Search

Composite films with Ag nanoparticles, which are active in biological applications such as biosensors, wound healing and cancer treatment, have been obtained in recent years on a blend consisting of polylactic acid and polyethylene glycol, which has the feature of working shape recovery. The characteristic signals of PLA and PEG were determined by making functional group analyses with attenuated total reflection infrared spectroscopy (ATR-IR) of polymer composite films obtained by the solution casting method. From the results of thermal analysis with thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), it can be interpreted that Ag nanoparticle increases the initial decomposition temperature (Ti) of the polymer blend, that is, increases its thermal stability. The use of a high PEG ratio showed that the droplets in the scanning electron microscopy (SEM) images of the blend were large, while it was observed that these droplets were almost filled with the increasing Ag nanoparticle ratio. The characteristic XRD diffraction angles of Ag nanoparticles were determined more clearly in the composite containing 20% Ag at 2θ= 38.1°, 44.5°, 64.6° and 77.3°. Finally, when the antimicrobial activities of the composites on L. Monocytogenes, C. perfringens, P. aeruginosaand E. coliO: 157 bacteria are examined, the antimicrobial activity with the highest Ag percentage proves the antimicrobial property of Ag.

This study aimed to synthesize magnetic Fe3O4nanoparticles treated with Polygonum cognatumand then evaluate its thermal, magnetic, and antimicrobial activity.The surface morphology of MNP was characterized by SEM and image mapping. The XRD measurements were carried out to calculate the crystallite size of the sample, and the cubic structure of the iron oxide nanoparticles was identified in the XRD pattern. FT-IR spectroscopy confirmed that the bioactive molecules in the plant structure are attached to the MNP surface. Thermal analysis showed that the plant extract reduced the thermal stability of pure MNP. From the magnetization curves obtained by VSM, it was seen that MNP treated with the plant has superparamagnetic properties and its saturation magnetization value is 26.073 emu/g. Besides, the antimicrobial effects of MNP, plant extract, and MNP treated with plant extract against Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Bacillus megaterium, and Candida albicanswere examined.