Browsing by Author "Zalazar, Cristina"

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    Microparticles based on ionic and organosolv lignins for the controlled release of atrazine
    (Journal of Hazaourdos Materials, 2018-07-02) Taverna, María E.; Busatto, Carlos Alberto; Lescano, Maia Raquel; Nicolau, Verónica V.; Zalazar, Cristina; Meira, Gregorio; Estenoz, Diana
    Lignins are natural polymers of the lignocellulosic biomass. Nowadays, there is a growing interest in developing value-added products based on lignins due to their renewability, low cost and abundance. In this work, lignin microspheres from organosolv and ionic isolation processes were prepared for the controlled release of atrazine. Microspheres were prepared by the solvent extraction/evaporation technique. The controlled release of atrazine from organosolv and ionic lignins microparticles was studied in water. Mobility experiments were performed in an agricultural soil from Argentina. The results showed that microparticles prepared using dichloromethane as the dispersed phase were spherical, while lignins dispersed in ethyl acetate produce irregular microparticles. Organosolv lignin microparticles presented higher encapsulation efficiency for all herbicide loads. About 98% and 95% of atrazine was released in 24 and 48h approximately from organosolv and ionic lignin microparticles, respectively. The release profiles of atrazine from both lignin microparticles were not affected by the herbicide load. Atrazine mobility experiments in soil showed that about 80% of free atrazine was leached in 37 days, while 65.0% and 59.7% of the herbicide was leached from ionic and organosolv lignin microparticles, respectively. Thus, atrazine-loaded microparticles could reduce leaching compared to a commercial formulation of free atrazine.
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    Preparation and Characterization of Lignin Microparticles-in-Alginate Beads for Atrazine Controlled Release
    (2019-09-21) Busatto, Carlos Alberto; Taverna, María E.; Lescano, Maia Raquel; Zalazar, Cristina; Estenoz, Diana
    The use of lignin as polymeric matrices for controlled release systems in agriculture is a promising alternative for its reval-orization. In this work, diferent atrazine delivery systems were studied. Lignin derived from ionic isolation was used for the preparation of atrazine-loaded microparticles by the solvent extraction/evaporation and microfuidic techniques. Micropar-ticles were also encapsulated in sodium alginate beads. Lignin microparticles prepared by microfuidics presented a larger particle size, higher encapsulation efciency and a narrow size distribution. The in vitro release of atrazine was evaluated in water. Atrazine release from microparticles prepared by the solvent extraction/evaporation technique showed a signifcant burst release, and this efect was reduced by incorporating microparticles within alginate beads. In addition, the phytotoxicity of the systems was evaluated employing Lactuca sativa seeds. The phytotoxicity results showed that lignin-based formula- tions are safe according to the parameters evaluated, in contrast with commercial atrazine that resulted phytotoxic.