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1.
The research of the effects of surfactants on coloring reaction between titanium and phenyl fluorone was developed.A survey of coexisting elements in the houttuynia cordata thunb was carried out by X-ray fluorescence spectrometry,and a series of interference tests and analyses were performed.The interference can be eliminated by processing through high temperature cineration and adding ascorbic acid.A new method of determination of titanium in houttuynia cordata thunb was established by phenyl fluorone spectrophotometry in the presence of Emulsifier OP.The results showed that Beer's law is obeyed within the range of 0~0.32 μg·mL-1 for titanium.The relative standard deviation(RSD) was 1.9%~2.0%,and the recovery was 96.8%~100.6%.The method was applied for determination of titanium in houttuynia cordata thunb with satisfactory results. 相似文献
2.
Quantitative ESCA has been used for studying the surface of mixed precipitates. When the precipitation is complete and homogeneous, as with titanium and zirconium hydroxides, almost complete correlation is found between the atomic ratio of the elements in the precipitate and that estimated by the Hirokawa-Ebel method, but not for incomplete mixed precipitation, as with copper and silver hydroxides. When precipitated copper and silver are reduced to the metals with iron or zinc, the surface is enriched in copper. 相似文献
3.
Ilse Papst Gerald Kothleitner Ferdinand Hofer Leo Binder 《Monatshefte für Chemie / Chemical Monthly》2001,132(4):541-549
Summary. Energy-filtering transmission electron microscopy (EFTEM) and electron energy-loss spectrometry (EELS) have been used to
measure the distribution of titanium in titanium-doped electrolytic manganese dioxide, which consists of large particle agglomerates
of some micrometer diameter. In contrast to previous investigations, where the distribution of the doping elements can only
be investigated at the thinnest regions of the agglomerates, we describe an improved procedure which allows to measure the
concentration of the dopant not only at the thinner edges of the particle agglomerate, but also in the interior. The titanium
distribution maps showed that titanium is enriched on the surface of the agglomerates and in pores penetrating into their
interior. Within the agglomerates, titanium is evenly distributed, and in manganese dioxide the titanium concentration could
be analyzed quantitatively by EELS spectrometry. Based on these results, suggestions for possible improvements of the doping
process and for the preparation of the product are given.
Received November 29, 2000. Accepted (revised) December 12, 2000 相似文献
4.
采用火花放电原子发射光谱法测定了钛及钛合金中碳、铁、铝和钒的含量。通过对钛合金样品的表面处理方式、氩气流量和压力、类型标准化等参数的摸索,确立了一套系统的分析方法。结果表明,4种元素测定的相对标准偏差在0.40%~6.8%,测定结果和化学湿法分析结果相比基本一致,比较适合批量检测。 相似文献
5.
采用火花放电原子发射光谱法测定了钛及钛合金中碳、铁、铝和钒的含量。通过对钛合金样品的表面处理方式、氩气流量和压力、类型标准化等参数的摸索,确立了一套系统的分析方法。结果表明,4种元素测定的相对标准偏差在0.40%~6.8%,测定结果和化学湿法分析结果相比基本一致,比较适合批量检测。 相似文献
6.
《Analytica chimica acta》1987,203(1):55-66
Interferences of the matrix elements of glass ceramics (Al, Mg, Na and Si) on the titanium signal obtained by atomic absorption spectrometry with a nitrous oxide/acetylene flame were studied by means of experimental design. Quadratic polynomials were chosen as the model; full factorial designs with two, three and four variables at three levels were applied. As expected, aluminium increased the titanium signal, while magnesium reduced it. All the investigated elements interfered nonadditively with the titanium signal; the standard addition method therefore does not provide accurate results. Graphic evaluation of the empirical response surfaces was used to establish optimum conditions for titanium; these surfaces were compared with the polynomial surfaces to check the models. The results obtained on interactions in the system are used with some thermodynamic data to estimate the nature of the compounds formed in the flame. The strong interferences on the titanium signal requires fairly close matrix matching between the standard and sample solutions. The proposed method allows the determination of 3–6% Ti in glass ceramics with a relative standard deviation of 1%. 相似文献
7.
