Loading...
Search for:
titanium-dioxide
0.009 seconds
Total 507 records
In situ growth of vanadia-titania nano/micro-porous layers with enhanced photocatalytic performance by micro-arc oxidation
, Article Electrochimica Acta ; Volume 55, Issue 9 , 2010 , Pages 3093-3102 ; 00134686 (ISSN) ; Moshfegh, A. Z ; Golestani Fard, F ; Sharif University of Technology
2010
Abstract
Micro-arc oxidation process was used to synthesize V2O5-TiO2 porous layers for the first time. Surface morphology and topography of the layers were investigated by scanning electron microscope (SEM) and atomic force microscope (AFM). X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques were also employed to evaluate phase structure and chemical composition of the layers. It was found that the V2O5-TiO2 layers consisted of anatase, rutile, and vanadium pentoxide phases fraction of which varied with the applied voltage and the electrolyte concentration. It was also revealed that pore size and surface roughness increased with the applied voltage and the electrolyte...
Low temperature nanostructured zinc titanate by an aqueous particulate sol-gel route: Optimisation of heat treatment condition based on Zn:Ti molar ratio
, Article Journal of the European Ceramic Society ; Volume 30, Issue 4 , 2010 , Pages 947-961 ; 09552219 (ISSN) ; Fray, D. J ; Sharif University of Technology
2010
Abstract
Nanocrystalline zinc titanate (ZnTiO3) thin films and powders with purity of 94% were produced at the low sintering temperature of 500 °C and the short sintering time of 1 h by a straightforward aqueous particulate sol-gel route. The effect of Zn:Ti molar ratio was studied on the crystallisation behaviour of zinc titanates. The prepared sols showed a narrow particle size distribution in the range 17-19 nm. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) revealed that the powders contained mixtures of the rhombohedral-ZnTiO3, cubic-ZnO, cubic-Zn2TiO4 phases, as well as the anatase-TiO2 and the rutile-TiO2 depending on the sintering temperature and Zn:Ti molar ratio....
Synthesis of narrow band gap (V2O5)x-(TiO2)1-x nano-structured layers via micro arc oxidation
, Article Applied Surface Science ; Volume 256, Issue 9 , 2010 , Pages 2903-2909 ; 01694332 (ISSN) ; Moshfegh, A. Z ; Golestani Fard, F ; Sharif University of Technology
Abstract
V2O5-TiO2 layers with a sheet-like morphology were synthesized by micro arc oxidation process for the first time. Surface morphology and topography of the layers were investigated by scanning electron microscope (SEM) and atomic force microscope (AFM). Phase structure and chemical composition of the layers were also studied by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. It was revealed that the composite layers had a sheet-like structure average thickness of which was about 100 nm depending on the applied voltage. The layers consisted of anatase, rutile, and vanadium pentoxide phases fractions of which varied with the applied voltage. The optical properties...
Doxorubicin hydrochloride - loaded electrospun chitosan/cobalt ferrite/titanium oxide nanofibers for hyperthermic tumor cell treatment and controlled drug release
, Article International Journal of Biological Macromolecules ; Volume 116 , 2018 , Pages 378-384 ; 01418130 (ISSN) ; Bahmani, E ; Sarikhani, E ; Rahmani, K ; Sharifianjazi, F ; Irani, M ; Sharif University of Technology
Abstract
In the present study, the potential of doxorubicin hydrochloride (DOX)-loaded electrospun chitosan/cobalt ferrite/titanium oxide nanofibers was studied to investigate the simultaneous effect of hyperthermia and chemotherapy against melanoma cancer B16F10 cell lines. The cobalt ferrite nanoparticles were synthesized via microwave heating method. The titanium oxide nanoparticles were mixed with cobalt ferrite to control the temperature rise. The synthesized nanoparticles and nanofibers were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and vibrating sample magnetometer (VSM) analysis. The DOX loading efficiency and in vitro drug release of...
