Ti Peaks Research Articles

Microstructure and Wettability of Graphene Oxide/TiO2 Thin Film Prepared via Sol-gel Method

The microstructure of graphene oxide TiO2 (GO/TiO2) films on wettability and morphology properties were studied at different amount of Titanium isopropoxide with fixed amount of GO. GO/TiO2 thin films were prepared by using sol-gel method and deposited on glass substrate by spin-coating technique. The formation of GO/TiO2 was confirmed by using Fourier Transform Infrared Spectroscopy (FTIR) study while the morphology of GO/TiO2 was observed by Scanning Electron Microscopy (SEM) analysis. The hydrophilic/hydrophobic interactions of these films were examined by wettability test by measuring the water contact angle of the water drop on the surface of the coating. The wettability tests display that the contact angle of GO/TiO2 was increased from 90.0º to 118.7º after reduce the amount of titanium isopropoxide (TTIP). A small peaks of graphene and Ti were observed in the coated films and more pronounce peaks occur after the films were annealed. However, it was found that the annealing process does not improve the contact angle of the films as compared to the non-annealed films.

Rapid identification of Sr on surfaces of metals, porous medium, transparent materials using single-shot laser-induced breakdown spectroscopy

Rapid threat analysis is essential in radiological terror scenes to protect workers and the public. 90Sr, a potential dirty bomb material, has been stolen multiple times. A conventional radiation detection is slow for detecting 90Sr that only emits β-ray. It rigorously interacts with matters and rarely reaches a detector. For fast analysis over large area after confirming the presence of radioactive Sr, laser-induced breakdown spectroscopy can be an attractive method. This study investigates the effect of different substrates on identifying Sr on their surface using single-shot. The thin layer of Sr on the forensic samples makes the single-shot analysis essential. The substrates include metallic (aluminium, stainless steels), porous (mortar, polyester), and transparent materials (poly(ethyl benzene-1, 4-dicarboxylate)). SrCO3, SrTiO3, and SrF2 are 3 target compounds selected based on historical theft cases. The limits of detection range over 1.09–19.06 μg/cm2. Stainless steel shows the lowest LOD at 407.77 nm for SrCO3 and SrF2. Higher standard error is explained by more heterogeneous Sr distribution. The transparent material shows the highest error. Additionally, potential ways to distinguish chemical compounds are suggested using Ti peaks and SrF vibration band. The applicability is discussed by comparing surface concentrations of Sr from terror and natural background.

Preparation and Characterization of TiO2-SiO2 Bioceramic Coating on Ti Alloy via Electrochemical Anodization and Its Effect on Corrosion Resistance

AbstractPurpose: The present study was carried out to study changing the anodization parameters and investigate the corrosion resistance of the ceramic coating that will be formed on the CP-Ti by anodization method. Materials and Methods: CP-Ti (10mm×10mm×2mm) were used for fabrication of bioceramic coating through anodization with different parameters using potassium silicate electrolyte. Samples were characterized using XRD, AT-FTIR. Surface roughness was measured using ESEM and surface topography was evaluated by SEM. Tafel polarization and electrochemical impedance spectroscopy were used to detect the change in the corrosion resistance after anodization. Results: XRD revealed that the anodized coated samples showed well defined peaks of Ti and TiO2 and shallow peaks of SiO2. AT-FTIR showed stretching bands of titania and silica. Surface roughness results: anodized coated samples at the optimum conditions had the lowest Ra values while the uncoated group had the highest Ra value. Results of the surface morphology: best evenly distributed ceramic coat was formed at the optimum conditions where (the applied voltage =50v, the electrolyte concentration =3% and process duration=60min). Corrosion resistance of the anodized coated samples at the optimum conditions was markedly increased more than that of the uncoated CP-Ti. Conclusions:optimum conditions of the anodization process to get a uniform anodized coating can be achieved when; the applied voltage is 50v, the electrolyte concentration is 3% and the process duration in 60min. Moreover, formation of a bioceramic coating has been shown to be a useful method for improving the corrosion resistance.

