Titanium-supported nickel-copper oxide catalysts for oxidation of carbon(II) oxide

Nickel-copper compositions for catalytic oxidation of carbon(II) oxide to carbon(IV) oxide were prepared by impregnation of oxide films on titanium surface, obtained by plasma electrolytic oxidation followed by annealing. Plasma electrolysis oxide coatings with a layer thickness of 5 to 50 μm were generated using different electrolytes. The compositions were studied by X-ray powder diffraction, X-ray spectral analysis, and electron microscopy, and moisture absorption of the initial plasma electrolytic structures was estimated. A linear correlation was found between the overall concentration of nickel and copper (4 to 25 mol %) in the surface layer of ∼2–5-μm compositions and their catalytic activity. The overall concentration of nickel and copper was found to increase in parallel with the moisture absorption of plasma electrolytic oxidation coatings. Nickel-copper compositions based on plasma electrolytic oxidation coatings generated in a silicate electrolyte displayed the best catalytic, mechanical, and adhesion properties.     

AZ91D镁合金上钼改性锌系磷化膜的制备、 结构及性能

采用在磷化液中添加钼酸钠及腐蚀抑制剂的方法, 在AZ91D 镁合金表面上制备了均匀细致的锌系复合磷化膜. 用XRD对膜层的化学组成及结构进行了表征,用SEM和EDS对膜层的形貌和组分含量进行分析. 结果表明, 磷化膜主要由Zn3(PO4)2·4H2O和单质Zn组成. 在磷化液中加入钼酸钠使磷化膜组织更加细致而且无裂纹. 磷化液中的钼酸钠含量为1.5 g/L时, 磷化膜的结晶最致密, 单质锌的含量最高, 耐蚀性最好. 还提出了一种快速测量镁合金表面膜层耐蚀性的试验方法, 同时对镁合金上的磷化反应的机理进行了探讨.     

1. History of CA and evolution of the markets

An overlook is given of the 100 years of technical, industrial and chemical development of cellulose acetate. CA has been used as raw material in the fields of laquer, plastics, textile, Filter Tow, film, membrane and others. In the field of applications for plastics and textiles CA was quite successful for many years, but was then slowly substituted by other polymers. Total cellulose acetate demand is growing, especially for Filter Tow in cigarettes filters and film for polarisers in LCD-displays.     

Effect of molecular structure of epoxy oligomers with perfluorinated fragments on hydrophobic properties of powder coatings

An effect of the chemical structure of a series of the synthesized epoxy oligomers with perfluorinated fragments on the surface and mechanical properties of thermosetting powder coatings based on epoxy compositions was investigated. The possibility of their use as modifiers for effective hydrophobic epoxy coatings with a high level of physical and mechanical properties was demonstrated.     

Calcium and strontium phosphates coatings on titanium formed by the plasma electrolytic oxidation

Oxide-phosphate coatings were formed in electrolytes with Ca(II) and Sr(II) polyphosphate complexes. The data on an effect of a ratio of metal polyphosphate complexes in the electrolyte, treatment time on an elemental and phase compositions, thickness and morphology of coatings were obtained. The approach is promising for application of the coatings containing calcium phosphate with additives of phosphates of other metals to titanium implants.     

Epoxy-urethane binders based on the blocked isocyanate Desmocap 11

The influence of the blocked isocyanate Desmocap 11 on the physico-mechanical characteristics of compositions based on the epoxy resin DER 330 and the cycloaliphatic amine hardener Polypox 488 was studied. A series of epoxy-urethane compositions that can be used as binders for coatings, adhesives, and sealants were obtained.     

Study of cell membrane based coatings in capillary electrochromatography

Neuronal cell line based membrane models were studied as capillary coatings by capillary electrochromatography. The membrane models were based either on membrane suspensions or on membrane lipid extractions. The stability of the coatings at different pH values and buffer compositions was studied. The results showed that the cell membrane suspension based coatings were stable over pH range of 6.5–10.8. The use of Hepes instead of TE buffer did not improve the coating performance.     

