The in situ synthesis and application of silver nanoparticles as an antimicrobial agent for cotton fibers

Authors: Fontenot, Krystal; Nam, Sunghyun; Condon, Brian

Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 12/22/2016
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The application of sliver (Ag) as an antimicrobial agent dates back to the 1800s. Silver systems release positively charged silver ions (Ag+), when in aqueous media, that disrupts negatively charged surfaces of bacterial membranes, thus resulting in bacterial death. Its antimicrobial utility is not limited to wound dressings, burn wounds, or wipes but also extends to sportswear, socks, etc. However, the use silver presents concerns due to its ability to leach out of systems; hence the need for durable silver systems. Silver nanoparticles (AgNP) have favorable antimicrobial properties since they have a smaller size, shape, a higher surface area, tunable chemical and physical properties, and are less likely to be resistant against different bacterial strains. Herein we propose the synthesis of silver nanoparticles embedded into the microfibril structure of cotton fibers, which yields a durable silver nanoparticle source. The in situ synthesis of silver nanoparticles on bleached and scoured cotton fibers (BSCF) required (i) swelling, (ii) ion exchange, and (iii) reduction to produce silver nanoparticle cotton fibers (AgNPCF), which are stable after a ten-month evaluation without any shifts in its absorbance wavelength or surface charge. Characterization of the untreated fibers (BSCF) and treated silver nanoparticle fibers required techniques such as ultraviolet visible spectroscopy, attenuated total reflectance infrared spectroscopy, field emission scanning electron microscopy, tunneling electron microscopy, and neutron activation. Both ultraviolet visible spectroscopy and attenuated total reflectance infrared spectroscopy indicated the AgNP were synthesized on the surface of the cotton fibers. Furthermore, surface analysis via infrared and microscopy testing of the AgNPCF indicated the AgNP are not abundantly present on the surface of the fibers and are present within the fibrillar structure. The AgNPCF have a concentration as high as 7000 ppm, as determined by neutron activation, and are durable after fifty accelerated launderings with an 8% reduction in silver nanoparticles. The laundered AgNP fibers (0, 5, 15, 30, 40, and 50X) were able to inhibit and eliminate Escherichia coli and Staphylococcus aureus bacterial strains and retain its antibacterial properties after accelerated launderings. The utility of the AgNP on cotton fibers for antibacterial applications is promising due to its durability and efficacy to eliminate bacterial strains after accelerated laundering.