Use of Pre-treated TiO2 as Cathode Material to Produce Ti Metal Through Molten Salt Electrolysis

Pre-treatment is carried out for partial reduction of TiO2 to lower valence titanium sub-oxides. The compacted pre-treated mass is electrolysed in molten CaCl2 bath at a temperature of 1000 °C for 1–5 h. The characterisations of the samples are carried out by XRD, SEM, EDS and ICP. The XRD analysis of the pre-treated mass shows the peaks of Ti2O3 and Ti4O7 along with retained TiO2 phase. The XRD analysis of the 1-h-electrolysed pre-treated sample shows the presence of various phases such as CaTi2O4, Ti2O3, Ti3O5, TiO, Ti2O and metallic Ti, whereas the same for 5-h-electrolysed sample shows only the peaks of Ti, suggesting complete conversion to metallic Ti. The SEM micrograph of the electrolysed sample shows sintering of produced Ti metal particles to form bigger particles. The chemical analysis of the electrolysed samples shows calcium as the major metallic impurity which is removed by acid washing. The comparative current–time plot for electrolysis of pre-treated TiO2 and TiO2 suggests a significantly low current consumption in case pre-treated TiO2 electrolysis than that of TiO2 electrolysis.

Experimental Investigation of Electrospun Titania Nanofibers: An Applied Voltage Influence

Abstract Electrospun nanofibers are being demanded in energy applications because of their easy and in-expensive fabrication process. In this paper, we present the fabrication of nanofibers at various different voltages 8, 9, 10 and 11kV. The nanofibers fabricated at 11kV could yield diameter 175 nm. Scanning electron microscopy (SEM) investigations confirmed the smooth and randomly aligned nanofibers whereas EDX analysis showed the elemental peaks of Ti and O. X-ray diffraction study revealed the mixed phases of anatase and rutile and FTIR measurement endorsed the stretching peak of Ti-O in the range from 800-500 cm-1.

Corrosion behaviors of bioactive element coatings on PEO-treated Ti-6Al-4V alloys

In this study, the corrosion behaviors of bioactive element coatings on plasma electrolytic oxidation (PEO)-treated Ti-6Al-4V alloys were researched using various instruments for measurement of coated elements from PEO-treated surface in the solution of simulated fluid.For this research, Ti-6Al-4V ELI disks were prepared as the substrates for PEO treatment. PEO treatment was carried out using pulsed DC power supply at 280 V for 3 min in electrolytes containing bioactive ions such as silicon, zinc, manganese, magnesium, strontium, calcium, and phosphorus. To analyze the electrochemical properties of the PEO film as a function of added ions in the electrolyte, potentiodynamic and AC impedance tests were performed using a potentiostat in 0.9% NaCl solution. The alloy surface after performing a corrosion test of the PEO-treated specimen on the Ti-6Al-4V alloy was observed using a field-emission scanning microscope, energy dispersive X-ray spectrometer, and X-ray diffractometer (XRD).When a bioactive element was added during the PEO process, the pore size decreased and a precipitate containing a high Mn content was formed around the pores. The XRD results of the PEO-treated surface with bioactive elements showed that the anatase and HA phase contents increased while the Ti peak intensity decreased. When Mn was added to the electrolyte, a second anodic peak appeared, and the precipitates on the surface and pore edges were dissolved in the 0.9% NaCl solution. The results of AC impedance tests revealed a decrease in the polarization resistance of the PEO-treated surface.

