The reaction of titanium dioxide with hydrofluoric acid

Buslaev, Yu. A.; Bochkareva, V. A.; Nikolaev, N. S.

doi:10.1007/bf00909521

Cited by 19 publications

(13 citation statements)

References 4 publications

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“…HF and HF/HNO 3, commonly used for surface preparation of biomedical implants, result in dramatic differences in the surface morphology, composition and topography of both CG and nanostructured Ti. The HFpickling produces a relatively rough surface in both cases (Figure 3), due to intensive dissolution of Ti [25]. Visually, the surface of the materials has dull appearance.…”

mentioning

confidence: 95%

Electrochemical Anisotropy of Nanostructured Titanium for Biomedical Implants

Matykina

Arrabal

Valiev

et al. 2015

Electrochimica Acta

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mentioning

confidence: 95%

Electrochemical Anisotropy of Nanostructured Titanium for Biomedical Implants

Matykina

Arrabal

Valiev

et al. 2015

Electrochimica Acta

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“…An analogous species, TiOF + , is considered to be stable in solutions of titanium and fluoride ions. 21 The absence of zirconium species in the anodic films contrasts with the deposition of zirconium oxide during formation of conversion coatings on aluminum alloys in baths containing fluorozirconate ions. The deposition is favored at cathodic sites on the alloy surface where the pH is locally increased by reduction of oxygen, resulting in the reaction: On the contrary, during anodizing, the anodic oxidation of the aluminum generates increased acidity according to the reaction:…”

Section: Resultsmentioning

confidence: 99%

Influence of Fluorozirconic Acid on Sulfuric Acid Anodizing of Aluminum

Elaish¹,

Curioni

Gowers³

et al. 2017

J. Electrochem. Soc.

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The effects of additions of fluorozirconic acid to sulfuric acid on the anodizing behavior of aluminum have been investigated under a constant voltage at temperatures of 0 and 20 • C. The fluoroacid increased the rate of film growth, with a dependence on the fluoroacid concentration, the electrolyte temperature and the anodizing time. Compositional analyses showed that fluorine species were present in the films. However, zirconium species were absent. The fluoroacid generally enhanced film dissolution, although this effect was less important at low fluoroacid concentration, low electrolyte temperature and short anodizing times. Chromium (VI)-free conversion treatments that include fluorotitanic and fluorozirconic acids in the bath formulations have been developed for aluminum alloys.1-6 The resultant coatings comprise chromium (III) (if present in the bath), titanium and zirconium fluorides, oxides and hydroxides, which constitute the main part of the coating thickness, and a comparatively thin layer of aluminum oxyfluoride next to the substrate. In comparison with the findings from the relatively numerous studies of conversion coatings produced using fluoroacids, very little information is available on the use of fluoroacids in anodizing of aluminum and aluminum alloys. One study has been made of anodizing aluminum and aluminum alloys at a constant current density in fluoroboric acid solutions at temperatures ranging from 0 to 30• C. 7 Porous films were formed, with a pore size and population density that depended on the concentration and temperature of the fluoroboric acid solution and the time of anodizing. However, the information provided on the morphology and composition of the films was very limited and the role of the fluoroacid in the growth of the film was not considered. More recent studies examined the influence of ammonium hexafluorosilicate 8 and ammonium fluoride 8,9 additions to oxalic acid on the formation of porous anodic films on aluminum. The effect of hexafluorosilicate ions was more pronounced than that of fluoride ions, suggesting that Si

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“…This is because the N-F-co-doping of TiO 2 can generate F ions in system that can form an F complex with Ti to fluorotitanic acid compounds such as H[TiF 4 (OH)H 2 O], H[TiF 5 ÁH 2 0], and HÁ[TiF 6 ] in solution form. Hence, increasing the N-F-doping degree can reduce the formation of TiO 2 nanoparticle-impregnated BC nanofibers (Buslaev et al 1962).…”

Section: Crystallographic Formmentioning

confidence: 99%

Photocatalytic disinfection of water by bacterial cellulose/N–F co-doped TiO2 under fluorescent light

2015

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The hybrid nanocomposite material of bacterial cellulose (BC) nanofibers and titaniumdioxide (TiO 2 ) nanoparticles with improved visible light sensitivity was developed by doping nitrogen (N) and fluorine (F) on TiO 2 nanoparticles embedded on BC nanofibers. To synthesize TiO 2 nanoparticles on BC produced by Acetobacter xylinum (TISTR 975), titanium tetraisopropoxide (TTIP) was used as a titanium source and was directly hydrolyzed on BC nanofibers. After providing heat via the reflux technique to BC/TiO 2 pellicle, the crystalline structure of TiO 2 was changed to an anatase form on a three dimensional network structure of BC confirmed by XRD. Nitrogen (N) and fluorine (F) were successfully doped into TiO 2 nanoparticles by using NH 4 F as the source of N and F (BC/N-F-co-doped TiO 2 ). The TEM results showed that the average particle size of BC/N-F-codoped TiO 2 was smaller than the BC matrix containing none of the co-doped TiO 2 (BC/TiO 2 ) and N-doped TiO 2 (BC/N-TiO 2 ). In addition, BC/ N-F-co-doped TiO 2 demonstrated the high efficiency of photocatalytic disinfection activity against both gram-negative and gram-positive bacteria under fluorescence light. Nevertheless, the photocatalytic antibacterial activity of N-F-co-doped TiO 2 also depended on the type of bacteria, and degree of N-F-co-doped TiO 2 .

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The reaction of titanium dioxide with hydrofluoric acid

Cited by 19 publications

References 4 publications

Electrochemical Anisotropy of Nanostructured Titanium for Biomedical Implants

Electrochemical Anisotropy of Nanostructured Titanium for Biomedical Implants

Influence of Fluorozirconic Acid on Sulfuric Acid Anodizing of Aluminum

Photocatalytic disinfection of water by bacterial cellulose/N–F co-doped TiO2 under fluorescent light

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