A multilevel factorial design of 2³ with 12 experiments was developed for the preparation of cellulose nanocrystals (CNC) from Agave tequilana Weber var. Azul bagasse, an agro-industrial waste from tequila production. The studied parameters were acid type (H₂SO₄ and HCl), acid concentration (60 and 65 wt% for H₂SO₄, 2 and 8N for HCl) temperature (40 and 60 °C for H₂SO₄, 50 and 90 °C for HCl), and hydrolysis time (40, 55 and 70 min for H₂SO₄; and 30, 115 and 200 min for HCl). The obtained CNC were physical and chemically characterized using dynamic light scattering (DLS), atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XDR) techniques. The maximum CNC yield was 90 and 96% for HCL and H₂SO₄, respectively, and the crystallinity values ranged from 88–91%. The size and morphology of A. tequilana CNC strongly depends on the acid type and hydrolysis time. The shortest CNC obtained with H₂SO₄ (65 wt%, 40 °C, and 70 min) had a length of 137 ± 68 nm, width 33 ± 7 nm, and height 9.1 nm, whereas the shortest CNC obtained with HCl (2 N, 50 °C and 30 min) had a length of 216 ± 73 nm, width 69 ± 17 nm, and height 8.9 nm. In general, the obtained CNC had an ellipsoidal shape, whereas CNC prepared from H₂SO₄ were shorter and thinner than those obtained with HCl. The total sulfate group content of CNC obtained with H₂SO₄ increased with time, temperature, and acid concentration, exhibiting an exponential behavior of $C_{SG}=a{e}^{bt}$.

This study examines the effect of particle size and wood flour content on the properties of polystyrene filled with white oak flour. Wood-plastic ratios 10:90, 30:70 and 50:50% (wt/wt) and particle size 40, 50, 65 and 100 mesh were used. Tensile, bending and impact bending strength as well as the melt flow index were evaluated. Additionally, composite density and water absorption capacity were also tested. Scanning electronic microscopy revealed good adhesion between wood particles and polystyrene. Results show that mechanical properties are strongly influenced by wood flour content and particle size. A reduction in tensile module, elongation and deflection were observed, however, the bending module was increased. Impact strength increased with particle size and content. Melt flow index values are reduced with the increasing amount of filler content while water absorption increases with the amount of wood particles.

To promote osteointegration, bioactive cuttlebone particles containing collagen were used to fill an acrylic cement, varying filler concentration (0–50 wt%). Cuttlebone was characterized by X-ray d...

In this work, cellulose nanocrystals (CNCs), bleached cellulose nanofibers (bCNFs), and unbleached cellulose nanofibers (ubCNFs) isolated by acid hydrolysis from Agave tequilana Weber var. Azul bagasse, an agro-waste from the tequila industry, were used as reinforcements in a thermoplastic starch matrix to obtain environmentally friendly materials that can substitute contaminant polymers. A robust characterization of starting materials and biocomposites was carried out. Biocomposite mechanical, thermal, and antibacterial properties were evaluated, as well as color, crystallinity, morphology, rugosity, lateral texture, electrical conductivity, chemical identity, solubility, and water vapor permeability. Pulp fibers and nanocelluloses were analyzed via SEM, TEM, and AFM. The water vapor permeability (WVP) decreased by up to 20.69% with the presence of CNCs. The solubility decreases with the presence of CNFs and CNCs. The addition of CNCs and CNFs increased the tensile strength and Young’s modulus and decreased the elongation at break. Biocomposites prepared with ubCNF showed the best tensile mechanical properties due to a better adhesion with the matrix. Images of bCNF-based biocomposites demonstrated that bCNFs are good reinforcing agents as the fibers were dispersed within the starch film and embedded within the matrix. Roughness increased with CNF content and decreased with CNC content. Films with CNCs did not show bacterial growth for Staphylococcus aureus and Escherichia coli. This study offers a new theoretical basis since it demonstrates that different proportions of bleached or unbleached nanofibers and nanocrystals can improve the properties of starch films.