M. G. Martsenyuk-Kukharuk S. N. Orlik A. P. Martsenyuk-Kukharuk 《Theoretical and Experimental Chemistry》1993,28(3):188-190
An x-ray photoelectron spectroscopic investigation of supported palladium-containing catalysts based on porous metals (titanium and stainless steel) and a block silica support with honeycomb structure containing 0.5 mass % palladium was carried out for analysis of the composition and valence state of elements in the surface layer of the catalysts. The investigations confirmed the previously proposed mechanism of poisoning of palladium catalysts by sulfur dioxide and also showed that sulfur accumulation is the reason for a decrease of the activity of palladium-containing catalysts during long-term industrial tests in cleaning of natural-gas combustion products.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 28, No. 3, pp. 232–235, May–June, 1992. 相似文献
8.
《结构化学》2020,39(4):615-622
The traditional strengthening elements of titanium alloys include Al, Mo, V, etc., however, the high cost and toxicity of these elements put a limit on their further applications for biomaterials. Ubiquitous light elements such as oxygen are hopeful replacement due to high biocompatibility. It is recognized that the oxygen enhances the strength but pays the price of brittleness, thus the amount of oxygen is constrained. However, recent study results indicated that excess oxygen can keep high ductility together with high strength of titanium. This paper reviews the influence and the mechanism of oxygen on the strength and ductility of titanium alloys, and provides a new perspective for the strengthening method of titanium alloys. 相似文献
9.
Tsodikov M. V. Slivinskii E. V. Yushchenko V. V. Kitaev L. E. Kriventsov V. V. Kochubei D. I. Teleshev A. T. 《Russian Chemical Bulletin》2000,49(12):2003-2006
The data of temperature-programmed desorption of ammonia from the surface of oxide systems and IR spectroscopy were used to demonstrate that the strength of the surface acid sites in titanium oxides prepared by the alkoxo method and modified by aluminum decreases with respect to that in nonmodified titanium oxide. Modification of titanium oxide with P3+ ions from ethriol phosphite almost completely suppresses the acid properties. Modified oxides are able to chemisorb water. XANES data suggest that modification of titanium oxide with phosphorus ions increases the electron density on the titanium atoms and, correspondingly, the basicity of the materials. 相似文献
10.
XPS study on the use of 3-aminopropyltriethoxysilane to bond chitosan to a titanium surface 总被引:4,自引:0,他引:4
Martin HJ Schulz KH Bumgardner JD Walters KB 《Langmuir : the ACS journal of surfaces and colloids》2007,23(12):6645-6651
Chitosan, a biopolymer found in the exoskeletons of shellfish, has been shown to be antibacterial, biodegradable, osteoconductive, and has the ability to promote organized bone formation. These properties make chitosan an ideal material for use as a bioactive coating on medical implant materials. In this study, coatings made from 86.4% de-acetylated chitosan were bound to implant-quality titanium. The chitosan films were bound through a three-step process that involved the deposition of 3-aminopropyltriethoxysilane (APTES) in toluene, followed by a reaction between the amine end of APTES with gluteraldehyde, and finally, a reaction between the aldehyde end of gluteraldehyde and chitosan. Two different metal treatments were examined to determine if major differences in the ability to bind chitosan could be seen. X-ray photoelectron spectroscopy (XPS) was used to examine the surface of the titanium metal and to study the individual reaction steps. The changes to the titanium surface were consistent with the anticipated reaction steps, with significant changes in the amounts of nitrogen, silicon, and titanium that were present. It was demonstrated that more APTES was bound to the piranha-treated titanium surface as compared to the passivated titanium surface, based on the amounts of titanium, carbon, nitrogen, and silicon that were present. The metal treatments did not affect the chemistry of the chitosan films. Using toluene to bond APTES on titanium surfaces, rather than aqueous solutions, prevented the formation of unwanted polysiloxanes and increased the amount of silane on the surface for forming bonds to the chitosan films. Qualitatively, the films were more strongly attached to the titanium surfaces after using toluene, which could withstand the ultrahigh vacuum environment of XPS, as compared to the aqueous solutions, which were removed from the titanium surface when exposed to the ultrahigh vacuum environment of XPS. 相似文献
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12.
