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La Agenda 2030 para el desarrollo sostenible impone grandes desafíos a todas las naciones. Dentro de los programas de formación profesional, asumir estos grandes retos, requieren prácticas pedagógicas que integren técnicas, métodos y metodologías disruptivas. En este sentido, se propone el diseño de secuencias didácticas para la formación de competencias que permitan la comprensión del desarrollo sostenible y la ciudadanía global. A través de las fases de identificación, diseño y propuesta instruccional, se plantea una investigación con enfoque cualitativo, alcance descriptivo y diseño de teoría fundamentada que define las matrices de seguimiento, ejecución y evaluación en una intervención pedagógica. Desde ahí, se concluye que, en el escenario de la Institución Universitaria Pascual Bravo, se aportan iniciativas donde se promueve la libertad e igualdad para el desarrollo sostenible, en términos de estilos de vida, prácticas ciudadanas y generación de cultura en la formación profesional.

It is a well-known fact that polymeric cellulose mols. are considered as versatile materials with respect to chem. modifications when compared to synthetic polymeric counterparts. Hydroxyl groups are readily able to undergo various derivatisation procedures both in aq. and in non-polar org. solvent environments. The identical versatility and effortless modification strategies are often claimed to apply for nanocellulosic materials as well due to the numerous and accessible hydroxyl groups located directly on the surfaces of fibrils or crystals prone to further functionalisations. In practice, nanocellulosic materials unfortunately often defy the facile chem. modification routes involving covalent binding. This presentation discusses the nanocellulose dispersion related challenges, which frequently result in severe agglomeration tendency of fibrils or crystals thus lowering the yield and degree of surface substitution of the endproducts. Simultaneously the precious nanoscaled fine structure is irreversibly lost. Furthermore, the purifn. processes for the modified nanocellulose grades are not trivial at all since nanoscaled materials prevent the conventional filtration and centrifugation procedures. These aspects are exemplified using simple chem. modification strategies based on APTES-chem. or pNIPAM grafting. Alternative modification strategy involving the direct interfacial modification of the already assembled nanocellulosic structures is proposed to overcome the aforementioned challenges.

The integration of reinforcing materials in composites with synthetic polymers has gained increased attention in recent years, especially in the area of nanocomposites. Most of the efforts in this respect have focused on inorganic reinforcing agents and mostly by using the casting method. Recently, the developments based on renewable materials have become increasingly popular because of the need for finding alternatives to nonrenewable fossil carbon resources. Among such materials, readily available cellulose nanocrystals (CNs) have attracted great interest because of their availability, renewability, biodegradability, and excellent mechanical properties. Furthermore, CNs are relatively easy to produce and are much less expensive than most of the particles currently used for reinforcement purposes. An additional advantage of CNs and “lignocellulosics” fillers compared to equivalent inorganics include high specific strength, surface reactivity, and the option of surface modification to give better compatibility with the matrix materials. On the other hand, the development of fibers with diameters in the micro- and nanoscale has gained vitality, because of the unique properties that they present, for example, their very high surface area-to-volume ratio. This characteristic along with the remarkable flexibility in surface functionalities and superior mechanical performance determine their importance in many fields, such as medicine, pharmacy, and nanocomposites manufacture. The production of fibers by using the electrospinning technique, which can be used in the spinning of either synthetic or natural polymer solutions, polymer alloys, and polymers filled with nanoparticles, metals, and so on, is a fascinating platform that has been utilized since several decades ago. Electrospinning is carried out with the help of electrostatic forces and allows manufacture of continuous nanofibers. Electrospun nonwoven mats provide very porous and interconnected structures, with an overall high surface area compared to regular textiles. After briefly discussing the electrospinning process, this chapter introduces the subject of CNs as the dispersed reinforcing phase in green composite fibers. Finally, results from our research with nano- and microfiber composites are discussed using some examples of interest for green applications. Fil: Peresin, María Soledad. North Carolina State University; Estados Unidos Fil: Zoppe, Justin O. North Carolina State University; Estados Unidos Fil: Vallejos, María Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentina Fil: Habibi, Youssef. North Carolina State University; Estados Unidos Fil: Hubbe, Martin A.. North Carolina State University; Estados Unidos Fil: Rojas, Orlando J.. North Carolina State University; Estados Unidos

The unique properties of nanofibrillated cellulose make it a strong candidate for many applications such as composites, construction, porous and functional materials, among others. Most of these applications require chemical modification, either to achieve better compatibility with the matrix or to provide resistance to ambient conditions; case in which might be preferable to directly modify the surface of nanocellulose films. During film formation, accumulations of airborne contamination on the film surface are likely to hamper potential sites for chemical reaction. Thus, an effective activation of the surface is essential in order to achieve desired levels of modification. In this paper, a strategy to control and enhance the reactivity of nanocellulose film surfaces is discussed. The success of such surface activation is demonstrated by surface modification and analyzed using a set of surface sensitive methods such as atomic force microscopy, contact angle measurements and X-ray photoelectron spectroscopy.

In this contribution, a novel and up-scalable technology to produce plastic-like nanocellulosic films will be discussed. A large-scale film manufacture method was developed, based on traditional solvent casting of the nanofibrillated cellulose (NFC) suspension onto a plastic substrate, enabling also roll-to-roll film production. By the technology here presented, several meters of plastic-like films made of pure NFC with smooth and defect-free surfaces are being produced. Furthermore, the surface of the film has been modified, increasing even further areas of application of this material. An overview of the production and surface modification and of these plastic-like films will be delivered, together with a discussion of the most significant results and potential applications.