W Gao

By Yuxin Wang and Wei Gao

Nano-composite coatings have wide applications for their superior mechanical and corrosion properties. Many efforts have been devoted to the development of different types of nano-composite coatings in the last decade. Various techniques are used to modify the coating microstructure at the nano scale in order to further improve the properties of coatings. We recently developed a novel method which combines sol-gel process and electrochemical deposition process to produce nano-composite coatings. This simple method can lead to a highly dispersed distribution of oxide nano-particles in the metal coating matrix, resulting in significantly improved mechanical properties. This Chapter introduces the principle of this innovative method, the basic theory behind the deposition process, and an overview of current results. It also describes the dopant technology that is derived from this novel technique. The future development potentials and industrial applications of these coatings are also discussed.

Part of the book: Electrodeposition of Composite Materials

By Dessy Ariyanti, Dina Lesdantina, Ariana Aisa, Farida Diyah Hapsari, Filicia Wicaksana and Wei Gao

Like many other textile industries, batik requires a lot of water, and its use of different dyes and other chemicals accounts for most of the water pollution (17–20%). It can reduce light penetration, which in turn may decrease photosynthetic activity, and it may also have an impact on the quantity of oxygen available for the biodegradation of aquatic microbes. Many dyes, including diazo (-N〓N-), direct, and basic dyes, are challenging to work with using standard techniques, and the byproducts may occasionally be quite hazardous. Photocatalysis with various semiconductor materials has been the focus of investigations in recent years for the wastewater treatment application. Among many semiconductors, because of its strong photocatalytic activity, outstanding stability, lack of toxicity, and affordability, TiO₂ is still the most extensively used photocatalyst. When a catalyst (TiO₂) is exposed to ultraviolet (UV) light, hydroxyl radicals (•OH) are produced in the UV/TiO₂ photocatalytic oxidation process. Organic materials therefore mineralize into CO₂, H₂O, and inorganic components. In this chapter the application of continuous tubular photoreactor with TiO₂ nanoparticles as a catalyst for Batik wastewater treatment is reviewed.

Part of the book: Wastewater Treatment - Past and Future Perspectives [Working title]