Fabrication of Visible Light-Induced Antibacterial and Self-Cleaning Cotton Fabrics Using Manganese Doped TiO₂ Nanoparticles

Abstract

Ordinary textiles are very often malodorous and the origin of cross-infection. Their microclimate, consisting of moisture, contaminants, and sweat, provides favorable conditions for microbial growth. Therefore, simple approaches of surface modification using functional materials are widely adopted to introduce antibacterial properties. This study reports a simple and low cost technique that renders cotton fabrics antibacterial. Manganese (Mn)-doped photocatalytic titanium dioxide (TiO2) nanoparticles of ∼150 nm average diameter have been prepared by sol gel and applied on textile fabrics using a silicone binder. The treated fabrics displayed 100% reduction of Staphylococcus aureus (Gram-positive) and Klebsiella pneumoniae (Gram-negative) populations within 120 min under sunlight, demonstrating first order of reduction kinetics. Moreover, the functionalized fabrics demonstrated complete degradation of a methylene blue (MB) dye adsorbed on their surface, under both UV and visible light irradiation, turning them white. A similar effect was observed when the treated fabrics were immersed in a MB dye solution and subsequently irradiated. Here, the cotton fabrics functionalized with Mn-doped TiO2 nanoparticles were able to discolour the dissolved MB dye, demonstrating a water purification effect. In addition, the modified fabrics were resistant to several laundry cycles. Physical properties like mechanical strength, color, breathability, and aesthetic of the treated cotton fabrics remained unchanged. The modified cotton fabrics can be envisioned as antibacterial, antiodorous, and self-cleaning textiles for sports, medical uses, uniforms, fashion, home furnishing, and leisure activities. Finally, the treated textiles were found to be biocompatible.

Titanium Dioxide: From Engineering to Applications

“…Mizushima et al determined impurity levels of 1.9 to 3.0 eV below CBM by TiO 2 doping can be doped with a variety of metal ions, including transition metal and rare earth metal ions. For transition metal dopants, such as Fe, Mn, V, Cu, and Cr, both delocalized and localized impurity states will be created within the band gap of TiO 2 along the crystal field splitting of metal 3d orbitals [28][29][30]. Mizushima et al determined impurity levels of 1.9 to 3.0 eV below CBM by doping V, Cr, Mn, and Fe based on a large number of experimental results, and they suggested that cation vacancies may lead to these impurity states [31].…”

Visible-Light Active Titanium Dioxide Nanomaterials with Bactericidal Properties

“…Very recently, Zahid et al prepared Mn-doped TiO 2 NPs (150 nm) by the sol-gel method, and then applied the spray coating technique to apply Mn-doped TiO 2 NPs on cotton fabrics. NPs0, NPs10, NPs25 and NPs50 were designated to the cotton fabrics with zero, 10, 25 and 50 wt% Mn-doped TiO 2 NPs, respectively [298]. The fabrics with and without Mn-doped TiO 2 NPs in the dark exhibited no bactericidal effect because no photocatalytic excitation occurred in the absence of light.…”

“…However, it still requires substantial time and Finally, antibacterial and self-cleaning fabrics have received considerable attention in hospitals and clinics due to the increased risk of healthcare-associated infections. Those fabrics are particularly useful against nosocomial bacteria to protect patients from harmful microorganisms [298,345]. The fabrics made from cotton/Mn-doped TiO 2 NPs have been reported to exhibit full inactivation of S. aureus and K. pneumoniae within 120 min under sunlight (Figure 32a,b) [298].…”

“…Those fabrics are particularly useful against nosocomial bacteria to protect patients from harmful microorganisms [298,345]. The fabrics made from cotton/Mn-doped TiO 2 NPs have been reported to exhibit full inactivation of S. aureus and K. pneumoniae within 120 min under sunlight (Figure 32a,b) [298]. However, one can see that such fabrics need at least 25 wt% Mn-doped TiO 2 NPs for achieving antibacterial properties.…”

Functional Fibers, Composites and Textiles Utilizing Photothermal and Joule Heating

“…Therefore, special functions including antimicrobial [36][37][38][39], warming or cooling [40][41][42], waterproof [43][44][45], or windproof properties [46,47] need to be incorporated into the fibers. As a representative technology, photocatalytic nanomaterials such as titanium dioxide nanoparticles have been combined with fibers to degrade odor-causing chemicals and microbial species under light irradiation to remove any unhealthy odor or bacteria [48][49][50]. In addition, textiles that have not been wet by rain or snow but can transport sweat across clothes, have been fabricated by laminating, coating, or densely packing fibers to provide micropores or hydrophilicity, thereby providing waterproof and windproof properties and maintaining body temperature by controlling the transport of heat, water, and moisture [40][41][42][43][44][45][46][47].…”