Fabrication of photochromic,hydrophobic, antibacterial,and ultraviolet-blocking cotton fabric using silica nanoparticles functionalized with a photochromic dye

The aim of this work was the fabrication of cotton fabric with multifunctional properties such as photochromic, hydrophobicity, antibacterial, and ultraviolet (UV) blocking. In this regard, a mixture of silica nanoparticles with spirooxazine as a photochromic dye first applied on the cotton fabric, and then, the fabric surface was coated with an alkylsilane compound. The homogenous distribution of silica and silica/spirooxazine hybrid on the cotton fibers was established by field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray mapping. X-ray diffraction patterns confirmed the amorphous nature of the hybrid on the treated cotton fabric. The photochromic effect of the fabrics was measured after 5-min sunlight irradiation. Other characteristics of treated fabrics, such as antibacterial activity, hydrophobic properties, and UV-blocking activity, were also assessed. The results indicated that adding silica nanoparticles to spirooxazine had a tangible effect on photochromic activity of treated cotton fabrics and its photochromic performance was higher than that of the photochromic dye. The fabric showed stable hydrophobicity with static water contact angle values of 141.2° ± 1°. Moreover, the coated cotton fabric demonstrated proper antibacterial properties and UV-blocking activity.