Novel fluoridated silk fibroin/ TiO2 nanocomposite scaffolds for bone tissue engineering
, Article Materials Science and Engineering C ; Volume 82 , 2018 , Pages 265-276 ; 09284931 (ISSN) ; Madaah Hosseini, H. R ; Samadikuchaksaraei, A ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
It is known that Fluoride ions strongly affect bone mineralization and formation. In the present study, the engineered bone tissue scaffolds are fabricated using silk fibroin (SF) and flouridated TiO2 nanoparticles. TiO2 nanoparticles are modified by fluoride ions, and different levels (0, 5, 10, 15 and 20 wt%) of the fluoridated TiO2 nanoparticles (TiO2-F) were subsequently added to the SF matrix through phase separation method to prepare silk fibroin/flouridated TiO2 nanocomposite scaffolds (SF/TiO2-F). Phase structure, functional groups, morphology and mechanical properties of the obtained scaffolds were evaluated by X-ray diffraction method (XRD), Fourier transform infrared spectroscopy...
Fabrication of chitosan/poly(lactic acid)/graphene oxide/TiO2 composite nanofibrous scaffolds for sustained delivery of doxorubicin and treatment of lung cancer
, Article International Journal of Biological Macromolecules ; Volume 110 , 2018 , Pages 416-424 ; 01418130 (ISSN) ; Moradkhani, M ; Beheshti, H ; Irani, M ; Aliabadi, M ; Sharif University of Technology
Elsevier B.V
2018
Abstract
In this work, the synthesized graphene oxide/TiO2/doxorubicin (GO/TiO2/DOX) composites were loaded into the chitosan/poly(lactic acid) (PLA) solutions to fabricate the electrospun chitosan/PLA/GO/TiO2/DOX nanofibrous scaffolds via electrospinning process. The synthesized composites and nanofibers were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. Three-factor three-level central composite design was used to determine the influence of PLA to chitosan ratio, TiO2/DOX content and GO/TiO2/DOX content on the release of DOX from nanofibrous scaffolds. Drug loading efficiency and drug release behavior from...
Kinetics investigation of the photocatalytic degradation of acid blue 92 in aqueous solution using nanocrystalline TiO2 prepared in an ionic liquid
, Article Progress in Reaction Kinetics and Mechanism ; Volume 34, Issue 1 , 2009 , Pages 55-76 ; 14686783 (ISSN) ; Rahimnejad, S ; Rahman Setayesh, S ; Hosseini, M ; Gholami, M. R ; Sharif University of Technology
2009
Abstract
TiO2 nanoparticles were prepared by the sol - gel process using 2-hydroxylethy- lammonium formate as an ionic liquid. Nanoparticles were crystallized at various temperatures (300-700°C). The products were characterized using X-ray diffraction (XRD), nitrogen adsorption - desorption isotherms and scanning electron microscopy (SEM) techniques. It was found that the resulting TiO2 nanoparticles had good thermal stability either to resist collapse or the anatase-to-rutile phase transformation during heat treatment. The photocatalytic activity of the nanocrystalline TiO2 was evaluated by the degradation of Acid Blue 92 (AB92) which is commonly used as a textile dye. The results showed that the...
Low-temperature perovskite-type cadmium titanate thin films derived from a simple particulate sol-gel process
, Article Acta Materialia ; Volume 57, Issue 4 , 2009 , Pages 1049-1059 ; 13596454 (ISSN) ; Fray, D. J ; Sharif University of Technology
2009
Abstract
Low-temperature perovskite-type cadmium titanate (CdTiO3) with a nanocrystalline and mesoporous structure was prepared at various Ti:Cd molar ratios by a straightforward particulate sol-gel route. The prepared sols had a narrow particle size distribution, in the range 23-26 nm. X-ray diffraction and Fourier transform infrared spectroscopy revealed that the powders contained a mixture of ilmenite-CdTiO3, perovskite-CdTiO3, anatase and rutile phases, depending on the annealing temperature and the Ti:Cd molar ratio. Perovskite-CdTiO3 was the major type obtained from cadmium-prominent powders at low temperature, whereas ilmenite-CdTiO3 was the major type obtained from titanium-prominent powders...