Visible and near-infrared wavelength-selective dielectric reflectors for light management applications

Wavelength selective reflectors have been widely used in lightemitting diodes, microcavities, waveguides, solar cells and many more. This paper presents the preparation and study of TiO2/SiO2 distributed Bragg reflectors. These multilayer structures were prepared by adopting an easy and cost-effective sol-gel spin coating approach. The prepared samples were examined using field-emission scanning microscopy (FESEM), energy dispersive x-ray (EDS) spectroscopy, ultraviolet–visible (UV–vis) spectrophotometry and Fourier transform infrared (FTIR) spectroscopy. The top surface FESEM studies showed the uniform and homogeneous films while cross-sectional analyses evidenced the periodic structures of TiO2 and SiO2 films. The elemental peaks of Ti, O, and Si were confirmed by EDS investigation. FTIR investigation endorsed the stretching vibration peaks of Ti-O-Ti and Si-O-Si bonds. The reflectance of all samples was studied in accordance with numbers of TiO2/SiO2 stacks and the solution aging. However, the dominant shift of the reflection band from visible to near-infrared wavelength was observed in accordance with the solution aging from 20 to 40 h.

Simplified micrometric surface characterization of different implant surfaces available on the Brazilian market

Aim: This study characterized the implant surfaces available on the Brazilian market in terms of topography, chemical composition, and roughness. Methods: The following brands were selected according to their surfaces: Kopp (Ko), Signo Vinces (Sv), Neodent (Ne), Osseotite (Os) NanoTite (Nt), SIN (Si), Titanium Fix (Tf), conventional Straumann (Str), Active SLA (SLA). The morphological analysis and the alloy impurities and implant surface contaminants were analyzed by SEM-EDS. Surface roughness parameters and 3-D reconstructions were obtained by laser microscopy (20x). Two distinct areas were evaluated: i) the cervical portion (no surface treatment), and ii) the middle third (treated surface). Results: The characterization of the implant surfaces by SEM showed morphological differences between the thread geometries and surface morphology at 800x and 2000x magnification. The EDS elemental analysis showed a predominance of titanium (Ti) for all implants. The SLA surface showed only peaks of Ti while other implants brands showed traces of impurities and contaminants including Al, C, PR, F, Mg, Na, Ni, O, P, and SR. The implant surface roughness in the cervical portion did not exceed Ra 0.5–1.0 μm, constituting a minimally rough surface and obtaining acceptable standards for this region. Only Nt, Str, and SLA presented Ra above 2 μm in the middle third area showing a rough surface favorable for osseointegration. Conclusion: This study concluded that there is no established standard for morphology, chemical composition and implant surface roughness that allows a safe comparison between the available dental implant surfaces. National implant brands generally contain more impurities and surface contaminants than their international counterparts and were consequently more sensitive to the surface treatment techniques.

Adhesion and mechanical properties of Ti films deposited by DC magnetron sputtering

Titanium films were deposited on AISI 316L stainless steel substrates by D.C. unbalanced magnetron sputtering, the substrate temperature and deposition time were changed. In this study, the structural characterization was conducted by scanning electronic microscopy (SEM), spectroscopic ellipsometry (SE), X-ray diffraction (XRD) and atomic force microscopy (AFM). Furthermore, mechanical properties were obtained by nanoindentation. Adhesion and wear behavior were evaluated through progressive load scratch test (PLST) and pin-on-disk test, respectively. Titanium films thicknesses within a range of 2.5–4.2μm were obtained, different XRD Ti peaks such as (002), (102) and (103) were identified. Values estimated for hardness were between 7.2 and 8.4GPa, and for Young's modulus they were 126–162GPa. Tensile cracks, compressive and gross spallation failure mechanisms were found with scratch tests. Preferred oriented sample only showed cracks, with a critical load of 2.6N, and exhibited a better wear ratio (~1.5×10−4), which is about two times better than substrate steel. This study provides evidence of how a preferred oriented Ti (002) film exhibits better hardness, adhesion and wear properties.

