Search Results (2)

Sunlight is essential for humans. However, sunlight can be the source of several disadvantageous effects and illnesses, e.g., skin aging, sunburn, and skin cancer. Textiles with functional protective effects can counteract these problems. In the current research, knitted fabrics were produced from Lyocell yarns spin-doped with the inorganic UV absorber titanium dioxide TiO₂. Lyocell yarns without TiO₂ were used as reference materials. The produced knitted fabrics were dyed with different dyestuffs to improve the protective properties against UV light and infrared light. The protective properties are determined by optical spectroscopy in an arrangement of diffusive transmission. With the two dyestuffs Drimaren Yellow HF-CD and Solophenyl Bordeaux 3BLE, dyes were determined which complete UV protection and additionally reduce transmission in the near-IR range (700 nm to 1000 nm). TiO₂ in the fibers enhanced this effect. In the UV range (280 nm to 400 nm), the transmission was almost zero with both dyes. Overall, the Lyocell samples containing TiO₂ exhibit less sensitivity to abrasion and a UV protective effect after washing can be still determined. The weight loss after the abrasion test for these samples is quite low with only around 8.5 wt-% (10,000 rubbing cycles in the Martindale device). It is concluded that the right choice of dye can improve the protective effect of textiles against various types of radiation. Lyocell fiber-based textiles are suitable for the production of summer clothing due to their good moisture management. Compared to other radiation protective materials based on coating application, the presented solution is advantageous, because the textile properties of the realized products are still present. For this, a direct transfer to clothing application and use in apparel is easily possible. This study can be seen as the first proof-of-concept for the future development of light-protective clothing products. Full article

This study investigates the potential of a combined photocatalysis–adsorption approach to effectively degrade near wash yellow (NWY), a commonly used and highly persistent dye in the textile industry, notorious for its challenging treatment and removal from wastewater due to its colorfastness. A chitosan–glycerol (CTiG) film combined with titanium dioxide was examined in both batch and continuous-flow experiments under visible solar irradiation. The results show that this combination was more effective than a pure chitosan film (60%) or chitosan–glycerol film (63%), with up to 83% degradation of NWY achieved in just 60 min of visible solar irradiation. The kinetics of the film were evaluated using both pseudo-first-order and Langmuir–Hinshelwood kinetic models. The rate constant values (k, min⁻¹) decreased with increasing NWY concentration from 20 to 80 mg/L, and k was found to be greater than twice as high under visible solar irradiation as it was in the dark. The Langmuir–Hinshelwood model’s K_LH (reaction rate constant) and K_L (adsorption coefficient) values were 0.029 mg/L·min and 0.019 L/mg, respectively. The optimal conditions for NWY degradation were found to be 4% TiO₂ to chitosan ratio, glycerol/chitosan ratio of 40%, and a pH of 7. In the continuous-flow model, the CTiG film was submerged in an 8 L NWY solution (80 mg/L) and degraded at a rate of 22.6 mg NWY/g film under natural sunlight. This study contributes to the development of effective and sustainable methods for the degradation of dyes from textile industry wastewater. Full article