A New Approach to Characterization of Barrier Properties of ORMOCER Protective Coatings

The Radiometric Emanation Method (REM) was used for the characterization of barrier properties of protective coatings. Radon diffusion parameters of the hardened protective layers prepared from ORMOCER lacquers of varying compositions were examined. The differences in the barrier properties of non weathered and weathered ORMOCER coatings, as well as of INCRALAC coatings, were compared. REM is recommended for the characterization of barrier properties of protective coatings submitted to weathering at varying conditions and time.     

Electrochemical corrosion resistance performance of sustainable resource-based nanoconducting polymer composites in alkaline medium

The corrosion resistance performance of poly (otoluidine) (POT)-dispersed castor oil-polyurethane, (COPU) nanocomposite coatings, POT/COPU, with three different compositions (i.e. 0.25, 0.5 and 1.0 wt%) in alkaline medium is studied. The coatings are applied on mild steel specimens by brushing. Corrosion resistance behaviour of these coatings is investigated using potentiodynamic polarization measurements, electrochemical impedance spectroscopy (EIS) and by weight loss. The morphological behaviour of corroded and uncorroded coated specimens is investigated by scanning electron microscopy (SEM). It is interesting to report that the presence of conducting polymer nanoparticles in POT/COPU coatings suppresses the saponification of COPU in an alkaline environment. These investigations show that the dispersion of POT in COPU remarkably improves the corrosion resistance performance of COPU in alkaline media. POT/COPU (1.0 wt%) coatings have potential as anticorrosive-coating materials in alkaline media at higher pH. These coatings have a higher resistance to alkaline medium in comparison to other compositions.     

Development of adhesive ozone-resistant compositions based on chlorosulfonated polyethylene for elastomeric materials

Chlorosulfonated polyethylene (CSPE) is modified by a Diafen FP amine-containing compound. It is shown that compositions based on modified CSPE can be used as adhesive compositions for rubber splicing and coatings for rubber protection from ozone aging.     

Role of the interaction between forming nanocrystals and glass surface on the structure and properties of ZnO-based films

The interaction between glass surface and forming nanocrystals plays the important role in the formation of thin ZnO coatings crystal structure. The comparative study of the crystal structure of thin ZnO-based films and powders having similar chemical compositions was performed with the use of SEM, XRD analysis, optical, and luminescent spectroscopy. The influence of different coatings parameters (chemical composition, thickness) on the spectroscopic and morphological properties of thin films and powders reveals the structural features of the interaction between forming ZnO nanocrystals and glass surface. ZnO–SnO₂ coatings and powders were prepared by liquid polymer-salt technique. This method provides the close contact between the coatings’ precursors with a surface of the glass during both the nucleation and the initial growth stage of forming oxide crystals. The interaction of nanocrystals and substrate surface is responsible for the texture formation in the ZnO films and determines some features of their optical properties.     

Laminated Composition Coatings

The present paper discusses the results of research into production of thermally stable composition coatings that have nanostructured inorganic non-metallic coating (NIN coating) of different compositions on zirconium alloy substrate as their part, as well as metals introduced into coating pores. Researchers identified optimal conditions of microplasma treatment, as well as composition of electrolyte solutions for each stage of composition material production. Was used to construct and analyze current-voltage characteristics obtained in the course of electrical impact upon samples. Phase and element composition of NIN coatings, surface morphology of NIN coatings and coatings with metal injected into were studied.     

Magnetic characteristics of iron-modified oxide layers on titanium

Iron-modified TiO₂ coatings on titanium exhibiting ferromagnetic properties are formed by combining plasma electrolytic oxidation (PEO) and impregnation with subsequent annealing. It is found that iron is contained in the composition of dispersed particles with sizes of 1–10 μm distributed over the surface of the coatings. It is shown that the coercive force of the coating on titanium samples is 20–70 Oe. The composition, structure, and magnetic properties of the samples with coatings prepared via direct PEO and by combining PEO and impregnation are compared. It is concluded that impregnation and annealing procedures can be used to impart ferromagnetic properties to PEO coatings with different compositions, e.g., protective coatings and coatings applied in catalysis or medicine.     

