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With increasingly frequent highly infectious global pandemics, the textile industry has responded by developing commercial fabric products by incorporating antibacterial metal oxide nanoparticles, particularly copper oxide in cleaning products and personal care items including antimicrobial wipes, hospital gowns and masks. Current methods use a surface adsorption method to functionalize nanomaterials to fibers. However, this results in poor durability and decreased antimicrobial activity after consecutive launderings. In this study, cuprous oxide nanoparticles with nanoflower morphology (Cu2O nanoflowers) are synthesized in situ within the cotton fiber under mild conditions and without added chemical reducing agents from a copper (II) precursor with an average maximal Feret diameter of 72.0 ± 51.8 nm and concentration of 17,489 ± 15 mg/kg. Analysis of the Cu2O NF-infused cotton fiber cross-section by transmission electron microscopy (TEM) confirmed the internal formation, and X-ray photoelectron spectroscopy (XPS) confirmed the copper (I) reduced oxidation state. An exponential correlation (R2 = 0.9979) between the UV-vis surface plasmon resonance (SPR) intensity at 320 nm of the Cu2O NFs and the concentration of copper in cotton was determined. The laundering durability of the Cu2O NF-cotton fabric was investigated, and the superior nanoparticle-leach resistance was observed, with the fabrics releasing only 19% of copper after 50 home laundering cycles. The internally immobilized Cu2O NFs within the cotton fiber exhibited continuing antibacterial activity (≥99.995%) against K. pneumoniae, E. coli and S. aureus), complete antifungal activity (100%) against A. niger and antiviral activity (≥90%) against Human coronavirus, strain 229E, even after 50 laundering cycles. [ABSTRACT FROM AUTHOR]

Greige cotton (unbleached cotton) is an intact plant fiber that retains much of the outer cotton fiber layers. These layers contain pectin, peroxidases, and trace metals that are associated with hydrogen peroxide (H2O2) generation during cotton fiber development. When greige cotton is subjected to a nonwoven hydroentanglement process, components of the outer cotton fiber layers are retained. When hydrated, this fabric can generate H2O2 (5-50 micromolar). This range has been characterized as inducing accelerated wound healing associated with enhanced cell signaling and the proliferation of cells vital to wound restoration. On the other hand, H2O2 levels above 50 micromolar have been associated with bacteriostatic activity. Here, we report the preparation and hydrogen peroxide activity of copper/ascorbate formulations, both as adsorbed and in situ synthesized analogs on cotton. The cooper/ascorbate-cotton formulations were designed with the goal of modulating hydrogen peroxide levels within functional ranges beneficial to wound healing. The cotton/copper formulation analogs were prepared on nonwoven unbleached cotton and characterized with cotton impregnation titers of 3-14 mg copper per gram of cotton. The copper/ascorbate cotton analog formulations were characterized spectroscopically, and the copper titer was quantified with ICP analysis and probed for peroxide production through assessment with Amplex Red. All analogs demonstrated antibacterial activity. Notably, the treatment of unbleached cotton with low levels of ascorbate (~2 mg/g cotton) resulted in a 99 percent reduction in Klebsiella pneumoniae and Staphylococcus aureus. In situ synthesized copper/ascorbate nanoparticles retained activity and did not leach out upon prolonged suspension in an aqueous environment. An assessment of H2O2 effects on fibroblast proliferation are discussed in light of the copper/cotton analogs and wound healing. [ABSTRACT FROM AUTHOR]

Countless hours of research and studies on triazine, phosphonate, and their combination have provided insightful information into their flame retardant properties on polymeric systems. However, a limited number of studies shed light on the mechanism of flame retardancy of their combination on cotton fabrics. The purpose of this research is to gain an understanding of the thermal degradation process of two triazine-phosphonate derivatives on cotton fabric. The investigation included the preparation of diethyl 4,6-dichloro-1,3,5-triazin-2-ylphosphonate (TPN1) and dimethyl (4,6-dichloro-1,3,5-triazin-2-yloxy) methyl phosphonate (TPN3), their application on fabric materials, and the studies of their thermal degradation mechanism. The studies examined chemical components in both solid and gas phases by using attenuated total reflection infrared (ATR-IR) spectroscopy, thermogravimetric analysis coupled with Fourier transform infrared (TGA-FTIR) spectroscopy, and 31P solid state nuclear magnetic resonance (31P solid state NMR), in addition to the computational studies of bond dissociation energy (BDE). Despite a few differences in their decomposition, TPN1 and TPN3 produce one common major product that is believed to help reduce the flammability of the fabric. [ABSTRACT FROM AUTHOR]