RESUMEN
In this work, novel polysaccharide-based sorbents modified with plasma technologies are discussed. Plasma selectively modifies the surface properties by generating specific moieties, enhancing adsorption performance, and the physical-chemical properties of the material without modifying its bulk properties. Among plasma technologies, cold plasma is more suitable and energy-efficient, since thermal-sensitive materials could be modified using this technology. Besides, atmospheric-pressure plasma systems possess the required features to scale-up plasma technologies for surface modification of sorbents. Moreover, a big challenge is the semi-continuous operation to modify sorbents as it would decrease overall process costs. Due to its low-cost and extensive availability, polysaccharide-based sorbents are promising substrates for plasma-enhanced modification to develop highly efficient adsorbents. The development of polysaccharide-based materials includes modified cellulose, chitosan, or lignocellulosic materials with functionalities that increase adsorption capacity and selectivity towards a specific organic or inorganic pollutant.
RESUMEN
In order to provide a second economic life to agave fibers, an important waste material from the production of tequila, filaments based on polylactic acid (PLA) were filled with agave fibers (0, 3, 5, 10 wt%), and further utilized to produce biocomposites by fused deposition modeling (FDM)-based 3D printing at two raster angles (-45°/45° and 0°/90°). Differential scanning calorimetry, water uptake, density variation, morphology, and composting of the biocomposites were studied. The mechanical properties of the biocomposites (tensile, flexural, and Charpy impact properties) were determined following ASTM international norms. The addition of agave fibers to the filaments increased the crystallinity value from 23.7 to 44.1%. However, the fibers generated porous structures with a higher content of open cells and lower apparent densities than neat PLA pieces. The printing angle had a low significant effect on flexural and tensile properties, but directly affected the morphology of the printed biocomposites, positively influenced the impact strength, and slightly improved the absorption values for biocomposites printed at -45°/45°. Overall, increasing the concentrations of agave fibers had a detrimental effect on the mechanical properties of the biocomposites. The disintegration of the biocomposites under simulated composting conditions was slowed 1.6-fold with the addition of agave fibers, compared to neat PLA.