Abstract
Stannic oxide (SnO2) is widely applied for the detection of various types of gases with high sensitivity and fast response. It has also been widely used in the LCD industry as the transparent electric conductor coating. Iron oxide (Fe2O3) is conventionally adopted in the manufacturing of opto-electronic devices, pigments and electric transformers. Synthesis of nano-SnO2 and some other oxides were reported elsewhere with serious aggregation problems. If agglomeration of the synthesized nano-particles could not been avoided, it is meaningless for any nano-oxide forming process no matter how small the particle size could be reached initially.Objective of the studies has been focused on the synthesis of uniform nano-oxides via a microwave irradiation process. Stannic chloride and iron chloride were selected as the starting materials for the synthesis of nano-SnO2 and Fe2O3, respectively. Urea was used as the in-situ pH adjustor in the process. The main procedures for forming nano-oxides include: i) dissolution of metal chlorides in water, ii) formation of micelle by introducing polymeric surfactants such as polyvinyl alcohol (PVA) and Polyvinyl pyrrolidone (PVP), and iii) microwave irradiation of the reactants stabilized in the micelles and formation of nano-oxides without agglomeration. Experimental results show that uniform nano-SnO2 can be prepared by the microwave-micelle process with particle size down to 10 nm.The experimental results were characterized by high resolution transmission electron microscopy (HRTEM), scanning electronic microscopy (SEM), X-Ray diffractometer (XRD), Fourier transformed infred spectroscopy (FTIR), nuclear magnetic resonance analyzer (NMR), thermal gravimetric analyzer (TGA) and differential thermal analyzer (DTA).