDSF, that is 1.34, 1.94, 2.08, 3.95, and 9.04. There was a tendency for a quadratic effect on dry matter intake, which may have contributed for the significant effect of treatments on intake of NDSC, crude protein, ether extract, and xxvenergy (NE 3x ). Dry matter digestibility linearly reduced by increasing Starch and Sugar levels as a consequence of linear reductions in both fiber and NDSC digestibility values. Nitrogen retention was quadractly affected by the NDSC profile, with a maximum at the ratio of 5.06. Milk yield, presented a similar adjustment, with maximum at 6.07. Milk lactose and fat percentage were not influenced, whereas crude protein content showed positive linear response to the increase of StSu:NDSF ratio. In the third experiment, five non-lactating goats, fistulated in both rumen and abomasum were assigned to a 5 x 5 Latin square design. The ratio between starch, associated with soluble sugar, to neutral detergent soluble fiber (StSu:NDSF), in Tifton 85 (Cynodon spp.) hay based diet, was the independent variable. Treatments were set as 0.82, 1.30, 1.63, 2.94, and 5.35 of the StSu:NDSF ratio. No treatment effect was observed on intake of DM, CP, EE, NDF, NDSC and energy. Ruminal digestion of DM, NDF, CP and NDSC reduced linearly by increasing the StSu:NDSF ratio, whereas a linear increase in intestinal digestion was observed, resulting no change in total digestibility. Adding starch and sugar to diets reduced linearly rumen pH values, and increased time in which pH was maintained under the value of 6.2. Fatty acids profile, ruminal ammonia, and passage rate were not affected by treatments. Higher contribution of dietary NDSF resulted in reduction of microbial efficiency and of total protein flow to abomasum. In alfalfa-based diets with high NDSC concentration, the maintenance of starch and soluble sugars contents, in relation to NDSF, from 0.89 to 2.92, did not affect intake of both nutrients and milk yield in dairy goats. Conversely, the use of Tifton 85 hay (Cynodon spp.) determine a higher ratio of StSu:NDSF which could maximize milk yield as ratio reaches 6.07. Replacement of starch and soluble sugars by NDSF results in lower microbial efficiency and flux of protein to abomasum, which in turn increase excretion of nitrogen and reduces milk protein percentage. In diets with high proportion of NDSC the carbohydrate profile should be observed, especially on those based on grasses, by associating the positive NDSF effects on maintenance of ruminal pH and of starch on improving efficiency and microbial protein flow to the abomasum.

No description available.

Background matching, a form of camouflage, involves species developing patterns and coloration that closely resemble their environment. Humans have utilized camouflage and background matching, particularly in military applications, to reduce detectable characteristics, known as signatures. Recent advancements in sensor systems necessitate the development of effective camouflage in the short-wave infrared (SWIR) range (0.9 – 2.5 µm). However, absorption of SWIR radiation is heavily influenced by water, and dry textile materials may be easily detectable against a forest background due to their low water content. To address this challenge, this master's thesis explores the integration of hydration onto a textile fabric to reduce the signature in SWIR. Various fabric types were included in this study. The optical properties of these textiles, both when wet and dry, were evaluated using SWIR imaging and UV-VIS-NIR spectroscopy, and compared to foliage. Surface modifications were employed to introduce hydrophobic properties to the fabric, such as the application of water-repelling agents (Nikwax and OrganoTex) or functionalized silica nanoparticles. The water evaporation rates of untreated and surface-treated fabrics were assessed. However, the hydrophobic surface did not significantly reduce water evaporation from the fabrics. Similarly, the addition of a nanocellulose-based hydrogel on the fabric surface did not result in a significant change in evaporation. Combining the hydrogel with water-repelling solutions in a multilayer configuration indicated prolonged evaporation, but further tests are required to validate this finding. This master's thesis demonstrates that introducing water into a dry textile fabric alters its spectral properties, making it more similar to foliage. However, the primary challenge lies in retaining water within the material for improved camouflage in SWIR wavelengths.

