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Comprehensively introduces readers to the production, modifications, and applications of nanocellulose This book gives a thorough introduction to the structure, properties, surface modification, theory, mechanism of composites, and functional materials derived from nanocellulose.

The current structural models of the cellulose microfibril as well as its mechanical and thermal properties are reviewed. The cellulose microfibril can be considered as a single thin and long crystalline entity with highly anisotropic physical properties. The contribution and limit of different methods employed such as electron microscopy, infrared spectroscopy, X-ray scattering and diffraction, solid state nuclear magnetic resonance spectroscopy, and molecular modeling are also discussed.

Eichhornia crassipes is an invasive aquatic plant that reduces oxygen availability, posing a threat to aquatic ecosystems. This was evidenced in the cooling lagoons of the Paipa Thermoelectric Power Plant in Boyacá, Colombia. Due to its low lignin content (~15%), this plant does not require rigorous treatments for utilization, which allows exploring its potential as a precursor in obtaining value-added products while contributing to the conservation of affected aquatic ecosystems. The objective of this study was to evaluate the growth of kefir tibicos in a culture medium with hydrolysates of E. crassipes obtained from sequential and simultaneous pretreatments with cellulase and the inclusion of activated charcoal suspensions, using sucrose as a co-substrate. All processes were monitored with measurements of soluble solids, reducing sugars, acidity, and pH. Finally, the kefir tibicos were characterized using Fourier-transform infrared spectroscopy and X-ray diffraction, and the thermal properties of dextran were identified through differential scanning calorimetry and thermogravimetric analysis. According to the results, the difference in exopolysaccharide production between the sequential and simultaneous applications of cellulase was less than 10%. However, the inclusion of activated charcoal increased the difference to 22.8% and revealed that insoluble dextran could be applied as a matrix for the in situ immobilization of particles during the microorganism growth stage. Eichhornia crassipes es una planta acuática invasora que genera disminución en la disponibilidad de oxígeno, representando una amenaza para los ecosistemas acuáticos. Esto se evidenció en las lagunas de enfriamiento de la Central Termoeléctrica de Paipa, en Boyacá, Colombia. Debido a su bajo contenido de lignina (~15 %), esta planta no requiere tratamientos rigurosos para su aprovechamiento, lo que permite explorar su potencial como precursora en la obtención de productos de valor agregado, al tiempo que se contribuye a la conservación de ecosistemas acuáticos afectados. El objetivo de este estudio fue evaluar el crecimiento de tíbicos de kéfir en un medio de cultivo con hidrolizados de E. crassipes, obtenidos a partir de pretratamientos secuenciales y simultáneos con celulasa y de la inclusión de suspensiones de carbón activado, utilizando sacarosa como cosustrato. Todos los procesos se monitorearon con mediciones de sólidos solubles, azúcares reductores, acidez y pH. Por último, los tíbicos fueron caracterizados mediante espectroscopia infrarroja por transformada de Fourier y difracción de rayos X, y se identificaron las propiedades térmicas del dextrano mediante calorimetría diferencial de Barrido y análisis termogravimétrico. De acuerdo con los resultados, la diferencia en la producción de exopolisacárido entre la aplicación secuencial y simultánea de celulasa fue inferior al 10 %. Sin embargo, la inclusión de carbón activado hizo que la diferencia se incrementase hasta 22.8 % y reveló que el dextrano insoluble podría aplicarse como matriz para la inmovilización de partículas in situ en la etapa de crecimiento de los microorganismos.

An up-to-date and comprehensive overview summarizing recent achievements, the state of the art, and trends in research into nanocellulose and cellulose nanocomposites. Following an introduction, this ready references discusses the characterization as well surface modification of cellulose nanocomposites before going into details of the manufacturing and the self-assembly of such compounds. After a description of various alternatives, including thermoplastic, thermosetting, rubber, and fully green cellulose nanocomposites, the book continues with their mechanic and thermal properties, as well as crystallization and rheology behavior. A summary of spectroscopic and water sorption properties precedes a look at environmental health and safety of these nanocomposites. With its coverage of a wide variety of materials, important characterization tools and resulting applications, this is an essential reference for beginners as well as experienced researchers.

