Electrospun alginate nanofibres impregnated with silver nanoparticles: Preparation, morphology and antibacterial properties.

Silver nanoparticles are amongst the most valuable nanoparticles with interesting properties, such as a non-toxic nature and high antibacterial efficiency, making them applicable for tissue scaffold, protective clothing and wound dressing. In this study, silver nanoparticles (AgNPs) have been synthesized using chitosan as reducing and stabilizing agent. The formation of silver nanoparticles was confirmed by UV-vis, and the TEM showed that different shapes were obtained depending on the heating duration. The chitosan/AgNPs was coated onto an electrospun alginate membrane to produce stable polyelectrolyte complex (PEC) nanofibre composites with high antibacterial efficiency. These composites were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). AgNPs were successfully impregnated into the PEC nanofibre composite, while there was complexation between the electrospun alginate and the chitosan/AgNPs composite. PEC demonstrated a good antibacterial activity against both gram negative and gram positive bacteria with acceptable water vapour transmission within the range required for the treatment of injuries or wounds.

Study of Sago starch-CdS nanocomposite films: fabrication, structure, optical and thermal properties.

A synthetic procedure for the preparation of nanocomposite films of sago starch and CdS nanoparticles was introduced. The films were characterized using optical, structural, and thermal techniques. The formation of nanostructured CdS in the starch matrix was confirmed by a blue shift in the onset of absorption in the UV-VIS spectra of the nanocomposites. The average size of the nanoparticles varied from 3.6 to 5 nm, depending on the initial concentration of cadmium acetate during the nanocomposite preparation. Fluorescence measurements of the sago-CdS nanocomposite film showed broad emission in the orange-red part of the spectrum. DSC and TGA analyses revealed significant effects of CdS nanoparticles on the thermal properties of the starch matrix.