以二氧化钛膜为载体,配制一定浓度的AgNO3溶液,利用光析出方式在氧化钛膜表面还原析出Ag,控制光析出时间来控制氧化钛膜表面上的银析出量,制备银负载氧化钛膜,研究膜的抗菌特性和光催化特性.结果表明:由于银在氧化钛膜上的负载,使膜的抗菌性能得到很大的提高,在保持氧化钛膜的光催化能力基本维持不变的前提下,由于在氧化钛膜的表面负载银,对E.coli和青霉菌的杀菌能力分别提高了104和102,光催化降解甲基橙的能力与氧化钛膜相比,能够提高10%左右,显示了良好的光化学特性. 相似文献
13.
M. M. Mikhailov S. A. Yuryev G. E. Remnev R. V. Sazonov V. A. Vlasov G. E. Kholodnaya 《Journal of Thermal Analysis and Calorimetry》2017,130(2):671-680
We have investigated the processes occurring within titanium dioxide powders heated and modified by silicon dioxide nanoparticles at 150, 400, and 800 °C. It has been figured out that the mentioned modification stipulates the increase in the powders’ radiation resistance. While investigating, we employed methods of the near-/mid-infrared regions spectrophotometry, derivatography, and mass spectrometry. The research results show that the increase in the radiation resistance at the heating is stipulated by a number of factors, namely (1) the desorption of the physically/chemically bound gases, (2) upfilling of the released bonds with the oxygen molecules, and (3) the improvement of titanium dioxide stoichiometry on the surface. The after-modification radiation resistance increases excessively (as opposed to the heating) due to the fact that the electron–hole pairs relaxate on the nanoparticles, which precipitate onto the surface of titanium dioxide powder. 相似文献
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16.
Ikeyama M Nakao S Morikawa H Yokogawa Y Wielunski LS Clissold RA Bell T 《Colloids and surfaces. B, Biointerfaces》2000,19(3):263-268
Titanium or titanium alloys are very attractive biomedical materials. Biocompatible elements of oxygen, calcium and phosphorus were implanted into titanium and changes of surface hardness were measured using an ultra micro indenter (UMIS-2000). A multiple load-partial unload procedure that can reveal a hardness versus depth profile was adopted. Depth profiles of concentration of implanted ions were obtained by SIMS measurement. For O and P implantation, it is observed that the hardness increases with the increases in the dose. O implantation produced the largest increase in hardness, up to 2.2 times higher than the unimplanted titanium. On the other hand, Ca implantation produced only a small increase in the hardness that was independent of the ion dose. The surface oxide layer of a Ca implanted titanium sample was much thicker than the unimplanted samples or those implanted with O and P ions. The depth of maximum hardness increases with increasing energy of implanted ions. The depths of the maximum hardness occur at indentation depths of one-third to one-eighth of the mean ranges of implanted ions. 相似文献
17.
DFT calculations of the oxyethylation pathways of monoethylene glycol (MEG) and diethylene glycol (DEG) were performed on a model fragment of phosphorus-doped titanium dioxide (anatase). It was shown that the surface hydroxyl group of titanium dioxide, whose proton initiates C-O bond cleavage in the ethylene oxide molecule, plays the key role in the activation of the molecule. At the same time, the phosphoryl group -P(OH)2O activates the reactant molecule R (MEG, DEG, etc.) and carries out the synchronous proton transfer from R to the hydroxyl oxygen atom of titanium dioxide, thus restoring the catalyst structure and closing the catalytic cycle. This restructuring occurs synchronously in one step. The substitution of the catalyst hydroxyl groups by alkoxyl groups can influence oxyethylation occurring via the bimolecular nucleophilic substitution mechanism and can poison the catalyst in some cases. 相似文献
18.