Bacterial cellulose films were combined with glycerol and chitosan to improve the UV-barrier and mechanical properties. In part 1, the moisture content and mechanical properties (tensile and puncture properties) were analysed by response surface methodology. The calculated values of the mechanical properties were in the range of 1.23-39.28 MPa for tensile strength, 2.28-25.34% for percentage of elongation, 11.72-1579.59 MPa for Young's modulus, 0.22-1.92 MJ/m 3 for toughness, 43.74-1067.35 g for burst strength and 0.39-3.12 mm for distance to burst. In general, a plasticizing and a reinforcing effect on the bacterial cellulose films was observed by glycerol and chitosan addition. Glycerol provided adhesive properties, which can be an advantage for application on foods, such as fruit or vegetables, as a wrapping material.

Bacterial cellulose films synthesized by Komagataeibacter xylinus were combined with glycerol and chitosan to obtain composite films with improved UV-barrier. In part 2, the interaction among the compounds was analyzed by scanning electron microscopy, UV-Vis and FT-IR spectra, thermogravimetry, and differential scanning calorimetry. The water permeability, water solubility and water retention capacity were analyzed by response surface methodology. The optical properties indicated that glycerol and chitosan improved the UV-barrier properties, obtaining average transmittance values in the UV regions below 5.15%. This fact opens multiple possibilities for applications in foods and products sensitive to sunlight radiation. Hence, these properties would facilitate the application of BC-glycerol-chitosan films on fresh food, with high moisture content and susceptible to oxidation by the sunlight radiation. In addition, the thermal properties of the films showed that they could be applied in heat-treated foods at temperatures until 135°C.

Cellulose is a major constituent of papers made from plant fibers and combustible component of non-food energy crops. An ideal reference for scientists in natural and synthetic polymer research, this book applies basic biology as well as polymer and sugar chemistry to the study of cellulose. It provides key requirements for understanding the complex structure and biosynthesis of cellulose and its dissolution into new solvents. Cellulose Science and Technologyalso clarifies the enzymatic hydrolysis of cellulose leading to simple sugars that can be fermented into bioethanol. It examines the bacteria capable of breaking down cellulose and the derivatives that result from the process.

The chestnut shell from the Amazon region shared between Colombia, Brazil, and Perú is an abundant residue of the walnut used for obtaining food and cosmetic products. This residue is not yet usable due to the lack of knowledge of its properties and the environmental impact generated by its treatment through methods such as mercerization. This work presents the results of the characterization of Amazon chestnut shell residues treated by two methods, mercerization with NaOH solution and intense plasma discharge (Glow Discharge Plasma), in a reactor with argon gas in a 0,3-bar vacuum and discharge conditions of 80 mA and 600 s. The microstructural, morphological, topographic, and nanomechanical changes of the chestnut residues without treatment and with the two proposed treatments were evaluated by means of the µRaman, scanning electron microscopy, and atomic force microscopy techniques. The results showed the effectiveness of the plasma method over the mercerization method at obtaining more crystalline cellulose structures due to the reduction of hemicellulose, lignin, and the aqueous phase of walnut shell waste.

Physical, chemical, and biological properties of wood depend largely on the properties of cellulose, noncellulosic polysaccharides, and lignin, and their assembly mode in the cell wall. Information on the assembly mode in the main part of the ginkgo tracheid wall (middle layer of secondary wall, S2) was drawn from the combined results obtained by physical and chemical analyses of the mechanically isolated S2 and by observation under scanning electron microscopy. A schematic model was tentatively proposed as a basic assembly mode of cell wall polymers in the softwood tracheid as follows: a bundle of cellulose microfibrils (CMFs) consisting of about 430 cellulose chains is surrounded by bead-like tubular hemicellulose-lignin modules (HLM), which keep the CMF bundles equidistant from each other. The length of one tubular module along the CMF bundle is about 16 +- 2 nm, and the thickness at its side is about 3 - 4 nm. In S2, hemicelluloses are distributed in a longitudinal direction along the CMF bundle and in tangential and radial directions perpendicular to the CMF bundle so that they are aligned in the lamellae of tangential and radial directions with regard to the cell wall. One HLM contains about 7000 Csub(6)-Csub(3) units of lignin, and 4000 hexose and 2000 pentose units of hemicellulose.

Este documento describe un miniproyecto de cinco semanas para la enseñanza de la química y la sostenibilidad. Las actividades incluyen la producción de películas poliméricas sostenibles a partir de quitosano y celulosa y su aplicación en la adsorción de colorantes alimentarios. Se cubren las habilidades y conceptos normalmente presentes en los cursos prácticos de química: uso de balanzas, cristalería volumétrica, técnicas de dilución, técnica de espectrofotometría UV-Vis y cálculos estequiométricos. Además, se presentan a los estudiantes los pasos habituales de investigación y desarrollo de nuevos materiales utilizados en los procesos de adsorción.