scholarly journals Biocide Activity of TiO2 Nanostructured Films

2010 ◽  
Vol 9 ◽  
pp. 17-24 ◽  
Author(s):  
Edgar Barajas-Ledesma ◽  
M.L. García-Benjume ◽  
I. Espitia-Cabrera ◽  
A. Bravo-Patiño ◽  
M.E. Contreras-García

The ability of nanostructured TiO2 in anatase phase to eliminate Escherichia coli (E. coli) by UV light irradiation was tested using titania films supported on glass substrates. The films were obtained by electrophoretic deposition of titania sol on sputtered Ti Corning glass substrates. Experimental procedure used to obtain these films and their characterizations are discussed in this paper. Nanostructure nature of the films was analyzed using scanning electron microscopy and atomic force microscopy. Optic microscopy was used to study the photocatalytic activity of films and their interaction with E. coli bacteria, in order to measure the reduction in E. coli colonies. The structure of anatase TiO2 was determined using grazing incidence X-ray diffraction.

2011 ◽  
Vol 493-494 ◽  
pp. 473-476
Author(s):  
E.O. Lopez ◽  
F.F. Borghi ◽  
Alexandre Mello ◽  
J. Gomes ◽  
Antonella M. Rossi

In this present work, we characterize HAp thin films deposited by dual magnetron sputtering device DMS on silicon (Si/HAp). The sputtering RF power was varied from 90 watts to 120 watts and deposition times from 60 to 180 minutes. The argon and oxygen pressure were fixed at 5.0 mTorr and 1.0 mTorr, respectively. Grazing incidence X-ray diffraction (GIXRD) from synchrotron radiation, infrared spectroscopy (FTIR) and atomic force microscopy (AFM) were used for the structural characterization. At lower deposition times, a crystalline phase with preferential orientation along apatite (002) and a disordered nanocrystalline phase were identified. The coating crystallinity was improved with the increase of the deposition time besides the sputtering power.


2013 ◽  
Vol 770 ◽  
pp. 177-180 ◽  
Author(s):  
Nirun Witit-Anun ◽  
Jakrapong Kaewkhao ◽  
Surasing Chaiyakun

Aluminum nitride (AlN) thin films have been deposited on the glass slide and Si-wafer by reactive DC magnetron sputtering technique at different sputtering power. The as-deposited films have been characterized by grazing-incidence X-ray diffraction (GIXRD), atomic force microscopy (AFM) and optical transmittance, respectively. The results show that the as-deposited films were transparent and have high transmittance in visible regions. The crystal structure from XRD results show that the as-deposited films are amorphous with low sputtering power and turn to crystal structure with high sputtering power, which showed orientation of AlN structure corresponding to the AlN(1 0 0), AlN(1 0 1) and AlN(1 1 0). The roughness values and the films thickness from AFM was varied from 0.4 nm to 3.9 nm and 199 nm to 905 nm, respectively. The optical constants namely the refractive index n and the extinction coefficient k, were determined from transmittance spectrum in the visible regions by using envelope method. For 500 nm, n and k, were in the range of 1.8 2.0 and 0.014 0.004 respectively.


2015 ◽  
Vol 245 ◽  
pp. 42-48 ◽  
Author(s):  
Dmitrii Vladimirovich Fomin ◽  
Victor Leonidovich Dubov ◽  
Konstantin Nickolaevich Galkin ◽  
Dmitrii L'vovich Goroshko ◽  
Andrei Mikhailovich Maslov ◽  
...  

BaSi2 thin films were formed on Si (111) substrate by solid-phase epitaxy (SPE) (UHV deposition) using the template technology followed by vacuum annealing at temperatures of 600 °C and 750 °C. After the deposition and annealing barium silicide films were characterized by Auger electron spectroscopy, grazing incidence x-ray diffraction (GIXRD) and atomic-force microscopy (AFM). It was established that the films annealed at T = 600 °C are polycrystalline with the structure of the orthorhombic BaSi2, with grain sizes of 100-200 nm. Higher anneal temperature (T=750 °C) leads to increase of diffraction peak intensity of BaSi2 phase with grain coagulation into 300-400 nm islands. It was confirmed that nanocrystalline BaSi2 films are characterized by a direct fundamental interband transition at 1.3 eV, the second interband transition with an energy of 2.0 eV, own phonon structure with wave number peaks at 112, 119, 146 and 208 cm-1 and a high density of defect states within the band gap, which provide a noticeable subband absorption at energies of 0.8 – 1.1 eV.


Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1059
Author(s):  
Patricia Capellato ◽  
Daniela Sachs ◽  
Lucas V. B. Vasconcelos ◽  
Miriam M. Melo ◽  
Gilbert Silva ◽  
...  

