scholarly journals Plasma-Induced Crystallization of TiO2 Nanotubes

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 626 ◽  
Author(s):  
Metka Benčina ◽  
Ita Junkar ◽  
Rok Zaplotnik ◽  
Matjaz Valant ◽  
Aleš Iglič ◽  
...  

Facile crystallization of titanium oxide (TiO2) nanotubes (NTs), synthesized by electrochemical anodization, with low pressure non-thermal oxygen plasma is reported. The influence of plasma processing conditions on TiO2 NTs crystal structure and morphology was examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). For the first time we report the transition of amorphous TiO2 NTs to anatase and rutile crystal structures upon treatment with highly reactive oxygen plasma. This crystallization process has a strong advantage over the conventional heat treatments as it enables rapid crystallization of the surface. Thus the crystalline structure of NTs is obtained in a few seconds of treatment and it does not disrupt the NTs’ morphology. Such a crystallization approach is especially suitable for medical applications in which stable crystallized nanotubular morphology is desired. The last part of the study thus deals with in vitro biological response of whole blood to the TiO2 NTs. The results indicate that application of such surfaces for blood connecting devices is prospective, as practically no platelet adhesion or activation on crystallized TiO2 NTs surfaces was observed.

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2121
Author(s):  
Vinsensia Ade Sugiawati ◽  
Florence Vacandio ◽  
Thierry Djenizian

All-solid-state batteries were fabricated by assembling a layer of self-organized TiO2 nanotubes grown on as anode, a thin-film of polymer as an electrolyte and separator, and a layer of composite LiFePO4 as a cathode. The synthesis of self-organized TiO2 NTs from Ti-6Al-4V alloy was carried out via one-step electrochemical anodization in a fluoride ethylene glycol containing electrolytes. The electrodeposition of the polymer electrolyte onto anatase TiO2 NTs was performed by cyclic voltammetry. The anodized Ti-6Al-4V alloys were characterized by scanning electron microscopy and X-ray diffraction. The electrochemical properties of the anodized Ti-6Al-4V alloys were investigated by cyclic voltammetry and chronopotentiometry techniques. The full-cell shows a high first-cycle Coulombic efficiency of 96.8% with a capacity retention of 97.4% after 50 cycles and delivers a stable discharge capacity of 63 μAh cm−2 μm−1 (119 mAh g−1) at a kinetic rate of C/10.


2009 ◽  
Vol 1178 ◽  
Author(s):  
Yahya Alivov ◽  
Vladimir Kuryatkov ◽  
Mahesh Pandikunta ◽  
Gautam Rajanna ◽  
Daniel Johnstone ◽  
...  

AbstractIn this work we investigated the structural, electrical, and optical properties of titanium dioxide (TiO2) nanotubes (NTs) formed by electrochemical anodization of Ti metal sheets in NH4F+glycerol electrolyte at different anodization voltages (Va) and acid concentrations. Our results revealed that TiO2 NTs can be grown in a wide range of anodization voltages from 10 V to 240 V. The maximum NH4F acid concentration, at which NTs can be formed, decreases with the anodization voltage, which is 0.7% for Va<60V, and decreases to 0.1% at Va =240 V. Glancing angle X-ray diffraction (GAXRD) experiments show that as-grown amorphous TiO2 transforms to anatase phase after annealing at 400 oC, and further transforms to rutile phase at annealing temperatures above 500 oC. Samples grown in 30-120 voltage range have higher crystal quality as seen from anatase (101) peak intensity and reduced linewidth. The electrical resistivity of the NTs varies with Va concentration and increases by eight orders of magnitude when Va increases from 10 V to 240 V. This is consistent with cathodoluminescense studies which showed improved optical properties for samples grown in this voltage range. Optical properties of samples were also studied by low temperature photoluminescence. Temperature dependent I-V and photo-induced current transient spectroscopy were employed to analyze electrical properties and defect structure on NT samples.


