Preparation Of TiO₂ Nanosol And Study Of Its Application In Decelerating UV-Photodegradation Of Aramid Fibers

Aramid is a kind of photosensitive material and it is prone to degrade under ultraviolet radiation. Wavelength of 280～320nm, corresponding to UV radiation, is most sensitive to aramids. Therefore, aramid fibers can be protected from photodegradation and prolonged their longevity of use by addition of proper anti-UV agers capable of inhibiting light within wavelength. A lot of studies have discovered that TiO2 of nano size can provide good protective benefit by reflecting, scattering or absorbing harmful UV rays.In this paper, the TiO2 sol was prepared based on the principle of the sol-gel technology and also was used on textile combined with the strongpoint of the sol-gel process and the feature of the textile. of the textile. The results showed that the textiles treated by the TiO2 sol had the good mufti-functional abilities such as shielding ultraviolet.A lot of studies have discovered that TiO2 of nano size can provide good protective benefit by reflecting, scattering or absorbing harmful UV rays.Some studies of the TiO2 sol in organic solvent were reported in some public journal. For decreasing the quantity of the organic solvent and saving the environment, this paper is focused on the preparation of stable TiO2 sol by using titanium alkoxide as precursor and water as solvent while adding acetic acid for the purpose of moderating the rate of hydrolysis, proper dispersant. To form a proper coating on the surface of aramid fibers, sol-gel, a wet chemical method is used in the present study to make nanoparticles disperse evenly in the coating to sheathe the surface of aramid fibers as an anti-ager.This study includes the preparation of TiO2 nanosol, the characterizations of TiO2 sol and coating prepared by this method, the change of mechanical properties and the surface structure of TiO2 coated aramid fibers under accelerated UV aging treatment.The anti-aging effect of the TiO2 coating is studied by accelerated aging test with a LTV lamp. During the period of aging, the mechanical properties of the coated fibers with TiO2 are studied in comparison with uncoated ones, including tensile strength and extension. The analysis results of SEM and XPS show that the quantity of carboxylic acids as the major products for coated fibers clearly lower than the one for uncoated fibers. It means that the TiO2 coating on aramid fibers can protect amide bonds against photocleavage by means of UV absorption, preventing or decelerating the photodegradation of aramid fibers.The results show that the TiO2 coating decreases the intensity of UV light on aramid fibers resulting in the deceleration of photo degradation of the fibers.