Surface Modification of Polyester by Nano Titanium Dioxide in Alkaline Media and Their Synergism Effect on the Fabric

The effect of alkaline hydrolysis with sodium hydroxide on nano titanium dioxide (nano TiO2) adsorption was studied on polyester fabric surface as well as the influence of nano TiO2 on the alkaline hydrolysis of polyester. To do this, the polyester fabrics were treated with different concentrations of nano TiO2 and boiling sodium hydroxide solution for 1 h. The results revealed that alkaline hydrolysis reduced the weight of the fabric, which was more prominent in presence of nano TiO2. Field emission scanning electronic microscope and energy dispersive X-ray confirmed the presence of nano TiO2 on the polyester fabric surface. Increasing sodium hydroxide and nanoTiO2 concentrations led to higher loading of nano particles on the polyester fabric surface. Also, the photocatalytic activity of nano TiO2 particles on the polyester fabric was confirmed by the degradation of methylene blue as a model stain under daylight irradiation. The results indicated that increasing sodium hydroxide and nano TiO2 concentrations led to higher photocatalytic activities of the alkali-treated polyester fabrics. Further, the bending rigidity of the treated polyester fabrics decreased while the water absorption of the fabric improved. Unexpectedly, the tensile strength of the nano TiO2 treated polyester fabrics improved even with the action of alkali and surface hydrolysis that usually produce fabric with lower tensile strength. The synergism influence of nano TiO2 particles in alkali hydrolysis of polyester fabric indicated to lower weight fabrics. Overall, this treatment was considered as another useful property such as higher self-cleaning, hydrophilicity and tensile strength

Development of electrodeposited multilayer coatings: A review of fabrication, microstructure, properties and applications

The demand for robust engineering materials demonstrating good tribological performance under arduous service conditions has forged the development of novel coating materials and techniques. In the field of surface engineering, multilayer structures have attracted great interest. Electrodeposition offers a versatile and controlled route to engineering coatings in tribology. Electrodeposited coatings can provide tailored electronic, magnetic, mechanical, wear-resistant and corrosion-resistant characteristics as well as an improved load-bearing capability. The performance of multilayered electrodeposits can significantly exceed that of single layers. This paper critically reviews the fabrication, microstructure, engineering properties and potential applications of electrodeposited multilayer coatings. Such coatings can provide powerful, complementary additions to the toolkit for engineering electrodeposition, enabling future advances. Critical aspects requiring further R & D endeavors are identified