Papers by Keyword: Coated

Abstract: The magnetic photocatalyst of CoZnFe₂O₄/SiO₂ nanoparticles has been synthesised to degrade methylene blue (MB) dye. The CoZnFe₂O₄ nanoparticles were prepared by co-precipitation method under mechanical stirring and coated with SiO₂ by stöber method using Na₂SiO₂ with various concentrations of 5%, 10%, 15%, 20%, 30%, and 50%. The properties of CoZnFe₂O₄/SiO₂ was confirmed by x-ray diffraction (XRD), Fourier transforms infrared (FTIR), vibrating sample magnetometer (VSM), and UV-Visible spectroscopy. XRD analysis revealed that CoZnFe₂O₄ had the spinel ferrite phase structure with crystalite size of 17.0 nm, and then after coating with SiO₂, the size became 17.1 nm. FTIR clearly show an M-O octahedral vibrational bond found with a wavelength of 378 cm^-1, O-Si-O, Si-OH, and Si-O-Fe at 1087, 794, and 570 cm^-1, respectively. The saturation magnetization (Ms) and coercivity of CoZnFe₂O₄/SiO₂ was 29.0 emu/g and 251.9 Oe, respectively. Furthermore, the results of UV-Visible data presented that the absorption edges CoZnFe₂O₄/SiO₂ in the range of 190 - 600 nm. The percentage of CoZnFe₂O₄ degradation is 88.4%, while after coted SiO₂ 50%, the degradation becomes 98.9%.

Abstract: Nickle zinc ferrite (NiZnFe₂O₄) magnetic nanoparticle (MNPs) has been successfully synthesized using co-precipitation method. NiZnFe₂O₄ was coated SiO₂ (NiZnFe₂O₄/SiO₂) using Stöber method with various concentrations of (5%, 10%, 15%, 20%, 30%, and 50%). MNPs sample has a spinel ferrite phase confirmed by X-ray diffraction (XRD) measurements. The results of the functional group analysis performed using Fourier transform infrared (FTIR) showed an M-O tetrahedral vibrational bond found a wavelength of 347 cm^-1. After coated silica, Si-O-Si vibrational bonds appear at wavelengths of 1033.85 cm¹. Magnetic properties were measured using vibrating Sample Magnetometer (VSM), the result shows that has maximum saturation magnetization of NiZnFe₂O₄ 22.5 emu.gram^-1 and decreased to 16.9 emu.gram^-1 after coating. In figure 1 show that the photodegradation activity of MNPs was carried out with a variation of irradiation time. Result of the photodegradation activity of methylene blue shows that NiZnFe₂O₄/SiO₂ are higher than NiZnFe₂O₄. Sample of NiZnFe₂O₄/SiO₂ has the highest photodegradation rate up to 96%. The existence of SiO₂ layer on the surface of bare MNPs increases the surface reactivity of samples.

Abstract: In order to improve the conductivity of the nickel fiber, polyaniline (PANI) of synthesis by chemical oxidative polymerization was coated. The influences of dopant type and content, reaction time, reaction temperature and stirring rate on the conductivity of the PANI coated nickel fiber were investigated. SEM and NMR were used to characterize morphology of products. The conductive of the PANI coated nickel fiber was tested by four-point probe conductivity tester. The results showed that the PANI coated layer was uniform and stabilized when the p-toluene sulfonic acid (PTS) used as dopant, the PANI coated nickel fiber has the highest conductivity of 5×10^-5 s∙cm⁻¹when was coated at parameters of the C _(PTS) of 0.1 mol/L, the reaction time of 5 hours, the reaction temperature of 5 °C, as well as the stirring rate of 60 r/min.

Abstract: The water-based gravure ink does not contain volatile organic solvent, which is an environmentally friendly ink. But slow drying is a bottleneck of water-based gravure ink in use. Proposed the water in Water-based gravure ink reacts with temperature control microcapsule drying agent when heated in drying box of gravure printing machine to increase the ink drying speed. Designed preparation purification and drying methodthe of calcium oxide microcapsules, which surface is coated with hydrophobic compound and surfactant. The coating layer of Water-based gravure ink drying agent has good water resistance below 60°C, which will drop from the surface of the calcium oxide in the process of temperature continues to rise. Use the rheometer to test the rheology of water-based gravure ink contain microcapsule drying agent, characterization of the drying effect of the microcapsule drying agent based on the change in viscosity of the ink. Experimental results show that, the excitation temperature of the drying agent is 40°C. The Prepared temperature control microcapsule drying agent can effectively improve the drying speed of the water-based gravure printing ink.