Titanium dioxide nanotubes for production and delivery of nitric oxide and methods for production thereof

The present disclosure describes compositions operable for releasing nitric oxide under photochemical conditions. The compositions include a titanium dioxide nanomaterial and a nitric oxide-releasing compound deposited on the titanium dioxide nanomaterial that is operable to release nitric oxide under photochemical conditions. Titanium dioxide nanomaterials include, for example, titanium dioxide nanotubes. To facilitate the photochemical release of nitric oxide, some embodiments of the compositions further include a semiconductor that is deposited on the titanium dioxide nanotubes. Both the semiconductor and the nitric oxide-releasing compound may be deposited on the interior surface, exterior surface, or both of the titanium dioxide nanotubes. A polymer may wrap the titanium dioxide nanotubes to protect the nitric oxide-releasing compounds from moisture. Also disclosed herein are methods for producing such compositions and medical devices obtained therefrom.Board of Regents, University of Texas Syste

New Design of Potentially Low-cost Solar Cells Using TiO2/Graphite Composite as Photon Absorber

A solar cell design using the combination of titanium dioxide and graphite as active photon absorbing materials were proposed. The titanium dioxide absorbs photons of nearly ultraviolet wavelengths to produce electron hole pairs, while graphite is expected to absorb photons of longer wavelengths. Although many authors have claimed that graphite is not a semiconductor, we observed that a model of a solar cell containing titanium dioxide only as the active material behaves exactly the same as a model containing graphite only as the active material. Additionally, we observed that a model of a solar cell made using a composite of titanium dioxide and graphite as the active material had much higher efficiency than solar cells made using titanium dioxide only or graphite only active materials.Comment: 3 figure

Surface area or diameter – which factor really determines the antibacterial activity of silver nanoparticles grown on TiO₂ coatings?

Titanium dioxide coatings were prepared on Si wafers using the sol–gel method. Four different types of coatings with silver nanoparticles (AgNPs) were synthesized. The diameter and surface density of AgNPs were conditioned by the concentration of Ag+ ions in the initial solution, time and UV illumination source. The bactericidal activity of AgNPs on the titanium dioxide coatings against the S. aureus strain were calculated as the percentage of the inhibition of bacterial growth after 24 hour incubation of microorganisms at 37°C on TiO₂ coatings with AgNPs. Control samples were coated with titanium dioxide without AgNPs. We concluded that the titanium dioxide coatings modified with silver nanoparticles had a high antibacterial activity. Moreover, we demonstrated strong dependence between surface areas of AgNPs and inhibition of bacterial growth. The obtained results evidence that the surface area of AgNPs grown on titanium dioxide coatings is a major factor determining their antimicrobial potential

Tunable Functionality and toxicity studies of Titanium Dioxide Nanotube Layers

In this work, we have developed economic process to elaborate scalable titanium dioxide nanotube layers which show a tunable functionality. The titanium dioxide nanotube layers was prepared by electrochemical anodization of Ti foil in 0.4 wt% hydrofluoric acid solution. The nanotube layers structure and morphology were characterized using x-ray diffraction and scanning electron microscopy. The surface topography and wettability was studied according to the anodization time. The sample synthesized while the current density reached a local minimum displayed higher contact angle. Beyond this point, the contact angles decrease with the anodization time. Photo-degradation of acid orange 7 in aqueous solution was used as a probe to assess the photo-catalytic activity of titanium dioxide nanotube layers under UV irradiation. We obtained better photocatalitic activity for the sample elaborate at higher current density. Finally we use the Ciliated Protozoan T. pyriformis, an alternative cell model used for in vitro toxicity studies, to predict the toxicity of titanium dioxide nanotube layers in biological system. We did not observe any characteristic effect in the presence of the titanium dioxide nanotube layers on two physiological parameters related to this organism, non-specific esterases activity and population growth rate

An investigation into the effect of thickness of titanium dioxide and gold-silver nanoparticle titanium dioxide composite thin-films on photocatalytic activity and photo-induced oxygen production in a sacrificial system

Thin films of titanium dioxide and titanium dioxide with incorporated gold and silver nanoparticles were deposited onto glass microscope slides, steel and titanium foil coupons by two sol–gel dip-coating methods. The film's photocatalytic activity and ability to evolve oxygen in a sacrificial solution were assessed. It was found that photocatalytic activity increased with film thickness (from 50 to 500 nm thick samples) for the photocatalytic degradation of methylene blue in solution and resazurin redox dye in an intelligent ink dye deposited on the surface. Contrastingly, an optimum film thickness of [similar]200 nm for both composite and pure films of titanium dioxide was found for water oxidation, using persulfate (S2O82−) as a sacrificial electron acceptor. The nanoparticle composite films showed significantly higher activity in oxygen evolution studies compared with plain TiO2 films

