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Introduction: Intentional replantation is a recognized endodontic procedure in cases in which root canal and surgical endodontic treatments are not recommended. Although not frequently used, intentional replantation is a treatment option that dentists should consider. Three keys point should be keep in mind to ensure the success of replantation procedure. To overcome any complications, the surgical procedure have to be rigorous, the extra-alveolar time properly managed, and the splint adapted. In the other hand, the knowing of the indications and the advantages is advocated for the success of this procedure. Conclusion: When standard protocols of intentional replantation are followed, clinical and radiological success is expected. From this point of view, intentional replantation should be considered as a viable therapeutic and not as a procedure of last resort

This paper examines the use of TiO2 nanotubes (HNTs) as supports for V2O5 based catalysts in the total oxidation of chlorobenzene. The effect of the addition of SO42− onto the support is also discussed. Vanadium was introduced either by direct incorporation of V during the elaboration of the nanotubes (in situ elaboration), or by the impregnation of V on the surface of the supports (ex situ elaboration). The obtained catalysts have been characterized by means of ICP-AES, N2 adsorption–desorption at 77K, XRD, DRIFTS, XPS, H2-TPR and NH3-TPD. We demonstrated that sulfating step highly improves the catalytic performances of V-HNTs catalysts. This is due to an increased global acidity and a higher reactivity of redox sites thanks to the electronic interaction between sulfated titania and VOx species. Moreover, it seems that the ‘in situ’ or ‘ex situ’ elaboration route of sulfated V-catalysts influences the environment of vanadium species. In particular, the ‘in situ’ route leads to a more efficient catalyst.

AIR:EAU:RAFFINAGE:MATERIAUX+ATR:HKO:CGU:GBE; The influence of the sodium content on thermal stability and photocatalytic activity of calcined titanate nanotubes (TNT) was herein evaluated by preparing different samples through hydrothermal treatment of TiO2 powder (P25) in a concentrated NaOH solution (11.25 M) at 130 degrees C during 20 h followed by acid washing steps. Titanate nanotubes samples with sodium (Na-TNT) and sodium-free (H-TNT) were then obtained using different concentrations of HCI aqueous solutions namely 0.1 M and 1 M respectively. As synthesized nanomaterials with different Na percentages were then calcined at temperatures varying between 400 degrees C and 700 degrees C. Samples were characterized by means of nitrogen adsorption-desorption isotherms at 77 K, thermal analysis (DTA, TGA), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, and diffuse reflectance spectroscopy (DRS). The photocatalytic activities of Na-TNT and H-TNT derived nanomaterials were then evaluated through the photocatalytic degradation of formic acid (FA). Results show that the presence of sodium retards the dehydration process during the transformation of titanate into TiO2 shifting the formation of anatase phase to higher temperatures. However, sodium is not necessary to preserve the nanotubular morphology. The presence of sodium after calcination strongly impacts negatively the photocatalytic properties. If sodium is completely removed from the initial titanate orthorhombic phase, calcination leads to TiO2 anatase materials with enhanced photocatalytic properties compared to P25 in the degradation of formic acid, particularly if nanotubular morphology is preserved. The highest activity was therefore achieved for the H-TNT sample calcined at 400 degrees C. The photodegradation activity of formic acid depends on the specific surface areas and TiO2 crystallinity. In pure anatase nanoparticles the activity strongly decreases with coherent crystallographic domains >= 10 nm. (c) 2013 Elsevier B.V. All rights reserved.

SSCI-VIDE+CARE:ECI2D+MME:ATR:HKO:CGU:GBE; International audience; The influence of lanthanum on the thermal stability and photocatalytic activity of calcined hydrogenotitanate nanotubes (HNT) was hereinevaluated. HNT samples were prepared through the hydrothermal treatmentof TiO2 P25 in a concentrated NaOH solution (11.25 M) at 130 degrees Cduring 20 h followed by acid washing. La-doped titanates nanotubes(La-HNT) photocatalysts with optimum 1 wt% of La were then elaborated byincipient wetness impregnation method using lanthanum nitrate asprecursor. La HNT and HNT samples were then calcined at temperaturesvarying between 400 degrees C and 700 degrees C. Samples werecharacterized by means of nitrogen adsorption-desorption isotherms at77K, X-ray diffraction (XRD), Raman spectroscopy, diffuse reflectancespectroscopy (DRS), photoluminescence spectroscopy (PL), transmissionelectron microscopy (TEM), ICP analysis and photocurrent experiments.The photocatalytic activities of La-HNT and HNT derived nanomaterialswere then evaluated through the photocatalytic degradation of formicacid (FA).Main results reveal that lanthanum inhibits TiO2 crystallite growthand retards anatase transformation into the less active rutile phase.The addition of La ions to TiO2 results in a charge imbalance creating ahigh proportion of oxygen vacancies as evidenced by photocurrent,photoluminescence and Raman experiments.The photocatalytic experiments reveal that La-doped TiO2 helps tomaintain a high photocatalytic activity level even after calcination athigh temperatures contrary to La-free photocatalysts. The determinationof kinetic parameters reveals that the maintaining of a highphotocatalytic activity results from the synergetic effect betweenrestriction of TiO2 crystallite size growth and formation of a highproportion of oxygen vacancies.

