Abstract:
The increase of public concern regarding hygienic living environments has accelerated research on anti-microbial modifications for many commodity and technical textile products. This study attempted to produce a durable self-cleaning and antibacterial textile material with a relatively low production cost using inorganic photocatalytic nanoparticles embedded in the textile fibers. Segmented pie bi-component fibers have been attracting a lot of attention across the innumerable textile applications owning to their advanced multifunctional properties. The advantages of the split segmented pie bi-component fibers are that they can be spun and processed as larger fibers, then split into ultra-fine pie shape fibers at conventional melt spinning process rates.
The spinning of segmented pie bi-component fibers was conducted using a combination of polypropylene, polyethylene, and nylon 6 as base materials embedded with 1% TiO [subscript2] in both components. This was conducted using a lab scale two-extruders system. The fibers were prepared by varying winding speeds from free-fall, 300 m/min., 500 m/min., and 700 m/min. The produced fibers were examined for their appearances and surface characteristics using an optical microscope, Scanning Electron Microscope (SEM), and Atomic Force Microscope (AFM). The Differential Scanning Calorimeter (DSC) was used for studying their thermal characteristics. The antibacterial effects of the fibers were assessed using a modified method based on the standard method, AATCC100: Assessment of Antibacterial Finishes on Textile Materials, by adding a visible light source above the test samples. The filament samples were tested with the two test organisms of Staphylococcus aureus and Klebsiella pneumoniae. The numbers of bacteria present were determined, and the percent reduction for the specimens with fibers embedded with TiO[subscript2] and that with fibers without TiO[subscript2] were calculated.
The extruded round fibers were split into irregular minuscule pie-shaped filaments, which significantly increased their photocatalytic surface areas. When the winding mechanism applied to the fibers, the average deniers were decreased by approximately 4.5k%. The calculation of the surface areas of the fibers indicates that the surface area of a 16-pie-shape-segments of a split filament are signigicantly higher than a round intact filament, by approximately 610.0%. The presence of Ti on the detected surface of the split fiber is much higher than that on the intact fiber. The atomic and weight percentages of the Ti on the split fiber surface were increased by 92% and 86% respectively. The percentage of the Gram-positive bacteria reduction (Staphylococcus aureus) and the Gram-negative bacteria reduction (Klebsiella pneumoniae) in the sample with TiO[subscript2] were 80.00% and 42.94% respectively, compared to 0% in the sample without TiO [subscript2].