Submitted to: American Association of Textile Chemists and Colorists Journal of Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/18/2018
Publication Date: 5/1/2019
Citation: Fontenot, K.R., Nam, S., French, A.D., Condon, B.D. 2019. Stability and antibacterial assessment of copper nanoparticles dispersed on cotton fabrics. American Association of Textile Chemists and Colorists Journal of Research. 6(3):8-19. https://doi.org/10.14504/ajr.6.3.2.
Interpretive Summary: The utility of copper nanoparticles provides beneficial and effective antibacterial properties however, its application in general is facing challenges in terms of stability as their use may be limited by a lack of stability due to oxidation, hence the need for stabilized copper antibacterial textiles. Several previous studies focused on preventing oxidation using stabilizing polymers or ligands. On the other hand, studies show that cotton fibers and the reducing agent ascorbic acid serves as stabilizers for nanoparticles. Therefore, cotton non-woven fabrics were used for the in situ synthesis of copper nanoparticles using a modification of a previously reported method. Therefore, the stability and antimicrobial efficacy of copper nanoparticles synthesized on nonwoven cotton fabrics were evaluated as antibacterial wipes. Characterization and evaluation of the copper nanoparticle fabrics indicated differences in fabric dimensions, absorbance properties, surface morphology, which reflected the formation of nanoparticles and stable fibers due to a negative surface charge, the electrostatic interactions copper forms with oxygen, and to the absence of shifts in its lambda max values. The copper nanoparticle fabrics inhibited both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) according to the AATCC-100 method, which indicates the fabrics ability to exhibit a broad-spectrum antibacterial activity. Therefore, the utility of the prototype copper nanoparticle fabrics proposed herein for antibacterial wipe applications shows promise due to their stability and ability to prevent bacterial contamination and surface sterility. This study presented a proof-of-concept of using stable copper nanoparticle fabrics as an antibacterial wipe prototype.
Technical Abstract: The direct synthesis of copper nanoparticles onto cotton textiles faces challenges due to the oxidation of the nanoparticles, which is controlled by capping agents or stabilizers. However, studies show that both the cotton fiber can serve as a stabilizing agent in addition to the use of ascorbic acid, which prevents the oxidation of copper nanoparticles. In this study, copper nanoparticles were synthesized in situ on cotton fabrics yielding a copper nanoparticle deposition of 78 mgg-1, in which the cotton fiber and ascorbic acid stabilized and prevented the oxidation of the copper nanoparticles as reflected after a six-month storage at ambient conditions without any changes in absorbance wavelength, surface charge, or color of the fabrics. Changes in the fabric characteristics for copper alkali fabrics and copper nanoparticle fabrics compared to cotton fabric, i.e., revealed differences in fabric dimensions, absorbance properties, and surface morphology, which supports the presence of the copper-cellulose complex. X-ray diffraction patterns revealed the presence of cellulose I and some cellulose II structure, a smaller crystal size, and the presence of metallic copper. The cotton and copper alkali fabrics showed high wettability and hydrophilic properties in contrast to hydrophobic copper nanoparticle fabrics. However, the copper nanoparticle fabrics had an effective antibacterial activity against Escherichia coli and Staphylococcus aureus. The utility of the copper nanoparticle fabrics proposed herein for antibacterial wipes or infection resistant fabrics shows promise due to their stability and ability to inhibit bacterial contamination.