Coating Textiles With Antibacterial Nanoparticles Using the Sonochemical Techniqe

This chapter reviews the research on antibacterial functionalization of textiles with inorganic nanoparticles (Ag, MgO, Al2O3) by the sonochemical method. Sonochemistry is one of the most efficient techniques for the synthesis of nanosized materials, wherein ultrasonic waves in the frequency range of 20 kHz to 1 MHz serve as a driving force for chemical reactions. Sonochemical reactions are dependent on acoustic cavitation: the formation, growth, and explosive collapse of bubbles in irradiated liquids. Extreme conditions are developed when the bubbles collapse (temperature >5000 K, pressure >1000 atm, and cooling rates >109 K/sec), resulting in the breaking and forming of chemical bonds. The deposition of nanoparticles on the surface of natural and synthetic yarns and fabrics (wool, cotton, nylon, polyester) may be achieved using ultrasound irradiation. This process produces a uniform coating of nanoparticles on the textile surface with different functional groups. The coating can be performed by an in situ process, where the nanoparticles are formed and immediately propelled to the surface of the fabric. This approach was demonstrated with nanosilver. Alternatively, the sonochemical process can be used as a "throwing stone" technique, where previously synthesized nanoparticles are sonicated in the presence of the fabric. This process was shown with MgO and Al2O3 nanoparticles, which were propelled to the surface by microjets and adhered strongly to the textile without any additional binder. This phenomenon was explained because of the local melting of the substrate due to the high rate and temperature of nanoparticles propelled at the solid surface by sonochemical microjets. The activity of the fabric finishing with antibacterial nanoparticles was tested against Gram-negative and Gram-positive bacteria cultures. A significant bactericidal effect was demonstrated in both cases, even at a low concentration, below 1 wt.% of nanoparticles in the fabric.