ABSTRACT
We have reported a novel in situ synthesis protocol for silver nanoparticles onto cotton fabrics. Here, cotton fabric immersed in silver nitrate solution is autoclaved at 15 psi, 121 degrees C for 15 min. At this temperature and pressure, the aldehyde terminal of starch (residual size material on cotton fabric) reduced the silver nitrate to silver metal and simultaneously stabilized the nanoparticles on fabric itself. The UV-visible absorption spectrum of both cotton fabrics and bath solution showed a typical absorption peak at 420 nm corresponding to the surface plasmon resonance of silver nanoparticles. With the help of transmission electron micrographs, the average size of the dislodged silver nanoparticles in water is calculated to be 20.9 +/- 13.7 nm. This silver nanoparticles impregnated cotton fabrics showed excellent antibacterial activity against Staphylococcus aureus and bacteriostasis activity against Klebsiella pneumoniae. Also, silver nanoparticles impregnated fabrics expressed significant UV-protection capability in comparison with the untreated fabrics.
Subject(s)
Cotton Fiber , Klebsiella pneumoniae/drug effects , Nanostructures/administration & dosage , Nanostructures/chemistry , Silver/chemistry , Silver/pharmacology , Staphylococcus aureus/drug effects , Anti-Bacterial Agents/administration & dosage , Crystallization/methods , Klebsiella pneumoniae/cytology , Macromolecular Substances/chemistry , Materials Testing , Molecular Conformation , Nanostructures/ultrastructure , Nanotechnology/methods , Particle Size , Staphylococcus aureus/cytology , Surface PropertiesABSTRACT
Stable silver nanoparticles have been synthesized by using soluble starch as both the reducing and stabilizing agents; this reaction was carried out in an autoclave at 15 psi, 121 degrees C for 5 min. Nanoparticles thus prepared are found to be stable in aqueous solution over a period of three months at room temperature (approximately 25 degrees C). The size of these nanoparticles was found to be in the range of 10-34 nm as analyzed using transmission electron micrographs. The X-ray diffraction analysis revealed the face-centred cubic (fcc) geometry of silver nanoparticles. Iodometric titration confirmed the entrapment of silver nanoparticles inside the helical amylose chain. These silver nanoparticles embedded in soluble starch produced a typical emission peak at 553 nm when excited at 380 nm. The use of environmentally benign and renewable materials like soluble starch offers numerous benefits of eco-friendliness and compatibility for pharmaceutical and biomedical applications.
