RESUMO
Pure anatase, nanosized and Sn(4+) ion doped titanium dioxide (TiO(2)) particulates (TiO(2)-Sn(4+)) were synthesized by hydrothermal process. TiO(2)-Sn(4+) was used to coat glass surfaces to investigate the photocatalytic antibacterial effect of Sn(4+) doping to TiO(2) against gram negative Escherichia coli (E. coli) and gram positive Staphylococcus aureus (S. aureus). Relationship between solid ratio of TiO(2)-Sn(4+) in coatings and antibacterial activity was reported. The particulates and the films were characterized using particle size analyzer, zeta potential analyzer, Brunauer-Emmett-Teller (BET), X-ray diffractometer (XRD), SEM, AAS and UV/VIS/NIR techniques. The results showed that TiO(2)-Sn(4+) is fully anatase crystalline form and easily dispersed in water. Increasing the solid ratio of TiO(2)-Sn(4+) from 10 to 50% in the coating solution increased antibacterial effect.
Assuntos
Vidro , Estanho/química , Titânio/química , Catálise , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Fotoquímica , Espectrofotometria Ultravioleta , Staphylococcus aureus/efeitos dos fármacosRESUMO
In this study, the thermal catalytic powder mixtures of Mn, Ce and Co oxides supported on Al2O3 were synthesized. In order to obtain thermally active porous coating on the steel substrate, a binder solution produced via sol-gel method was used to bind the synthesized powder. Additionally by incorporation of TiO2 nanoparticles to previously described thermally active coating, both thermally and photocatalytically active multifunctional surfaces were obtained. The self-cleaning property and the rate of volatile organic compounds (VOC) degradation of the coatings were studied, in which pyrazine, thiazole, maltol, vanillin and toluene were applied as VOC. In TiO2 applications UV illuminations were applied. In the self-cleaning performance tests using soybean oil, the thermally active coating was slightly better than the TiO2 containing coatings. Under UV illumination, the high rates of VOC (photo) degradation was achieved with the thermally and photocatalytically active coating.
RESUMO
Pure anatase-TiO2 nanoparticles with 8 nm average crystallite size was synthesized hydrothermally at 200 degrees C in 2 h. The structural and physico-chemical properties of nano-TiO2 were determined by powder XRD, FT-IR, BET and SEM analyses. The behavior of anatase nano-TiO2 in catalytic degradation of Rhodamine B (RB) dye in transparent nano-TiO2 sol under UV-light was examined as a function of irradiation power of UV-light, irradiation time, amount of nano-TiO2 and initial RB concentration in the sol. Rhodamine B was fully degraded with the catalysis of the nano-TiO2 in a short time as low as 60 min. Photocatalytic activity of the nano-TiO2 for degradation of RB was compared with Degussa P-25 at optimum catalysis conditions determined for the nano-TiO2. It was found that, when compared to Degussa P-25, the nano-TiO2 could be repeatedly used with increasing photocatalytic activity. It was found that the photodegradation obeys the pseudo first-order reaction kinetics with the rate constant of 0.0658 min(-1), and the half period t1/2 was 10.53 min.
Assuntos
Rodaminas/química , Titânio/química , Poluentes Químicos da Água , Purificação da Água/métodos , Catálise , Indústria TêxtilRESUMO
In this work, a new filter, used to prevent atmospherical pollution, has been developed. Spherical amorphous shaped silicates (such as KC-Siliperl AF 125 and Aluminium silicate 596 FA) were coated with different materials which were prepared from the hydrolysis-condensation products of organically modified silanes and metal alkoxides. The adsorption capacities of such silicates for different solvents; ethylacetate, toluene, n-hexane and cyclohexanone were investigated. It was found that KC-Siliperl AF 125 coated with IMEO (a commercial silane) adsorbed all the solvents better than Aluminium silicate 596 FA, and ethylacetate was adsorbed more than the other solvents.