Titanium Aluminium Nitride and Titanium Boride Multilayer Coatings Designed to Combat Tool Wear

The lifetimes and the premature wear of machining tools impact on manufacturing efficiencies and productivities. A significant proportion of machining tool damage can be attributed to component wear. Here, titanium aluminium nitride (TiAlN) multi-layered with titanium diboride (TiB2) prepared by PVD (Physical Vapour Deposition) sputtering onto H-13 substrates are studied as potential wear-resistant coatings for forging die applications. The TiB2 content has been altered and two-sets of coating systems with a bilayer thickness either less than or greater than 1 μm are investigated by tribological and microstructural analysis. XRD analysis of the multilayers reveals the coatings to be predominately dominated by the TiAlN (200) peak, with additional peaks of TiN (200) and Ti (101) at a TiB2 content of 9%. Progressive loads increasing to 100 N enabled the friction coefficients and the coating failure at a critical load to be determined. Friction coefficients of around 0.2 have been measured in a coating containing 9% TiB2 at critical loads of approximately 70 N. Bi-directional wear tests reveal that bilayers with thicknesses greater than 1 μm have frictional coefficients that are approximately 50% lower than those where the bilayer is less than 1 μm. This is due to the greater ability of thicker bilayers to uniformly distribute the stress within the layers. There are two observed frictional coefficient regimes corresponding to a lower and higher rate of material loss. At the lower regime, with TiB2 contents below 20%, material loss occurs mainly via delamination between the layers, whilst at compositions above this, material loss occurs via a break-up of material into finer particles that in combination with the higher loads results in greater material loss. The measured wear scar volumes for the TiAlN/TiB2 multilayer coatings are approximately three times lower than those measured on the substrate, thus validating the increased wear resistance offered by these composite coatings.

Metavolcanics from Capo Malfatano, SW Sardinia, Italy: New insight on the age and nature of Ordovician volcanism in the Variscan foreland zone

The tectonic/stratigraphic interpretation of the Cambro–Ordovician rocks exposed in the south‐westernmost sectors of the Sardinia island (i.e., belonging to the Bithia Formation or Unit) is still a hot point of discussion. A debated question is also the age of the metavolcanics interbedded in these rocks. In order to provide a clear answer to this problem, in this paper, we provide new U–Pb zircon dating and a petrographic–geochemical comparison of metavolcanics interbedded within the Bithia Formation with similar Sardinian Ordovician calc‐alkaline rocks. The Bithia metavolcanics plot in the rhyodacite/rhyolite field. They show negative troughs for Nb and Ta, negative anomalies for Sr, P, and Ti, and positive peaks for Cs, Rb, K, Th, U, and Pb in the multielement diagram normalized to primitive mantle and significant LREE enrichment, marked negative Eu anomaly, and flat HREE patterns in the chondrite‐normalized REE diagram. Owing to these geochemical features, the Bithia metavolcanics plot in the volcanic arc and active continental margin fields closely resembling Middle‐Late Ordovician felsic metavolcanics from the Sarrabus, Gerrei, Goceano, and Mt. Grighini units. A new U–Pb zircon age of 462.1 ± 4.3 Ma yielded by a metavolcanic layer within the Bithia Formation at Capo Malfatano must be interpreted as the emplacement age. The CL and BSE images of zircon grains do not show any evidence of interaction with late hydrothermal fluids that could have caused Pb loss and rejuvenated ages, confirming the Middle‐Late Ordovician age of the metavolcanics.

Minimum detection limits and applications of proton and helium induced X-ray emission using transition-edge sensor array

We have determined minimum detection limits, MDLs, for elements 14⩽Z⩽86 using a transition-edge sensor array, TES array, and as a comparison using an Amptek X-123SDD silicon drift detector, SDD. This was done using a 3MeV proton beam and a 5.1MeV helium beam. MDLs were determined for a thin film sample on top of C substrate, and for a bulk sample containing mostly Al. Due to the higher peak-to-background ratio, lower detection limits were obtainable using the TES array for most of the elements. However, for elements 30⩽Z⩽45 the performance of the TES array was not as good as the SDD performance. This is due to the limitations of the TES used at energies >10keV. The greatest advantage of TES comes, however, when detecting low intensity peaks close to high intensity peaks. Such a case was demonstrated by measuring a fly ash with overlapping Ti, V, Ba, and Ce peaks, where minimum detection limits of V, Ba, and Ce were decreased by factor of 620, 400, and 680, respectively, compared to the SDD.

