PHOTOACTIVE POLYACRYLONITRILE FIBERS COATED BY NANO-SIZED TITANIUM DIOXIDE: SYNTHESIS, CHARACTERIZATION, THERMAL INVESTIGATION

Abstract

Anatase nanocrystals were successfully synthesized and deposited onto polyacrylonitrile fibers with photocatalytic self-cleaning activity using the sol-gel process at low temperature. The original and treated samples have been characterized by several techniques such as scanning electron microscopy, fourier transform infrared spectroscopy, x-ray diffraction, diffuse reflectance spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The TiO 2 nanoparticles, have been found to form a homogeneous thin film on the fiber surface. The photocatalytic activity, tested by measuring the degradation of adsorbed Eosin Yellowish dye. The photoactivity of the titanium dioxide coated fibres is much higher than that observed in case of untreated fibers. The photocatalytic selfcleaning properties of the treated fibers was fully maintained performing several cycles of photodegradation. This preparation technique can be also applied to new fabrics to create self-cleaning properties in them. The thermogravimetric study of PAN/TiO 2 composite showed a slight increase of weight loss in the second step, which implied that, the dehydrogenation and oxygen uptake reactions would be promoted by the TiO 2 to some extent.