Synthesis of cellulose acetate/chitosan/SWCNT/Fe3O4/TiO2 composite nanofibers for the removal of Cr(VI), As(V), Methylene blue and Congo red from aqueous solutions
, Article International Journal of Biological Macromolecules ; Volume 140 , 2019 , Pages 1296-1304 ; 01418130 (ISSN) ; Koushkbaghi, S ; Pishnamazi, M ; Askari, A ; Khosravi, R ; Irani, M ; Sharif University of Technology
Elsevier B.V
2019
Abstract
The potential of electrospun cellulose acetate/chitosan/single walled carbon nanotubes/ferrite/titanium dioxide (CA/chitosan/SWCNT/Fe3O4/TiO2) nanofibers was investigated for the removal of Cr(VI), As(V), Methylene blue and Congo red from aqueous solutions via the adsorption and photocatalytic reduction processes. The properties of synthesized SWCNT/Fe3O4/TiO2 and fibers were characterized using TEM, SEM, FTIR, XRD, TGA and BET analysis. In adsorption process, the influence of adsorbent type including SWCNT to Fe3O4 ratio, TiO2 to SWCNT/Fe3O4 ratio and SWCNT/Fe3O4/TiO2 concentration as well as the adsorption parameters including pH, contact time, and initial concentration of adsorbates on...
Toward higher extraction and enrichment factors via a double-reservoirs microfluidic device as a micro-extractive platform
, Article Journal of Separation Science ; Volume 42, Issue 18 , 2019 , Pages 2985-2992 ; 16159306 (ISSN) ; Baraazandeh, M ; Bagheri, H ; Sharif University of Technology
Wiley-VCH Verlag
2019
Abstract
In this study, firstly, a double-reservoir and switchable prototype of a micro-chip along with the respective holders were fabricated. A cyclic desorption process using microliter volume of organic solvent was adopted to prevent any outdoor contamination. As extractive phases, two identical sheets of electrospun polyamide/polypyrrole/titania nanofibers were synthesized using core–shell electro-spinning technique and utilized for determination of memantine in plasma samples. Field emission scanning electron microscopy images showed a high degree of porosity and homogeneity throughout the sheet structure. Also, energy dispersive X-ray analysis confirmed the presence of titania, while the...
Laser irradiation for controlling size of TiO2-Zeolite nanocomposite in removal of 2,4-dichlorophenoxyacetic acid herbicide
, Article Water Science and Technology ; Volume 80, Issue 5 , 2019 , Pages 864-873 ; 02731223 (ISSN) ; Borghei, S. M ; Moniri, E ; Kimiagar, S ; Panahi, H. A ; Sharif University of Technology
IWA Publishing
2019
Abstract
This study focused on the synthesis of TiO2-Zeolite nanocomposite through a sol-gel approach. The decrease in the size of the nanocomposite is considered a primary parameter to improve photocatalytic activity. In this regard, fabricated samples were exposed to laser irradiation (532 nm) for four different time intervals in order to investigate the size variation of the nanocomposite. FTIR, UV-Vis, XRD, DLS, SEM and EDX analyses were applied to characterize and determine the size of the products. An optimized nanocomposite sample, in term of the particle size, was used for photodegradation of 2,4-D herbicide from aqueous solution. Photodegradation was carried out under UV irradiation (12 W)...
Corrosion resistance and photocatalytic activity evaluation of electrophoretically deposited TiO 2 -rGO nanocomposite on 316L stainless steel substrate
, Article Ceramics International ; Volume 45, Issue 11 , 2019 , Pages 13747-13760 ; 02728842 (ISSN) ; Parvizy, S ; Afshar, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
TiO 2 -rGO nanocomposite coatings were obtained by electrophoretic deposition (EPD) technique of TiO 2 nanoparticles and graphene oxide (GO) on stainless steel substrate. First, GO particles were synthesized using a modified Hummers' method. GO was reduced electrochemically to form a coating in the presence of nano-sized TiO 2 particles. The influences of different parameters such as GO concentration, coupling co-electro-deposition parameters (electrophoretic duration and voltage) on thickness, surface morphology and, corrosion behavior of the as-synthesized TiO 2 -rGO nanocomposite coatings were systematically surveyed. The morphology and microstructure were investigated by field emission...