Planta Medica ◽  
2018 ◽  
Vol 84 (14) ◽  
pp. 1013-1021 ◽  
Author(s):  
Jun-Bo Gao ◽  
Xing-Jie Zhang ◽  
Rui-Han Zhang ◽  
Li-Li Zhu ◽  
De-Bing Pu ◽  
...  

AbstractFour new dolabellane-type diterpene alkaloids, glandulamines A – D (1 – 4), together with twelve known compounds (5 – 16), were isolated from the seeds of Nigella glandulifera using repeated column chromatography and semipreparative HPLC. The structures of 1 – 16 were elucidated based on NMR data analysis, HRMS experiments and other spectroscopic interpretations. The absolute configuration of 5 was determined by single-crystal X-ray diffraction data for the first time. Compounds 10 and 12 showed human dihydroorotate dehydrogenase inhibitory activity with IC50 values of 61.1 ± 5.3 and 45.9 ± 3.0 µM, respectively. Molecular docking of the active compound 12 and positive control teriflunomide on the inhibitor-binding site of human dihydroorotate dehydrogenase was subsequently performed to visualize the interaction pattern. In addition, compounds 8 and 10 exhibited inhibitory effects against lipopolysaccharide-induced nitric oxide production with inhibition rates of 61 and 41%, respectively, at the concentration of 10 µM. Compounds 9 and 12 showed cytotoxic activities with cell viability varying from 29 ~ 57% at 100 µM against T98G, U87, U251, and GL261 glioma cancer cell lines. These data provide new insights on the pharmacologically active compounds of this plant widely used in folk medicine.


2006 ◽  
Vol 309-311 ◽  
pp. 367-370 ◽  
Author(s):  
E.T. Uzumaki ◽  
A.R. Santos ◽  
C.S. Lambert

Plasma immersion process was investigated as a method for producing bioceramics coatings on metallic implants due to its advantages, which include the production of coatings on three-dimensional workpieces, with high density and superior adhesion. In this process, the oxygen plasma was utilized to form titanium oxide on titanium substrate. The structure, composition and surface morphology were studied using scanning electron microscopy (SEM) and X-ray diffraction. In addition a preliminary study has also been carried out, on TiO2-coated and uncoated titanium substrates, to analyse the in vitro biocompatibility (cytotoxicity evaluation and cell morphology).


Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2714
Author(s):  
Mario Bohač ◽  
Tihana Čižmar ◽  
Vedran Kojić ◽  
Jan Marčec ◽  
Krunoslav Juraić ◽  
...  

A novel low-cost synthesis of barium-modified TiO2 nanotube (TNT) arrays was used to obtain an immobilized photocatalyst for degradation of diclofenac. TNT arrays were prepared by electrochemical anodization of titanium thin films deposited on fluorine-doped tin oxide (FTO) coated glass by magnetron sputtering, ensuring transparency and immobilization of the nanotubes. The Ba-modifications were obtained by annealing solutions of Ba(OH)2 spin coated on top of TNT. Three different concentrations of Ba(OH)2 were used (12.5 mM, 25 mM and 50 mM). The crystalline structure, morphology and presence of Ba were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy, respectively. Ba-modified TiO2 nanotubes (BTNT) were tested for photocatalytic degradation of diclofenac under UV/Vis radiation and it was proven that all of the Ba-modified samples showed an increase in photocatalytic activity with respect to the unmodified TNTs. The most efficient photocatalyst was the sample prepared with 25 mM Ba(OH)2 which showed 90% diclofenac degradation after 60 min. This result was in agreement with cyclic voltammetry measurements that showed the largest increase in photo-oxidation current densities for the same sample due to the increased generation of •OH radicals obtained by a more efficient photogenerated charge separation.