[pt] Atualmente as fontes hídricas estão em constante poluição por despejos de produtos químicos (incluindo metais pesados), biológicos e entre outros. Visto que a celulose pode ser encontrada em árvores e é caracterizada como um homopolímero de alto peso molecular que possui hidroxilas, que se projetam lateralmente, formando estruturas bastante ordenadas que nas regiões menos ordenadas, permite que esses grupos hidroxilas realizem ligações de hidrogênio com outras moléculas polares, podendo absorver grande quantidade de água. Quando se reduz o tamanho das fibras para uma escala nanométrica, caracterizando como nanocelulose que possui uma área superficial maior quando comparada a celulose em seu tamanho de origem. A nanocelulose (CNF) foi obtida por rota química, com os reagentes NaBr, NaClO em pH 10, NaOH, celulose e catalisador TEMPO. A reação ocorre à medida que o pH tende a diminuir, logo, quando o pH se manter constante em 10 a reação finalizou. A CNF obtida possui alta cristalinidade, largura entre 2 e 8nm, potencial zeta entre -30 e -10mV e, um início de degração em 195 graus celsius e energia de ativação de 40,9358 e 45,5978kJ/mol. Dada tais características, água contaminada com metais dissolvidos como magnésio, cobalto e mercúrio foram colocadas em contato com a CNF, durante 3h com uma redução de mais de 90 porcento da concentração, além disso, uma pequena curva de adsorção do cobalto foi plotada analisando a adsorção ao longo de 12h. Portanto, conclui-se que a CNF pode ser utilizada para adsorção de tais metais. / [en] Actually water sources are constantly polluted by chemicals (including heavy metals), biologicals and others. Since a cellulose can be found in plants and is characterized as a high molecular weight, homopolymer and has hydroxyls that are out of surface, forming well-ordered structures, that in the less orderly regions, it allows these hydroxyl groups to perform hydrogen bonding with other molecules polars, affording absorb a large amount of water and other polar molecule. When reducing size of the fibers to a nanometer scale, it is called as nanocellulose, has a larger surface area when compared to the cellulose in original size. Nanocellulose (CNF) was obtained by the chemical route with NaBr, NaClO at pH 10, NaOH, cellulose and TEMPO catalyzer. The reaction occurs as the pH decreases, so when the pH keeps constant at 10 the reaction ends. CNF has high crystallinity, width between 2 and 8nm and potential zeta between -30 and -10mV and, mass loss starts at 195 celsius degrees with activation energy 40,9358 e 45,5978kJ/mol. Given these technical features, water contaminated with dissolved metals, such as magnesium, cobalt and mercury, were placed in contact with the CNF for 3h observing more 90 percent reduction of the concentration, besides, a small cobalt adsorption curve was plotted, by analyzing adsorption over 12h. Therefore, conclude that CNF can be used for adsorption of these metals.

Neste trabalho, foram realizados pré-tratamentos para maximizar o fracionamento dos componentes da biomassa e alcançar uma alta valorização do material. Relatamos uma integração de etapas de pré-tratamentos obter três produtos de alto valor agregado em um conceito de biorrefinaria: xilooligosacarídeo (XOS), xilose e celulose nanofibrilhada (CNF). Foi estudada a maximização de valor da fração hemicelulosica do bagaço de cana-de-açúcar através de extração hidrotérmica, de preferência na forma de XOS, e também se avaliou a produção de CNF, um nanomaterial emergente com inúmeras aplicações em diversos setores, como papel, têxteis e eletrônicos. Para selecionar a melhor condição de solubilização de hemicelulose na forma de XOS, as condições do processo hidrotérmicos foram avaliadas com planejamento experimental estatístico 23, com rotação do tipo estrela, a fim de analisar o efeito combinado de temperatura, tempo e concentração de ácido (H2SO4). A melhor condição experimental para produzir XOS com alto rendimento e seletividade foi a 182 °C durante 5,5 minutos e sem adição de ácido, obtendo um hidrolisado com recuperação de 43 % da xilana inicial na forma de XOS e apenas 2 % na forma de xilose. Um segundo tratamento hidrotérmico foi realizado com o objetivo de remover a xilana residual do bagaço tratado, de preferência na forma de XOS. Devido à alta recalcitrância do material, não foi possível encontrar uma condição experimental para obter alta seletividade para XOS no segundo