Microstructural features and local properties evolution in a heavy plastic deformed Ti-29Nb-9Ta-10Zr (wt%) alloy

The microstructure, crystallographic texture and local properties evolution were investigated during thermo-mechanical processing of Ti-29Nb-9Ta-10Zr (wt%) alloy. The Ti-29Nb-9Ta-10Zr (wt%) alloy was cold-rolled by Multi-Pass Rolling (MPR) to evaluate the influence of a high intensity plastic deformation on some microstructural features (constituent phases, constitutive phase morphology, crystallographic texture) and local mechanical properties. MPR processing led to obtaining of three structural states, corresponding to a deformation degree of 60%, 80% and 90%. The microstructural features were investigated by XRD and SEM techniques while the mechanical local properties were evaluated by nano-indentation. Investigations have shown that the initial microstructure consists in a mixture of parent equiaxed polyhedral β-Ti phase grains and sub-micron α″-Ti phase dispersed inside β-Ti grains. Further, with progress of MPR processing the broad β-Ti peaks indicates heavily distorted UFC/NC β-Ti grains; also, the large and intense α″-Ti peaks suggest the presence of NC grains and a relatively high volume fraction of α″-Ti phase in the β-Ti matrix. MPR processing leads to development of a specific crystallographic texture; the most intense fibres were: γ-fibre, with two major components: {111}<110> and {111}<112>, α-fibre and ε-fibre. Also, from nano-indentation testing it was showed that local mechanical properties, such as instrumented elastic modulus (EIT), instrumented hardness (HIT) and Vickers microhardness (HV), are decreasing with progress of MPR processing due to increased α″-Ti phase fraction.

Interfacial stress evolution simulation on the graphite substrate/interlayer/diamond film during the cooling process

The addition of titanium (Ti) interlayer was verified to reduce the residual stress of diamond films. The evolution of interfacial stress during the cooling process is critical for the fabrication of large-area crack-free diamond films, so it is very worthy of further study. Variable-temperature X-ray diffraction (XRD) tests and finite element simulation were performed to evaluate the stress evolution of a diamond film. The film (with diameter of 150mm) was prepared on a graphite substrate with Ti interlayer using DC arc plasma jet. Residual compressive stress in the diamond film is gradually increased during the cooling process. Moreover, the value and growth rate of the residual stress from the XRD tests are significantly lower than the finite element simulation results. All XRD peaks of diamond, graphite, and titanium carbide (TiC) generated on both sides of the Ti interlayer shift to a larger angle. By contrast, several XRD peaks of Ti deviate to a low angle. Elastic deformation of the Ti layer may offset the lattice contraction caused by the cooling effect. Elasticity modulus of TiC is significantly greater than that of Ti, which is more inclined to release the stress of the diamond film by self-fracturing. After the variable-temperature tests, residual compressive stress of the diamond film at room temperature is 1.1GPa, whereas that before the tests is 1.4GPa. These values are significantly lower than the finite element simulation results (3.05GPa).