In vitro study: bond strength, electrochemical and biocompatibility evaluations of TiO2/Al2O3 reinforced hydroxyapatite sol–gel coatings on 316L SS
, Article Surface and Coatings Technology ; 2020 ; Afshar, A ; Sharif University of Technology
Elsevier B.V
2020
Abstract
To improve the biocompatibility and corrosion resistance of 316L SS (Stainless Steel) metal implants, HAp(hydroxyapatite)/TiO2/Al2O3 nanocomposite coating was created using dip sol-gel method sintered at 550 °C. The weight percentage of TiO2+ Al2O3 in these coatings was 20, 30, and 40% wt. In this study, characterization was performed using FTIR (Fourier-Transform Infrared Spectroscopy), XRD, FE-SEM (Field Emission Scanning Electron Microscope), EDS (Energy Dispersive Spectroscopy), DLS (Dynamic Light Scattering), Pull-off, and AFM (Atomic Force Microscopy) analysis. The potentiodynamic polarization and EIS (Electrochemical Impedance Spectroscopy) were performed in the simulated body fluid...
Stimulus-responsive sequential release systems for drug and gene delivery
, Article Nano Today ; Volume 34 , 2020 ; Rabiee, N ; Bagherzadeh, M ; Elmi, F ; Fatahi, Y ; Farjadian, F ; Baheiraei, N ; Nasseri, B ; Rabiee, M ; Tavakoli Dastjerd, N ; Valibeik, A ; Karimi, M ; Hamblin, M. R ; Sharif University of Technology
Elsevier B.V
2020
Abstract
In recent years, a range of studies have been conducted with the aim to design and characterize delivery systems that are able to release multiple therapeutic agents in controlled and programmed temporal sequences, or with spatial resolution inside the body. This sequential release occurs in response to different stimuli, including changes in pH, redox potential, enzyme activity, temperature gradients, light irradiation, and by applying external magnetic and electrical fields. Sequential release (SR)-based delivery systems, are often based on a range of different micro- or nanocarriers and may offer a silver bullet in the battle against various diseases, such as cancer. Their distinctive...
Assembly of CeO 2-TiO 2 nanoparticles prepared in room temperature ionic liquid on graphene nanosheets for photocatalytic degradation of pollutants
, Article Journal of Hazardous Materials ; Volume 199-200 , 2012 , Pages 170-178 ; 03043894 (ISSN) ; Setayesh, S. R ; Habibi Yangjeh, A ; Hormozi Nezhad, M. R ; Gholami, M. R ; Sharif University of Technology
2012
Abstract
CeO 2-TiO 2 nanoparticles were prepared by the sol-gel process using 2-hydroxylethylammonium formate as room-temperature ionic liquid and calcined at different temperatures (500-700°C). CeO 2-TiO 2-graphene nanocomposites were prepared by hydrothermal reaction of graphene oxide with CeO 2-TiO 2 nanoparticles in aqueous solution of ethanol. The photocatalysts were characterized by X-ray diffraction, BET surface area, diffuse reflectance spectroscopy, scanning electron microscopy, and Fourier transformed infrared techniques. The results demonstrate that the room-temperature ionic liquid inhibits the anatase-rutile phase transformation. This effect was promoted by addition of CeO 2 to TiO 2....
Synthesis and characterisation of nanosized TiO2-ZrO2 binary system prepared by an aqueous sol-gel process: Physical and sensing properties
, Article Sensors and Actuators, B: Chemical ; Volume 155, Issue 2 , July , 2011 , Pages 568-576 ; 09254005 (ISSN) ; Fray, D. J ; Sharif University of Technology
2011
Abstract
Nanostructured TiO2-ZrO2 thin films and powders were prepared by a straightforward aqueous particulate sol-gel route. Titanium (IV) isopropoxide and zirconium (IV) acetate hydrate were used as precursors, and hydroxypropyl cellulose was used as a polymeric fugitive agent in order to increase the specific surface area. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy revealed that the powder were crystallised at the low temperature of 500 °C, containing anatase-TiO 2 and tetragonal-ZrO2 phases. Furthermore, it was found that ZrO2 retarded the anatase-to-rutile transformation up to 900 °C. The activation energies for crystallite growth of TiO2 and ZrO2 components in...