Ammonia sensing using lossy mode resonances in a tapered optical fibre coated with porphyrin-incorporated titanium dioxide

The development of an ammonia sensor, formed by the deposition of a functionalised titanium dioxide film onto a tapered optical fibre is presented. The titanium dioxide coating allows the coupling of light from the fundamental core mode to a lossy mode supported by the coating, thus creating lossy mode resonance (LMR) in the transmission spectrum. The porphyrin compound that was used to functionalise the coating was removed from the titanium dioxide coating upon exposure to ammonia, causing a change in the refractive index of the coating and a concomitant shift in the central wavelength of the lossy mode resonance. Concentrations of ammonia as small as 1ppm was detected with a response time of less than 1min. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Magnesium-zinc reduction is effective in preparation of metals

Uranium, thorium, and plutonium are effectively prepared by magnesium-zinc reduction, using uranium oxides, thorium dioxide, and plutonium dioxide as starting materials. This technique is also useful in performing reduction of metals such as zirconium and titanium

Effect of Annealing Temperature On Iron Doped Titanium Dioxide Thin Films Prepared By Spin Coating Technique

Iron (Fe) doped titanium dioxide (TiO2) thin films have been successfully deposited by using spin coating technique. X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) were employed to characterize the microstructure and crystallite morphology of the films. It was indicated that the rutile crystal orientation appears due to increasing annealing temperature of the thin films. Furthermore, increasing annealing temperature of the thin films yielded an increasing of porosity value which is related to the application on gas sensor films. Keywords: Iron doped titanium dioxide, Spin coating, Porosity valu

Photodegradation and Adsorption of Fast Green FCF in Tio2-Chitin Suspension

The potential of chitin as co-adsorbent in the photocatalytic degradation of Fast Green in titanium dioxide suspension was investigated. The physico-chemical characteristics of chitin were studied using Analysis of Surface Area and Porosity (ASAP), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The sorption study was first done and compared with titanium dioxide heterogeneous photocatalysis. The result of kinetics studies indicates that the sorption process was pH dependent and exothermic. The adsorption equilibrium was achieved after 60 minutes and the adsorption capacity increased as the dye concentration was increased. The kinetic data was tested for first and pseudo-second kinetic order models and was found to fit well to the latter, while the adsorption isotherm was found to agree well with the Langmuir equation assuming monolayer type adsorption.The photocatalytic degradation and adsorption of Fast Green from aqueous solution has been investigated in suspensions containing commercial titanium dioxide (Degussa P-25), chitin and mixture of titanium dioxide-chitin. The removals of Fast Green using a mixture of titanium dioxide-chitin were found to follow first order kinetic. The presence of chitin in titanium dioxide suspension enhanced the removal by two times higher. Fast Green removal using mixture of titanium dioxide-chitin under UV irradiation was found to be more efficient rather than illumination using titanium dioxide or chitin alone. The removal of Fast Green using chitin and a mixture of titanium dioxide-chitin were rapid for the first 30 minute and reached equilibrium after 1 hour. A synergy effect was observed with an increase in the apparent rate constant by 1.86 times. This was ascribed to an extended adsorption of Fast Green on chitin followed by a transfer to titanium dioxide where it is photocatalytically degraded. pH has significant effect on the adsorption and photodegradation properties of chitin and titanium dioxide surface. However, the effect of temperature on adsorption and photodegradation process using titanium dioxide-chitin mixture was minimal. This combined photocatalytic-adsorption system appears promising as an efficient accelerated removal process of organic pollutants from water

The Effects of Cationically Charged Titanium Dioxide on Particle Dispersion in the Sheet of Paper

Comercial bleached soft wood sulfite pulp was used. The pulp was refined in a Standard Valley Beater to a Canadian Standard freeness of 428. This pulp was preserved and used to make all of the handsheets, on a Noble and Wood handsheet mold. The Titanium dioxide added to the handsheets was prepared in three different ways: simple dispersion, dispersion of the Titanium dioxide along with cationic substances, and addition of the dispersed Titanium dioxide and the cationic substance to the pulp without previous co-dispersion. The optical properties of the sheets were measured and the Titanium dioxide in the sheets was found by an ash analysis. The scattering coefficient of the Titanium dioxide in the sheets was then determined with the Judd chart of the Kubelka-Munk equation. The percents of retention were also determined. The results also indicate that there are optimum percent levels of cationic polyamide (PA) based on the weight of Titanium dioxide. At one percent level the method of co-dispersion can produce a three dollar per ton of five percent Titanium dioxide paper savings. The savings over using un-treated Titanium dioxide is about six dollars per ton on a run of paper which was five percent un-treated Titanium dioxide