Fabrication of hydroxyapatite thin films on polyetheretherketone substrates using a sputtering technique

Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. A thin titanium (Ti) intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film to the PEEK substrate. The coated films were recrystallized using a hydrothermal treatment to reduce the dissolution of the HA film. The films were then characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and a UV-Vis spectrophotometer. A pull-out test was performed to measure the film-to-substrate adhesion strength, and an immersion test was performed in ultra-pure water.In the XRD patterns of the sputtered film with the Ti intermediate layer on the PEEK substrate, small HA peaks and large Ti peaks were observed. After the hydrothermal treatment, the intensity of the HA peaks increased. The transmittance of the HA films with 5 and 10nm Ti intermediate layers was >79% and 68%, respectively, in the visible light wavelength region (400–700nm) after the hydrothermal treatment. The adhesion strength of the hydrothermally treated HA films increased with decreasing thickness of the Ti intermediate layer, and the strength reached 2.7MPa with the 5-nm-thick Ti intermediate layer. In the immersion test, the HA film with a 5-nm-thick Ti intermediate layer without hydrothermal treatment exhibited a released Ti concentration of 42.0±2.4ppb. After hydrothermal treatment, the released Ti concentration decreased to 17.3±1.1ppb.

Development of Nitrogen-Doped Titanium Oxide Electrocatalysts for PEFCs

With their efficiency, high power density, and low/zero emissions, polymer electrolyte fuel cells (PEFCs) are recognized as promising energy converting system. However, high cost and insufficient durability currently hinder their commercialization. Especially, one of the major barriers is the high cost and low stability of platinum (Pt)-based catalysts 1). Thus, developing alternative catalysts with low cost and high stability has been strongly required for the commercialization of PEFCs. In the effort to reduce the cost of PEFCs, we have been developing nitrogen doped titanium oxide (N- TiO2) as a non-noble metal electrocatalyst in NEDO (New Energy and Industrial Technology Development Organization, Japan) project. In this paper, we introduce a new and convenient synthesis method of N-doped TiO2electrocatalysts and their catalytic activities for oxygen reduction reaction (ORR). In this study, we used phthalocyanine (Pc) as nitrogen source in order to dope nitrogen into TiO2. For the high surface area of electrocatalyst, TiO2 nanoparticles were deposited on high surface area carbon supports (C). The carbon supported TiO2 (TiO2/C) and phthalocyanine (Pc) were mixed and heat-treated at 900oC in inert gas atmosphere containing a small amount of hydrogen (H2) and oxygen (O2) in order to finally obtain N-TiO2/C electrocatalysts. TiO2 nanoparticles of ca. 20 nm size deposited on the carbon supports were observed by transmission electron microscope (TEM), indicating that the synthesized N-TiO2/C may have considerably high surface areas. In X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) studies, it was found that the XPS core-level peaks of Ti was very similar to that of Ti-N binding energy and the XRD peak of TiO2 shifted to higher angles, respectively. These results well explain that the nitrogen was successfully doped into TiO2 nanoparticles by our synthesis process. Fig. 1 compares the ORR catalytic activities of the synthesized N-TiO2/C and TiO2/C. The synthesized N-TiO2/C electrocatalyst shows significantly higher ORR catalytic activity than that of TiO2/C. It is believed that the enhanced catalytic activity of N-TiO2/C is due to the doping effect of nitrogen into TiO2. Acknowledgements The authors wish to thank NEDO (New Energy and Industrial Technology Development Organization) for financial support. References Ken-ichiro Ota, Yoshiro Ohgi, Kyung-Don Nam, Koichi Matsuzawa, Shigenori Mitsushima, Akimitsu Ishihara, J. Power. Sources., 196, 5256, ( 2011). Figure 1

Abstract 1346: Magnetoelectric particles cross blood brain barrier to deliver anti-tumor peptide to glioblastoma cells with on-demand release

