Browsing by Author "Dufresne, Alain"

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    Absorption of siderite within a chemically modified poly(lactic acid) based composite material for agricultural applications
    (2018-05) García, Nancy L.; Fascio, Mirta; Errea, María Inés; Dufresne, Alain; Goyanes, Silvia Nair; D'Accorso, Norma Beatriz
    "Iron is an essential micronutrient for higher plants. Although abundant in most soils, Fe3+ is not available for plant uptake, because of its poor solubility. Ferrous sulfate is a fertilizer used for crops but, Fe2+ is readily oxidized to the plant-unavailable ferric form. It is therefore important to provide Fe2+ to plants, minimizing the loss of this nutrient by oxidation in Fe3+. This paper reports the development of a composite material consisting of a matrix (PLARAM), obtained by the chemical modification of poly(lactic acid), capable of retaining ferrous carbonate (siderite) within PLARAM (PLARAMFe). From the matrix, Fe2+ is released into the soil, enhancing its bioavailability. PLARAM and PLARAMFe films were obtained and their water wettability was studied. One side of the films was more hydrophilic than the other, turning this material attractive as a protective film when it is necessary to avoid loss of humidity."
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    Arapey sweet potato peel waste as renewable source of antioxidant: extraction, nanoencapsulation and nanoadditive potential in films
    (2021-01) Guerrero-León, Beatriz; Corbino, Graciela; Dufresne, Alain; Errea, María Inés; D'Accorso, Norma Beatriz; García, Nancy L.
    "In this work, the peel of Arapey Sweet Potato (Ipomoea batatas), a vegetable waste, was used as a source of phenolic compounds which are widely recognized as beneficial antioxidants for human health. The extract obtained from Ipomoea batatas exhibited an antioxidant activity significantly higher than many antioxidant agents reported in literature (476.96 mg of TROLOX mL-1), as well as good thermal stability. Nanocapsules of the extract coated with low molecular weight polylactic acid were prepared by the emulsification-solvent evaporation method and the nanoparticles obtained were characterized physical; thermal; and morphologically. An analysis of the variables that were investigated to increase the encapsulation efficiency is presented here. Besides, PLA films prepared via the solution-casting method exhibited good compatibility with the nanoparticles loaded with the antioxidant extract, as was evidenced by the uniform and stable dispersion of these particles in the films. Furthermore, an improvement of the mechanical properties of the PLA films due to the presence of the nanoparticles were clearly observed. Results reported here are encourage enough to propose the nanocapsules described in this work as additives or to be used immersed in films for controlled release of antioxidants, putting in value a vegetable waste."