pré-tratamento e, portanto, foi escolhido obter um hidrolisado rico em xilose, um produto que também possui diversas aplicações. As melhores condições experimentais para se obter um hidrolisado rico em xilose foram determinadas a 168 ° C durante 5,5 minutos e 1,01% m/m de H2SO4, obtendo-se uma recuperação de 36 % da xilana presente inicialmente no bagaço na forma de xilose e apenas 3 % na forma de XOS, sendo este um processo altamente seletivo para recuperação da xilana na forma monomérica. A fração sólida oriunda das etapas de extração da xilana foi deslignificada com NaOH e branqueada em duas etapas, com H2O2 em meio alcalino e com NaClO2 em meio ácido, obtendo pasta celulósica com alto teor de celulose (88,9% m/m de celulose). A polpa celulósica foi processada em um refinador de disco mecânico (SupermassColloider) para produzir celulose nanofibrilada (CNF-B). As propriedades morfológicas do CNF-B foram avaliadas e verificou-se que foi semelhante à nanocelulose de polpa Kraft (CNF-K), em relação as suas dimensões, produzida nas mesmas condições. Além disso, a produção do CNF-B consumiu cerca de um terço da energia necessária para obter o CNF-K. O balanço de massa final do processo mostrou uma alta recuperação dos carboidratos originais em produtos de alto valor agregado. A recuperação da xilana foi de cerca de 88% m/m, sendo 43% m/m de XOS e 36% m/m de xilose. O alto conteúdo recuperado dos coprodutos demonstra a alta seletividade das otimizações realizadas. Por fim, o processo obteve alta recuperação e conversão de celulose à CNF-B, com um rendimento de 88% m/m. / A pretreatment has been pursued to maximize the biomass components and achieve a high material´s valorization. Here, we report an integration of pathways, which have been effective to obtain three high value-added products in a biorefinery concept: XOS, xylose and cellulose nanofibrillated (CNF). The maximization of hemicellulose fraction was studied through hydrothermal extraction from sugarcane bagasse, preferably oligosaccharides (XOS) form, and it was also evaluated CNF production, an emerging nanomaterial with numerous applications in diverse sectors such as paper, textiles and electronics. To select the best condition of hemicellulose solubilization in the form of XOS, the hydrothermal process conditions were evaluated with statistical experimental design to analyze the combined effect of temperature, time and acid concentration (H2SO4). The best experimental condition to produce XOS with high yield and selectivity was at 182 ° C for 5.5 minutes and without acid addition, obtaining a hydrolysate with 75% w/w of XOS content, which corresponds to 43% w/w of the original xylan. A second hydrothermal treatment was performed with the aim of remove a residual xylan from treated bagasse, focusing in XOS form. Because of the high susceptibility of the material, it was not possible to find an experimental condition to achieve high selectivity for XOS in the second pretreatment and, therefore, it was chosen to obtain a hydrolyzate rich in xylose, a product with many applications as well. The best experimental conditions to the hydrolyzate system based in xylose was determined at 168 ° C for 5.5 minutes and 1.01% w/w H2SO4, obtaining a xylose\'s yields of 36% w/w (initial xylan). The solid fraction of the second hydrothermal step was deslignificated with NaOH and bleached in two steps, with H2O2 at alkaline medium and with NaClO2 at acid medium, obtaining cellulosic pulp with high cellulose content (88.9% w/w of cellulose). Cellulosic pulp was processed in a mechanical disc refiner (SupermassColloider) to produce fibrillated nanocellulose (CNF-B). The morphological properties of the CNF-B were evaluated, and it was found to be similar to Kraft pulp nanocellulose (CNF-K) produced at same conditions. Besides that, the production of CNF-B consumed about one third of the energy required to obtain CNF-K. CNF-B and CNF-K were also compared in terms of mean diameter and it was obtained 56.72 nm and 36.83 nm, respectively. The final mass balance of the process showed a high recovery of the original carbohydrates in means of high value-added product. The recovery of xylan was around 88%, being 43% w/w of XOS and 36% w/w of xylose. The high content recovered of the co-products demonstrate the high selectivity of the optimizations performed. Thus, this resulted in a high recovery and conversion of cellulose in the CNF-B with a yield of 88% w/w.