Abstract Background: Despite significant progress in targeted drug delivery, glioblastoma is one of the least treatable tumors today. Delivering therapy across the blood-brain barrier (BBB) and overcoming resistance of tumor cells to current treatments remains a formidable task. The objective of the current in vitro and in vivo study was to show how a new class of multifunctional nanoparticles termed magnetoelectric nanoparticles (MENs) are used to achieve high-efficacy delivery of a therapeutic load across BBB, then release the load on demand, without affecting normal cells, via application of a specially tailored command sequence of D.C. and A.C. magnetic fields. Methods: Growth hormone (GH)-releasing hormone (GHRH) antagonists, a class of anti-tumor peptides, block the release of tumorigenic insulin-like growth factors. Glioblastoma cell line U87 MG were treated with 1 μM of GHRH antagonist MIA-690 bound to GMO-MENs in MEM media supplemented with 5% FBS and 1% penstrep. In parallel, an in vitro BBB experiment, designed using transwells, applied a D.C. magnetic field gradient to determine optimal field and exposure time for MENs to penetrate the BBB. Next, experimental cells were placed on a D.C. magnetic field (100 Oe) for 12 h to induce nanoelectroporation, then an A.C. field (∼50 Hz) for 2 h to release the peptide intracellularly. Control cells were treated with MIA-690 peptide only, GMO-MENs only, and MIA-690 bound to GMO-MENs at varying magnetic fields and exposure times. Cells were incubated at 37°C with 5% CO2 in a humidified atmosphere. At 24 h and 48 h post-treatment, trypan-blue vital stain assessed cell growth inhibition. Cells were then washed and lysed to measure the concentration of MENs, and MIA-690 using ICP-MS and spectrophotometry, respectively. AFM and SEM-EDS imaged MENs in cell lysate and brain tissue from mice IV injected with MENs, to find signature peaks of Ba and Ti representing the outer core of MENs, to ascertain if particles cross the BBB in vivo. Summary of data: Glioblastoma cells treated with MIA-690 bound to GMO-MENs on a D.C. magnetic field for 12 h, then an A.C. field for 2 h exhibited the greatest penetration of MENs and inhibition of tumor growth. AFM and SEM-EDS imaging showed MENs in cell lysate treated with D.C. for 12 h, but not 2 h or with no magnetic field, confirming application of a low D.C. field for 12 h triggers MENs’ penetration. On-demand MIA-690 intracellular release was highest after exposure to 12 h of D.C. field, then A.C. field at 50 Hz. Confocal microscopy confirmed a transfer of at least 50% of drug-loaded MENs across in vitro BBB, requiring 200 Oe/cm for 5 h. SEM-EDS images of brain slices taken from mice treated with MENs confirmed the presence of Ba and Ti, indicating MENs are able to cross BBB in vivo. Conclusion: Functionalized MENs are effective in treating glioblastomas using targeted, on-demand release of anti-tumor drug with the ability to cross the BBB. Citation Format: Tiffanie Stewart, Emmanuel Stimphil, Rakesh Guduru, Alexandra Rodzinski, Ping Liang, Carolyn Runowicz, Ren-Zhi Cai, Luis Salgueiro, Andrew Schally, Sakhrat Khizroev. Magnetoelectric particles cross blood brain barrier to deliver anti-tumor peptide to glioblastoma cells with on-demand release. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1346.

Ti/β-PbO2 versus Ti/Pt/β-PbO2: Influence of the platinum interlayer on the electrodegradation of tetracyclines

ABSTRACTThe behaviors of the electrodes Ti/PbO2 and Ti/Pt/PbO2 as anodes in the electro-oxidation of two antibiotics—tetracycline and oxytetracycline—were evaluated at different applied current densities, to evaluate the influence of the Pt interlayer. In the preparation of the electrodes, the electrodeposited β-PbO2 phase was homogeneous; no Ti or Pt peaks were detected in the diffractograms. The β-PbO2 surface presented significant roughness when deposited over the Pt interlayer, which also conferred significant conductivity to the material. In the electro-oxidation assays, the COD, TOC and absorbance removals increased with the current density due to an increase in the concentration of hydroxyl radicals, for both electrode materials and antibiotics tested. Slightly better results were obtained with Ti/PbO2. The primary differences observed in the antibiotics concentration decay consisted of zero-order kinetics at the Ti/Pt/PbO2 anode and first-order kinetics at the Ti/PbO2 anode with a higher oxytetracycline concentration decay than the tetracycline concentration decay. A greater amount of total nitrogen was eliminated with the Ti/PbO2 electrode. At the Ti/Pt/PbO2 anode, the organic nitrogen primarily transformed into NH4+ and the total nitrogen remained unchanged. The specific energy consumption with the Ti/Pt/PbO2 anode was significantly lower than the specific energy consumption with the Ti/PbO2 anode due to the higher electrical conductivity of the Ti/Pt/PbO2 anode. Both anode materials were also utilized in the electro-oxidation of a leachate sample collected at sanitary landfill and spiked with tetracycline, and the complete elimination of the antibiotic molecule was observed.

