Biopolymer nanofiber doped with nanospinels by electrospinning and microbiological assays

Aim of this work was investigated the change in physical-chemical properties of biopolymer (poly(lactic acid)(PLA)) nanofiber doped with magnetic nanospinels and study of antimicrobial activity of these matrix for a possible use as fungical or carrier drug used in the organic farming. The spinel nanoparticles (Ni0.5Fe2.5O4) were synthesized by Sol-gel method and the incorporation to polymeric matrix was performed by impregnation method and nanofiber synthetized by electrospinning. Nanoparticles were characterized by FESEM, DRX and SQUID. PLA was characterized by SEM and DSC and nanoparticles supported on biopolymer were characterized by DSC and were realized bioassays (antibiograms in font to Fusarium sp). Through powder X-rays, the average crystalline size of nanoparticles was determined using Scherrer's formula and the network parameters by FullProf suite, via Rietveld's method. The average size measurements were between 5 nm and 35 nm. Magnetic susceptibility measurements were performed to determine the blocking temperature of the nanoparticles, the compounds present magnetic irreversibility at room temperature. The nanofiber characterization by SEM showed that all fibers have nanometric size. In addition, bioassays of nanoparticles showed an inhibitory activity for different concentration of nanoparticles, by contrast in biopolymer nanofiber doped with nanospinels no showed activity in a preliminary test. These results suggest a possible use of nanofibers with a higher concentration of nanoparticles as organic fungicides.