AIR:EAU:RAFFINAGE:MATERIAUX+ATR:CGU:FDA:GBE:HKO; 1D-TiO2 nanomaterials (nanotubes, nanorods, nanoplates, nanospheres and nanoparticles) with tuned structural and textural properties have been evaluated in the photocatalytic degradation of formic acid (FA) under UV conditions. The FA adsorption isotherms follow the model of Langmuir and the kinetic of FA photodegradation shows Langmuir-Hinshelwood model whatever the TiO2 morphologies. TiO2 nanotubes (HTNT-400), nanoplates (HTNW-700) and nanoparticles (HTNT-500 and HTNT-600) show an interesting photocatalytic activities compared to TiO2 nanospheres (P25) and nanorods (TNR). The nanotubular TiO2 (HTNT-400) has a photocatalytic activity 4 times higher than TiO2 P25. The enhanced activity is attributed to the smaller crystallite size of anatase and tuned surface area of the photocatalyst. The pH study showed that the coexistence of HCOO- and HCOOH species at natural pH (ca. 3.5) is favourable for better adsorption on active sites of titanium oxide nanomaterials and consequently to a better photocatalytic activity. (C) 2014 Elsevier B.V. All rights reserved.

AIR:EAU:RAFFINAGE:MATERIAUX+HKO:CGU:GBE; Photocatalysis is a well known efficient process for the decontamination of wastewaters pollutants. In the last decade an intense research was focused on the elaboration of well tuned TiO2 photocatalysts with the basic idea to understand the relationship between exposed facet and reactivity. In this work, four TiO2 morphologies are examined namely: nanotubes (NT), nanoplates (NPL), nanorods (NR) and nanospheres (NS). The solar photocatalytic properties are compared in the disinfection of a Fusarium solani inoculated solution. Disinfection using the solar light has been studied and the effect of formic acid (FA) was examined. We demonstrated, for the first time, that the solar inactivation of the resistant spores of Fusarium in water is related to the exposed TiO2 facets. At very low concentration of photocatalyst, the inactivation of F. solani over TiO2 nanospheres shows the best disinfection efficiency with respect to the others morphologies. Experiments on simultaneous photocatalytic decontamination of FA and inactivation of F. solani showed that the presence of FA strongly retards the disinfection reaction in the case of TiO2 nanospheres while the FA degradation occurred simultaneously with F. solani inactivation in the case of TiO2 NT. This result shows the interest of TiO2 NT for the decontamination and disinfection of wastewaters containing acidic pollutants and pathogens. (C) 2012 Elsevier B.V. All rights reserved.

1 D TiO2 nanomaterials (nanotubes, nanowires) were synthesized through hydrothermal treatment of TiO2 powder (P25) in concentrated alkaline solutions (NaOH for nanotubes, KOH for nanowires) followed by calcination at varying temperatures between 400°C and 700°C. Samples were characterized by HRTEM, XRD, Raman spectroscopy, and N2 adsorption-desorption isotherms. High surface area nanotubular TiO2 materials can maintain their 1D morphology up to a temperature of calcination of 400°C while changing their phase from hydrogenotitanate to anatase. The use of KOH leads to a retarded formation of anatase. Photocatalytic results showed that TiO2 anatase nanotubes calcined at 400°C can degrade formic acid with a rate constant four times higher than for P25. A direct correlation between surface area and photocatalytic activity explains the much higher activity of TiO2 anatase nanotubes. On the opposite, for the degradation of phenol, P25 remains more active. In the disinfection of water, contrary to P25, the high surface area of TiO2 nanotubes allows the simultaneous degradation of formic acid and the inactivation of pathogen fungus showing the interest of such materials for the treatment of wastewater.

Pd- and Fe/Pd-HNT were elaborated by successive ionic exchange and wet impregnation at room temperature of hydrogenotitanate nanotubes (HNT) nanomaterials. Hydrogen peroxide was generated in situ via reaction of oxygen and formic acid (FA) over Fe/Pd-HNT catalysts. A high p-hydroxybenzoic acid (p-HBz) mineralization was achieved (52%) using Fe/Pd-HNT/FA/O2/UV system compared to the simulated reaction using Fe/Pd-HNT/H2O2/UV system (34%). The rate of hydrogen peroxide formation over Pd-HNT catalyst, during in situ generation, probably plays a key role in controlling the kinetics of the p-HBz degradation.

Hydrogenotitanates (HNTs) nanotubes with different diameters were prepared by hydrothermal treatment of TiO(2) (P25) followed by washing with HCl aqueous solution. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermal analysis and N(2) adsorption/desorption. In order to determine the palladium uptake ability of different HNT samples, the interaction between HNTs and Pd(II) was subsequently studied in aqueous solution at pH 9 (NH(+)(4)/NH(3) buffer). Transmission electron microscopy showed that the diameter of the nanotubes depends on the preparation conditions. Chemical analysis of residual sodium and thermal studies showed that the chemical formula of the two prepared HNT was H(x)Na(2-x)Ti(2)O(5)H(2)O with x=1.61 or 1.65. The HNTs are mesoporous materials with a multi-walled nanotubular structure and high specific surface area. In order to determine the capacity of palladium retention of different HNTs samples, the interaction between HNTs and Pd(II) was subsequently studied in aqueous solution at pH 9 (NH(+)(4)/NH(3) buffer). The adsorption kinetics of Pd(II) on the HNTs was very fast. The isotherms of Pd(II) on the HNTs showed that the adsorption occurred (1) initially through cationic exchange and (2) when the concentration of Pd(II) is high by precipitation of different Pd salts. The adsorption capacity of Pd(II) is strongly altered by the morphology of the HNTs samples.