The role of TiO2 addition in ZnO nanocrystalline thin films: Variation of photoelectrochemical responsivity
, Article Electrochimica Acta ; Volume 56, Issue 18 , July , 2011 , Pages 6284-6292 ; 00134686 (ISSN) ; Yousefi, M ; Moshfegh, A. Z ; Sharif University of Technology
2011
Abstract
In this study, the effects of TiO2 addition on the physical and photoelectrochemical properties of ZnO thin films have been investigated. The (TiO2)x-(ZnO)1-x nanocomposite thin films were dip-coated on both glass and indium tin oxide (ITO)-coated conducting glass substrates with various values of x, specifically 0, 0.05, 0.1, 0.25 and 0.5. Optical properties of the samples were studied by UV-vis spectrophotometry in the range of 300-1100 nm. The optical spectra of the nanocomposite thin films showed high transparency in the visible region. The optical bandgap energy of the (TiO2)x-(ZnO)1-x films increased slightly with increasing values of x. The crystalline structure of the nanocomposite...
Recent progress in inorganic and composite coatings with bactericidal capability for orthopaedic applications
, Article Nanomedicine: Nanotechnology, Biology, and Medicine ; Volume 7, Issue 1 , Feb , 2011 , Pages 22-39 ; 15499634 (ISSN) ; Tamjid, E ; Pishbin, F ; Boccaccini, A. R ; Sharif University of Technology
Abstract
This review covers the most recent developments of inorganic and organic-inorganic composite coatings for orthopedic implants, providing the interface with living tissue and with potential for drug delivery to combat infections. Conventional systemic delivery of drugs is an inefficient procedure that may cause toxicity and may require a patient's hospitalization for monitoring. Local delivery of antibiotics and other bioactive molecules maximizes their effect where they are required, reduces potential systemic toxicity and increases timeliness and cost efficiency. In addition, local delivery has broad applications in combating infection-related diseases. Polymeric coatings may present some...
Nanostructured TiO2-CeO2 mixed oxides by an aqueous sol-gel process: Effect of Ce:Ti molar ratio on physical and sensing properties
, Article Sensors and Actuators, B: Chemical ; Volume 150, Issue 2 , 2010 , Pages 631-640 ; 09254005 (ISSN) ; Fray, D. J ; Sharif University of Technology
2010
Abstract
Nanostructured TiO2-CeO2 thin films and powders were prepared by a straightforward aqueous particulate sol-gel route. Titanium (IV) isopropoxide and cerium chloride were used as precursors, and hydroxypropyl cellulose was used as a polymeric fugitive agent in order to increase the specific surface area. The effect of Ce:Ti molar ratio was studied on the crystallisation behaviour of the products. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) revealed that the powders crystallised at the low temperature of 500 °C, containing anatase-TiO2, rutile-TiO2 and cubic-CeO2 phases, as well as Ti 8O15, Ti3O5 and Ce 11O20 depending on annealing temperature and Ce:Ti molar...
Transition metal ions effect on the properties and photocatalytic activity of nanocrystalline TiO2 prepared in an ionic liquid
, Article Journal of Hazardous Materials ; Volume 172, Issue 2-3 , 2009 , Pages 1573-1578 ; 03043894 (ISSN) ; Rahimnejad, S ; Setayesh, S. R ; Rohani, S ; Gholami, M. R ; Sharif University of Technology
Abstract
TiO2 and transition metal (Cr, Mn, Fe, Co, Ni, Cu, and Zn) doped TiO2 nanoparticles were synthesized by the sol-gel method using 2-hydroxylethylammonium formate as an ionic liquid. All the prepared samples were calcined at 500 °C and characterized by X-ray diffraction (XRD), BET surface area determination, energy dispersive X-ray (EDX) analysis, diffuse reflectance spectroscopy (DRS), and Fourier transformed infrared (FT-IR) techniques. The studies revealed that transition metal (TM) doped nanoparticles have smaller crystalline size and higher surface area than pure TiO2. Dopant ions in the TiO2 structure caused significant absorption shift into the visible region. The results of...