Browsing by Author "Balladares Pugo, Samantha Estefania"

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    Síntesis de nanocompuestos de quitosano incorporando nanopartículas de cobre y extracto de canela mediante gelificación iónica y secado por aspersión
    (Universidad de Cuenca. Facultad de Ciencias Químicas, 2026-02-11) Balladares Pugo, Samantha Estefania; Guachichullca Guambaña, Astrid Carolina; Vanegas Peña, María Eulalia
    Fungal diseases caused by pathogens such as Fusarium spp. represent a significant threat to Ecuadorian agriculture, generating economic losses in important crops, where conventional management through fungicides has caused microbial resistance, environmental contamination, and adverse effects on beneficial soil organisms, evidencing the need for sustainable alternatives with antimicrobial efficacy and low environmental impact. This study developed and evaluated chitosan nanocomposites incorporating copper nanoparticles (CuNPs) and cinnamaldehyde through ionic gelation and spray drying, where Cu-NPs were synthesized by solvothermal method with ethylene glycol, obtaining particles of 25-80 nm with 36.4 % copper (XRF); on the other hand, cinnamaldehyde was incorporated as a natural extract from Amazonian cinnamon, preparing the composites in three combinations: chitosan/Cu-NPs, chitosan/cinnamaldehyde, and chitosan/cinnamaldehyde/Cu-NPs using both techniques. Characterization by atomic force microscopy (AFM) revealed microspheres for ionic gelation and porous structures for spray drying, while XRF analysis confirmed effective copper incorporation (3.66-5.61 % gelation; 5930-7710 ppm spray drying); release assays in acidic medium revealed differentiated profiles: ionic gelation (50 % w/w Cu-NPs) with sustained release and spray drying (10 % w/w Cu-NPs) with rapid initial release. Mathematical modeling using Higuchi and Korsmeyer-Peppas identified quasi-Fickian diffusion for ionic gelation (n=0.19-0.30) and anomalous transport for Cu-NPs in spray-dried triple composite (n=0.51), evidencing simultaneous contribution of diffusion and erosion, with coefficients R²>0.90 and CV<10 % validating the reproducibility and applicability of these composites as dual-release biofungicides for sustainable control of agricultural pathogens