TiO2-SiO2/chitosan nanocomposite was synthesized using simple sonochemical technique. The characteristics of the synthesized nanocomposite were examined by TEM, SEM and EDX analysis. The performance of the prepared TiO2-SiO2/chitosan nanocomposite as efficient sonocatalyst was investigated for the degradation of methyl red. Sonocatalytic degradation of methyl red in the presence of TiO2-SiO2/chitosan nanocomposite could be described via the mechanisms of hot spots and sonoluminescence. The optimized values for main operational parameters were detected as pH of 3, TiO2-SiO2/chitosan dosage of 450 mg/L, methyl red initial concentration of 20 mg/L and ultrasonic power of 300 W. Under optimal conditions, the sonocatalytic degradation of methyl red was 99.1 %. Based on the obtained results, TiO2-SiO2/chitosan nanocomposite could be an excellent selectivity for sonocatalytic degradation of anionic dyes such as methyl red.

Background: The purpose of this work was to investigate the use of polyvinyl chloride (PVC) dyed with methyl red as a high dose radiation dosimetry. Materials and Methods: Commercial PVC films from Sabic made from resins PVC57S with thickness of 60 mm and methyl red with a molecular weight of 269.31 were used. Irradiation was carried out using a60Co g-ray generator with sources arranged in rectangular holder with a total activity of 73.6926 kCi. Absorbance measurements were made by Jasco V- 630 UV-VIS spectrophotometer. Dose rate and irradiation temperature effects as well as post-irradiation storage in dark and indirect daylight conditions on dosimetry performance were also investigated.Results: The results showed a linear relationship between the relative absorbance (response) and the absorbed dose at the wavelength 548 nm in the range of 0-150 kGy. The response was found to be independent of both dose rate and irradiation temperature.Conclusion: The experimental results indicate that PVC films dyed with methyl red may be used for a high dose radiation dosimetry.

In this research, magnetic and photocatalytic nanoparticles of copper ferrite were synthesized using hydrothermal methods. The synthesis was repeated in the presence of ultrasound waves to determine the effect of these waves on the nanostructure of the materials. photocatalytic property of copper ferrite was investigated in the degradation of two toxic dyes, methyl orange and methyl red under UV- IR radiation. Due to magnetic property of copper ferrite nanoparticles, they have the ability to direct photocatalytic reaction products out of the reaction environment too. On the other hand, aluminum hydroxide and aluminum oxide nanoparticles were also synthesized by the same method. Aluminum oxide nanoparticles with high porosity are very suitable absorbents for color absorption. Finally, a core-shell magnetic nanocomposite was made with copper ferrite, alumina and aluminum hydroxide absorbers with hydrothermal method assisted by ultrasound waves and the photocatalytic potential of prepared nanocomposite was assessed using acidic pH methyl orange and methyl red solutions under UV- IR radiation. Also all of products were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometry (VSM).

The photocatalytic degradation of methyl orange and Congo red dye was performed under the illumination of visible light (Philips 250Watt) as a source of photons. The complete distraction of the aromatic ring was ascertained by UV spectroscopic analysis. A decrease in dye concentration and an increase in the concentration of CO2 indicate dye mineralization. The behavior of this reaction was pseudo-first-order and the maximum photodecolorization efficiency was ~85. 16% for Methyl orange and ~ 95. 40 for Congo red in 120-150 min. at 30 o C.