Neste trabalho, foram realizados pré-tratamentos para maximizar o fracionamento dos componentes da biomassa e alcançar uma alta valorização do material. Relatamos uma integração de etapas de pré-tratamentos obter três produtos de alto valor agregado em um conceito de biorrefinaria: xilooligosacarídeo (XOS), xilose e celulose nanofibrilhada (CNF). Foi estudada a maximização de valor da fração hemicelulosica do bagaço de cana-de-açúcar através de extração hidrotérmica, de preferência na forma de XOS, e também se avaliou a produção de CNF, um nanomaterial emergente com inúmeras aplicações em diversos setores, como papel, têxteis e eletrônicos. Para selecionar a melhor condição de solubilização de hemicelulose na forma de XOS, as condições do processo hidrotérmicos foram avaliadas com planejamento experimental estatístico 23, com rotação do tipo estrela, a fim de analisar o efeito combinado de temperatura, tempo e concentração de ácido (H2SO4). A melhor condição experimental para produzir XOS com alto rendimento e seletividade foi a 182 °C durante 5,5 minutos e sem adição de ácido, obtendo um hidrolisado com recuperação de 43 % da xilana inicial na forma de XOS e apenas 2 % na forma de xilose. Um segundo tratamento hidrotérmico foi realizado com o objetivo de remover a xilana residual do bagaço tratado, de preferência na forma de XOS. Devido à alta recalcitrância do material, não foi possível encontrar uma condição experimental para obter alta seletividade para XOS no segundo pré-tratamento e, portanto, foi escolhido obter um hidrolisado rico em xilose, um produto que também possui diversas aplicações. As melhores condições experimentais para se obter um hidrolisado rico em xilose foram determinadas a 168 ° C durante 5,5 minutos e 1,01% m/m de H2SO4, obtendo-se uma recuperação de 36 % da xilana presente inicialmente no bagaço na forma de xilose e apenas 3 % na forma de XOS, sendo este um processo altamente seletivo para recuperação da xilana na forma monomérica. A fração sólida oriunda das etapas de extração da xilana foi deslignificada com NaOH e branqueada em duas etapas, com H2O2 em meio alcalino e com NaClO2 em meio ácido, obtendo pasta celulósica com alto teor de celulose (88,9% m/m de celulose). A polpa celulósica foi processada em um refinador de disco mecânico (SupermassColloider) para produzir celulose nanofibrilada (CNF-B). As propriedades morfológicas do CNF-B foram avaliadas e verificou-se que foi semelhante à nanocelulose de polpa Kraft (CNF-K), em relação as suas dimensões, produzida nas mesmas condições. Além disso, a produção do CNF-B consumiu cerca de um terço da energia necessária para obter o CNF-K. O balanço de massa final do processo mostrou uma alta recuperação dos carboidratos originais em produtos de alto valor agregado. A recuperação da xilana foi de cerca de 88% m/m, sendo 43% m/m de XOS e 36% m/m de xilose. O alto conteúdo recuperado dos coprodutos demonstra a alta seletividade das otimizações realizadas. Por fim, o processo obteve alta recuperação e conversão de celulose à CNF-B, com um rendimento de 88% m/m. / A pretreatment has been pursued to maximize the biomass components and achieve a high material´s valorization. Here, we report an integration of pathways, which have been effective to obtain three high value-added products in a biorefinery concept: XOS, xylose and cellulose nanofibrillated (CNF). The maximization of hemicellulose fraction was studied through hydrothermal extraction from sugarcane bagasse, preferably oligosaccharides (XOS) form, and it was also evaluated CNF production, an emerging nanomaterial with numerous applications in diverse sectors such as paper, textiles and electronics. To select the best condition of hemicellulose solubilization in the form of XOS, the hydrothermal process conditions were evaluated with statistical experimental design to analyze the combined effect of temperature, time and acid concentration (H2SO4). The best experimental condition to produce XOS with high yield and selectivity was at 182 ° C for 5.5 minutes and without acid addition, obtaining a hydrolysate with 75% w/w of XOS content, which corresponds to 43% w/w of the original xylan. A second hydrothermal treatment was performed with the aim of remove a residual xylan from treated bagasse, focusing in XOS form. Because of the high susceptibility of the material, it was not possible to find an experimental condition to achieve high selectivity for XOS in the second pretreatment and, therefore, it was chosen to obtain a hydrolyzate rich in xylose, a product with many applications as well. The best experimental conditions to the hydrolyzate system based in xylose was determined at 168 ° C for 5.5 minutes and 1.01% w/w H2SO4, obtaining a xylose\'s yields of 36% w/w (initial xylan). The solid fraction of the second hydrothermal step was deslignificated with NaOH and bleached in two steps, with H2O2 at alkaline medium and with NaClO2 at acid medium, obtaining cellulosic pulp with high cellulose content (88.9% w/w of cellulose). Cellulosic pulp was processed in a mechanical disc refiner (SupermassColloider) to produce fibrillated nanocellulose (CNF-B). The morphological properties of the CNF-B were evaluated, and it was found to be similar to Kraft pulp nanocellulose (CNF-K) produced at same conditions. Besides that, the production of CNF-B consumed about one third of the energy required to obtain CNF-K. CNF-B and CNF-K were also compared in terms of mean diameter and it was obtained 56.72 nm and 36.83 nm, respectively. The final mass balance of the process showed a high recovery of the original carbohydrates in means of high value-added product. The recovery of xylan was around 88%, being 43% w/w of XOS and 36% w/w of xylose. The high content recovered of the co-products demonstrate the high selectivity of the optimizations performed. Thus, this resulted in a high recovery and conversion of cellulose in the CNF-B with a yield of 88% w/w.