Nano-technology is a super microscopic technology to deal with structures of 100 nm or smaller. This technology also involves the developing of TiO2 materials or TiO2 devices within that size. The aim of the present paper is to synthesize WOx doped nano-TiO2 by the Sonochemistry method and to evaluate the effect of different percentages (0.5-5 wt%) of tungsten oxide load on TiO2 in methylene blue (MB) elimination. The samples were characterized using such different techniques as X-ray diffraction (XRD), TEM, SEM, and UV-VIS absorption spectra. The photo-catalytic activity of tungsten oxide doped TiO2 was evaluated through the elimination of methylene blue using UV-irradiation (315-400nm). The best result was found with 5 wt% WOx doped TiO2. It has been confirmed that WOx-TiO2 could be excited by visible light (E<3.2 eV) and that the recombination rate of electrons/holes in WOx-TiO2 declined due to the existence of WOx doped in TiO2.

In chemistry, the study of sonochemistry is concerned with understanding the effect of sonic waves and wave properties on chemical systems. In the area of chemical kinetics, it has been observed that ultrasound can greatly enhance chemical reactivity in a number of systems by as much as a million-fold. Nano-technology is a super microscopic technology in which structures of 100 nanometers or smaller can be investigated. This technology has been used to develop TiO2 materials and TiO2 devices of that size. Thus far, electrochemistry methods and photochemistry methods have generally been used to create TiO2 nano-size particles. However, these methods are complicated and create pollutants as a by-product. In the present study, nano-scale silver particles (5 nm) were prepared in a sonochemistry method. Sonochemistry deals with mechanical energy that is provided by the collapse of cavitation bubbles that form in solutions during exposure to ultrasound. TiO2 powders 25 nm in size doped with Ag were formed using an ultrasonic sound technique. The experimental results showed the high possibility of removing pollution through the action of a photocatalyst. This powder synthesis technique can be considered as an environmentally friendly powder-forming processing owing to its energy saving characteristics.

Si3N4에 2wt% Al2O3와 6wt% Y2O3을 첨가한 분말을 가스압 소결 방법으로 시편을 제조하였다. 이때 소결시 시간변화에 따른 공기 중에서 마모 특성을 비교하였다. 소결 시간에 따른 마모 특성의 변화는 기계적 성질, 즉, 파괴인성 등이 영향을 주는 것으로 나타났다. 소결 시간이 길어지면 큰 elongated 입자의 과잉성장에 따라 곡강도 및 파괴인성이 낮아져 이 결과 마모가 증가되었다. 이때 나타난 결과에 의하면 공기 중에서 질화규소의 마모특성에 영향을 주는 인자는 여러 가지 기계적 특성 중에서 파괴인성 및 곡강도가 미치는 영향이 크게 나타났다.