V. A. Zazhigalov A. I. Kharlamov L. Depero A. Marino I. V. Bacherikova S. V. Khalameida J. Stoch 《Theoretical and Experimental Chemistry》2000,36(2):98-102
The mechanochemical modification of a V−Ti−O composition in ethanol and water was carried out in a planetary mill. X-ray phase
analysis was used to show that the X-ray diffraction patterns of the modified samples result from overlapping of the patterns
of the individual oxides, while the modification conditions affect the relative intensity of the reflections. The micro-Raman
spectra indicated that homogeneity of this composition is achieved after only 30 min treatment in water and 20 min treatment
in ethanol. X-ray photoelectron spectroscopy showed that the medium and duration of the treatment do not affect the valence
state of the elements but do significantly alter the ratio of the elements in the surface layer. Mechanochemical treatment
of mixtures of vanadium and titanium oxides permits enhancement of the activity and selectivity of the V−Ti−O compositions
in the oxidation of n-pentane and o-xylene.
Translated from Teoreticheskaya i éksperimental'naya Khimia, Vol. 36, No. 2, pp. 105–110, March–April, 2000. 相似文献
19.
Yada M Inoue Y Uota M Torikai T Watari T Noda I Hotokebuchi T 《Langmuir : the ACS journal of surfaces and colloids》2007,23(5):2815-2823
Sodium titanate nanotube/titanium metal composites were synthesized by hydrothermal treatment of titanium metals with various morphologies such as plate, wire, mesh, microsphere, and microtube at 160 degrees C in aqueous NaOH solution and by the subsequent fixation treatment by calcination at 300 degrees C. The surface of the composite was covered with sodium titanate nanotubes with a diameter of approximately 7 nm, and the core part of the composite was titanium metal phase. The raw titanium metal acts as a template or a morphology-directing agent of micrometer size or more to arrange the nanotubes as well as a titanium source for the formation of nanotubes. The concentration of titanium species increases in the reaction solution as the dissolution of titanium metal is accelerated by the reaction between titanium and OH-. Furthermore, with an increase in concentration of titanium species in the reaction solution, the titanium species are re-precipitated as sodium titanate nanotubes onto the titanium metal. Titanium metal with a large surface area and volume can form sodium titanate nanotubes on the surface of the titanium metal, though titanium metal with a small volume and surface area tends to dissolve with the hydrothermal treatment. Even in the synthesis using titanium metal with a small volume and surface area, sodium titanate nanotubes are formed and cover the surface of the titanium metal by adding another titanium metal as a source of titanium species in the reaction solution. 相似文献
20.
Muhammad Zakir B.D.S MSc PhD Taina Laiho Sari Granroth Edwin Kukk Chun Hung Chu James Kit-Hon Tsoi Jukka Pekka Matinlinna 《Surface and interface analysis : SIA》2022,54(7):747-758
This laboratory study aimed to compare, contrast, and evaluate the effect of a novel dual surface modification method on the adhesion strength of resin composite cement to titanium. C.p.-2 grade titanium samples were silica-coated, etched with HNO3(69vol %) or a blend of HCl (35vol %) and H3PO4 (85vol %), for 1 h at 80°C. Surface roughness was measured by surface roughness profilometry, topographic analysis by scanning electron microscopy (SEM), atomic force microscopy (AFM), and surface analyses by energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS). Silanization of all specimens was carried out after SEM, EDX, and AFM analysis, before enclosed mold microshear bond strength testing (EM-μSBS). Adhesion strengths were measured after artificial ageing: 1 day, 1 week, 4 weeks, and 8 weeks by EM-μSBS testing and failure mode analysis by optical microscopy. Polished titanium was used as a control. The highest surface roughness was observed in titanium samples treated with silica-coating + HCl-H3PO4 etching. The elemental composition confirmed the presence of Ti, O, C, with Si and Al in samples treated with silica-coating. A gradual decrease in EM-μSBS values was observed in all titanium samples with adhesive and cohesive failure modes. The novel dual surface modification method applied in this study suggests that silica-coating + HCl-H3PO4etching strongly affects titanium surface topography and roughness. The presence of Si on silica-coated surface modified titanium before silanization with an experimental silane has a positive effect on the EM-μSBS of titanium samples treated with silica-coating only or silica-coating + HNO3 etching. 相似文献