Preparation of Pt/Ti Electrodes Preferred Growth along the [111] Direction and Its Electrocatalytic Activity for Chlorine Evolution

To solve the short service life of dimensionally stable anode (DSA) and the high dosage of Pt electrode in the process of low concentration sodium chloride electrolysis, the Pt/Ti electrode preferred growth along the [111] direction was prepared by magnetron sputtering. The electrode surface of the magnetron sputtering Pt was uniform with particle size of 10 nm. The characteristic peaks of Ti were not found in the XPS spectrum, which showed that the Ti matrix was completely covered by Pt. Electrochemical cyclic voltammetry (CV) results showed that the electrochemical area of the magnetron sputtering Pt was the smallest (1.08 cm), which was close to the apparent surface area of the electrode. In addition, the electrical amperage ratio of the oxygen adsorption area to the hydrogen adsorption area was only 0.83 calculated from the CV diagram. So it can be predicted that the oxygen adsorption capacity on the magnetron sputtering Pt is very poor and not prone to the oxygen evolution reaction. When the electrode potential was 1.6 V, the chlorine evolution reaction current of the magnetron sputtering Pt was 0.085 A/cm in the unit electrochemical area, which was 3.27 and 49.0 times that of the electro-deposition Pt and thermal decomposition Pt, respectively. It showed that the magnetron sputtering Pt had a high activity of chlorine evolution in the unite active site. It may be related to the special morphology of its surface (111) crystal surface. On the basis of the 第 5期 朱玉婵, 等: 沿[111]方向择优生长 Pt/Ti电极制备及析氯电催化活性 511 above, the Tafel slope of the magnetron sputtering Pt was 44.3 mV/dec. The mechanism of chlorine evolution reaction was in accordance with the mechanism of Volmer-Heyrovsky, and the rate controlling step was the electrochemical desorption step.

Ion-induced changes in the structure and phase composition of nanocrystalline TiZrSiN coatings formed via magnetron sputtering

The influence of ion irradiation (180-keV Xe2+ and doses of 1 × 1016 and 5 × 1016 cm–2) on the structure and phase composition of thin (300 nm) nanocrystalline (Ti,Zr)1–xSixNy films deposited via reactive magnetron sputtering (Si content x ≤ 0.22) is investigated. It is found that an increase in the Si concentration of the coating stimulates successive structure conversions from nanocrystalline (x < 0.07; grain size is about 18 nm) to nanocomposite (0.07 ≤ x ≤ 0.11; grain size is about 8 nm) and amorphous (x ≥ 0.18) states. The phase composition of the coatings varies from diphase (c-(Ti,Zr)N + a-TiSiNx) to amorphous (a-TiZrSiN). The nanocomposite coating consists of c-(Ti,Zr)N solid-solution grains (their size is ~8 nm) surrounded by an amorphous a-TiSiN matrix. Ion irradiation exerts no influence on the structural-phase state of the nanocrystalline and amorphous films. The diffraction peaks of the (Ti,Zr)N solid solution is revealed to be split because a double-layer structure is formed. This is associated with Xe-ion implantation into the coating. (Ti,Zr)N solid-solution grains are found to crystallize if amorphous coatings (0.18 ≤–≤ 0.22) are irradiated with xenon ions.