2012 ◽  
Vol 620 ◽  
pp. 325-329 ◽  
Author(s):  
Nur Hidayati Ahmad Barudin ◽  
Srimala Sreekantan ◽  
Ong Ming Thong ◽  
Lam Kit Lay

The in vitro cell response was investigated on flat Ti surface vs nanostructured TiO2 nanotube surface. The titanium dioxide nanotube layers were prepared by electrochemical anodization of Ti in ethylene glycol, 5 wt% NH4F and 1ml H2O2. The nanotube layered structure and morphology were characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The diameter and the length of the nanotubes are found to increase with anodization voltage. Hs27 and breast cancer cell line MCF-7 were used for cell interaction studies. Different surfaces of titanium show variation in term of growth and viability of cells. Different cell type also show different cellular responses to these surfaces. Titanium nanotube with tube diameter 90 nm promoted normal cell adherence and spreading but killed the cancer cells. The detail of the observation is discussed thoroughly in this paper.


2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Roghayeh Haghjoo ◽  
Seyed Khatiboleslam Sadrnezhaad ◽  
Nahid Hasanzadeh Nemati

: The present study applied a TiO2 nanocoating on a titanium foam substrate produced by powder metallurgy through magnetron sputtering. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) were employed to investigate the surface morphologies of the porous specimens and pre- and post-coating phases, respectively. Also, the growth and proliferation of MG-63 cells (osteoblasts) and their attachment and proliferation on the coated porous titanium specimen (relative to the uncoated specimens) were studied using in vitro and methyl thiazol tetrazolium (MTT) cytotoxicity tests. Considering the porous macrostructure of the coated titanium specimen and the nanostructure of the TiO2 coating on the porous surface and macro-pore walls, the coated specimen was found to be effective in the biocompatibility improvement of dental and orthopedic implants.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2359
Author(s):  
Jung Park ◽  
Anisoara Cimpean ◽  
Alexander B. Tesler ◽  
Anca Mazare

TiO2 nanostructures and more specifically nanotubes have gained significant attention in biomedical applications, due to their controlled nanoscale topography in the sub-100 nm range, high surface area, chemical resistance, and biocompatibility. Here we review the crucial aspects related to morphology and properties of TiO2 nanotubes obtained by electrochemical anodization of titanium for the biomedical field. Following the discussion of TiO2 nanotopographical characterization, the advantages of anodic TiO2 nanotubes will be introduced, such as their high surface area controlled by the morphological parameters (diameter and length), which provides better adsorption/linkage of bioactive molecules. We further discuss the key interactions with bone-related cells including osteoblast and stem cells in in vitro cell culture conditions, thus evaluating the cell response on various nanotubular structures. In addition, the synergistic effects of electrical stimulation on cells for enhancing bone formation combining with the nanoscale environmental cues from nanotopography will be further discussed. The present review also overviews the current state of drug delivery applications using TiO2 nanotubes for increased osseointegration and discusses the advantages, drawbacks, and prospects of drug delivery applications via these anodic TiO2 nanotubes.


2018 ◽  
Vol 50 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Jelena Vujancevic ◽  
Andjelika Bjelajac ◽  
Jovana Cirkovic ◽  
Vera Pavlovic ◽  
Endre Horvath ◽  
...  

One-dimensional (1D) TiO2 nanotubes perpendicular to the substrate were obtained by electrochemical oxidation of titanium foil in an acid electrolyte. In order to alter the crystallinity and the morphology of films the as-anodized amorphous TiO2 nanotube films were sintered at elevated temperatures. The evolution of the morphology was visualized via scanning electron microscopy (SEM), while the crystalline structure was investigated by X-ray diffraction (XRD) and Raman spectroscopy. The chemical composition was studied by X-ray photoelectron spectroscopy (XPS). The effects of crystallinity and morphology of TiO2 nanotube (NTs) films on photocatalytic degradation of methyl orange (MO) in an aqueous solution under UV light irradiation were also investigated. The TiO2 nanotubes sintered at 650?C for 30 min had the highest degree of crystallinity and exhibited the best photocatalytic activity among the studied TiO2 nanotube films.


Sign in / Sign up

Export Citation Format

Share Document