The current metallic biomaterial still presents failures associated with the bulk alloy and the interface of material/human body. In previous studies, titanium alloy with tantalum showed the elastic modulus decrease in comparison with that of commercially pure (cp) titanium. In this study, surface modification on Ti-30Ta alloy was investigated. Titanium and tantalum were melted, homogenized, cold-worked by a rotary swaging process and solubilized. The anodization process was performed in electrolyte contained glycerol + NH4F 0.25% at 30 V using seven different durations—4 h, 5 h, 6 h, 7 h, 8 h, 9 h, and 10 h and annealed at 530 °C for 1 h. The surface topography was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) measurements, X-ray diffraction analysis (XRD), and contact angle. From the results, we conclude the time of anodization process influences the shape and morphology of the anodized layer. The 5 h-anodization process produced a smooth and porous surface. The 4-, 6-, 7-, 8-, 9-, and 10-h conditions showed nanotubes morphology. All surfaces are hydrophilic (<90°). Likewise, all the investigated conditions present anatase phase. So, this surface modification presents potential for biomedical application. However, more work needs to be done to better understand the influence of time on the anodization process.


2013 ◽  
Vol 594-595 ◽  
pp. 1131-1135 ◽  
Author(s):  
Fariza Mohamad ◽  
Connie Anak Abang ◽  
Nik Hisyamudin Muhd Nor ◽  
Masanobu Izaki

Zinc Oxide (ZnO) has been successfully electrodeposited on a fluorine doped tin oxide (FTO) coated glass substrates using a simple aqueous solution containing zinc nitrate hydrate by low temperature galvanostatic electrolysis. The solution temperature of zinc nitrate hydrate was varied from 60°C to 75°C in order to investigate the effect of solution temperature on electrodeposit-ZnO thin film. The properties of ZnO film were investigated by X-ray diffraction (XRD), Field-Emission Scanning electron microscope (FE-SEM) and Atomic force microscopy (AFM). The solution temperature shows a significant effect on structural and morphological of deposit-ZnO. The XRD patterns exhibited the increment of (002)-ZnO peak when the solution temperature increased and the highest peak was observed at 75°C. The morphology of ZnO was changed from planar to nanopillar with the solution temperature. In conclusion, ZnO nanopillar with an excellent structural properties was obtained at solution temperature of 75°C.


2008 ◽  
Vol 8 (8) ◽  
pp. 4231-4237 ◽  
Author(s):  
Madhavi Thakurdesai ◽  
T. Mohanty ◽  
J. John ◽  
T. K. Gundu Rao ◽  
Pratap Raychaudhuri ◽  
...  

Nanodimensional TiO2 has wide application in the field of photocatalysis, photovoltaic and photochromic devices. In present investigation TiO2 thin films deposited by pulsed laser deposition method are irradiated by 100 MeV Ag ion beam to achieve growth of nanophases. The nanostructure evolution is characterized by atomic force microscopy (AFM). The phases of TiO2 formed after irradiation are identified by glancing angle X-ray diffraction and Raman spectroscopy. The particle radius estimated by AFM varies from 10–13 nm. Anatase phase of TiO2 is formed after irradiation. The blue shift observed in UV-VIS absorption spectra indicates the nanostructure formation. The shape and size of nanoparticles formed due to high electronic excitation depend upon thickness of the film.


2009 ◽  
Vol 60-61 ◽  
pp. 11-15 ◽  
Author(s):  
Pe Min Lu ◽  
Hong Jie Jia ◽  
Shu Ying Cheng

SnS and Ag films were deposited on glass substrates by vacuum thermal evaporation successively, then they were annealed in N2 ambience at a temperature of 300 oC for 2h. By controlling the Ag evaporation voltage to roughly alter content of Ag in SnS films, different Ag-doped SnS films were obtained. The microstructures, composition and properties of the films were characterized with X-ray diffraction ( XRD ), atomic force microscopy(AFM) and some other methods. With the increase of Ag evaporation voltage (VAg), there exist new phases of Ag8SnS6 and Ag2S, whose intensity of diffraction peaks increases with the increasing Ag-dopant, and the average roughness of the films varies from 18.7nm to 23.6nm, and grain size increases from 192nm to 348nm. With the increase of VAg, the evaluated direct band gap Eg of the films decreases from 2.28eV(undoped) to 2.05eV (VAg=70V), the carrier concentration value and Hall mobility of the films diminishes from 2.048×1014cm-3 and 25.96 cm2.v-2.s-1 to 1.035×1016 cm-3 and 5.66 cm2.v-2.s-1, respectively; while the resistivity of the films decreases sharply from 1174Ω.cm(undoped ) to 107Ω.cm (VAg=70V ). All the films are of p-type conductivity. The above results show that the semiconducting properties of the SnS films have been improved by silver-doping.


2018 ◽  
Vol 25 (1) ◽  
pp. 40-50
Author(s):  
Basma Abbas Abdulmajeed ◽  
Sameera Hamadullah ◽  
Fadhil Abed Allawi

Ethanol as a solvent, a precursor of titanium isopropoxide and a stabilizer of either hydrochloric acid or ammonium hydroxide was used to prepare a titanium dioxide aqueous solution. The aqueous solutions with different values of pH and the morphology of the resultant reaction of the nanoparticles of titanium dioxide were investigated. The X-ray diffraction showed that at low temperatures and with acidic solutions, rutile structures are more favorable to grow on titanium dioxide synthesized, while at low and average temperatures and with base solutions, anatase phase is more pronounced. The crystalline form and the re-confirmation of the crystallite size growth were observed by the scanning electron microscopy. The atomic force microscopy was used to confirm the relation between the roughness and thickness with the pH level.  


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