May 13, 2008
Sonochemical coating of silver nanoparticles on textile fabrics and their antibacterial activity
In the last decade sonochemistry has been shown to be an excellent method for depositing nanoparticles on solid flat and curved surfaces, such as polymers, ceramic bodies, glass, metals and textiles. This is due to microjets moving at very high speeds (>100 m/s) that are created as a result of the collapse of the acoustic bubble. These microjets stream towards the solid surfaces and throw the newly formed nanoparticles at them. At these high speeds they can melt soft surfaces and penetrate into them.
In a recently published paper, Gedanken and coworkers from Bar-Ilan University in Israel reported on the sonochemical deposition of silver nanoparticles on textile fabrics (nylon, polyester and cotton) and measured their antibacterial activity. The characterization studies included Rutherford back scattering (RBS) by Swiss collaborators (Haute Ecole Arc Ing´enierie, La Chaux-de-Fonds, Switzerland). Excellent antibacterial activity of the Ag–fabric composite against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) cultures was demonstrated.
The reported process was carried out by ultrasound radiation in a one-step reaction procedure, a process that does not involve any toxic chemicals. To the best of their knowledge, this is the first report on the deposition of silver nanoparticles on fabrics using the sonochemical method. The physical and chemical analysis has shown that nanocrystalline pure silver (80 nm in size) is finely dispersed on the fabric’s surface. The coating is stable on the fabric for at least 20 washing cycles in hot (40 °C) water. The mechanism of the strong adhesion of silver nanoparticles to the fibers is discussed in the paper.
The tensile force for the coated sample was ∼10% less than that of the non-impregnated fabric. The observed changes in the mechanical behavior of the yarn are within a range that is acceptable for standard cotton fabrics. According to this result, Gedanken and associates concluded that the sonochemical treatment of the fabric did not cause any significant damage to the structure of the yarn.
This research was supported by an EC grant to the LIDWINE Consortium through contract number NMP2-CT-2006-026741 of the 6th EC program.
About the author
Aharon Gedanken is a professor of chemistry at the Department of Chemistry, Bar-Ilan University. Dr Nina Perkas is senior researcher with Gedanken's group. Ilana Perelshtein and Guy Applerot are PhD students supervised by Gedanken. Geoffrey Guibert and Serguei Mikhailov are scientists in the Haute Ecole Arc Ing´enierie.