Use of Sodium Borohydride in Electrodeposition of Nickel-Boron Coatings

Russian Journal of Applied Chemistry - Possibility was found of using the sodium borohydride additive in technologies for electrodeposition of nickel-boron coatings with various compositions and...     

Erosion-resistant metal nitride coatings and carbide and their plasmochemical synthesis

The influence of ion-plasma coatings made from high-hardness metal compounds on the erosion and corrosion resistance and mechanical properties of the alloy (substrate) + coating system is studied. The influence of the thickness, composition, and design of coatings based on metal nitrides and carbides on the relative gas-abrasive wear resistance of alloy+coating compositions in a gas-abrasive flux of quartz sand is discussed. It is shown that the zirconium nitride coating provides the best protection for compressor blades made of titanium alloys, without any decrease in fatigue resistance of the alloys, and chromium carbide coating is the most appropriate protection for steel compressor blades.     

Phase-separation and distribution of phenyl groups for PhTES-TEOS coatings prepared on polycarbonate substrate

Phenyltriethoxysilane (PhTES) and tetraethoxysilane (TEOS) coatings [xPhTES·(100 − x)TEOS (mol%)] (x = 0 − 80) were prepared on polycarbonate (PC) substrate, and adhesion, surface hardness and distribution of phenyl groups were studied. The coatings with more than 60 mol% of PhTES showed good adhesion (≈ 100%), and the pencil hardness of PC substrate (4B) improved to 2B or B after the coatings. Bulk gels with the same compositions were also prepared, and distribution of phenyl groups were estimated using fourier transform infrared (FT-IR) spectroscopy (KBr method for bulk gels and attenuated total reflection (ATR) method for coatings). A significant difference for the distribution of phenyl groups was clearly observed between bulk gels and coatings, suggesting PC substrate affects the distribution of phenyl groups in coatings. The adhesion and FTIR results revealed that there is an interaction caused by π-electrons between benzene rings on PC substrate and phenyl groups of PhTES-TEOS coatings. It was found that the adhesion was strongly correlated with the phenylsilsesquioxane networks formed around PC substrate side.     

Modeling of the solution composition and a study of the electrodeposition of the Cu-Zn alloy

Choice of ligands in development of new solution compositions for electrodeposition of alloys was simulated and the possibility of electrodeposition of the Cu-Zn alloy from a solution of gluconate complexes of ions of these metals was experimentally verified. The effect of various factors on the admissible current density of electrodeposition of high-quality Cu-Zn alloy coatings, brass composition, current efficiency by the alloy, and strength of brass adhesion to rubber was studied.     

Preparation of cationic latices comprising hollow thermostable particles

A method is described for the preparation of cationic latices comprising submicron hollow particles for a possible application as a thermally stable polymeric pigment in coatings or pigmented compositions on the basis of thermosetting polymers cured at temperatures up to 170–190 °C. The method is based on the deposition of melamine–formaldehyde resin in the form of cationic colloid onto anionic hollow particles resulting in the recharging of anionic hollow particles and the formation of an outer melamine shell, which provides thermal stability of the hollow particles at curing and application of pigmented coatings and compositions. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2225–2234, 2004     

The migration of styrene butadiene latex during the drying of coating suspensions: when and how does migration of colloidal particles occur?

Surface elemental compositions of model latex clay coatings on an impervious substrate consolidated under various conditions were measured using the XPS technique, in order to clarify when and how colloidal latex particles migrate to the surface during drying. Under similar drying conditions, surface carbon content decreased with the addition of a water-soluble polymer to the coating colors, while remaining virtually unchanged for coatings of different coat weights made with a given color, indicating that surface carbon content variation is mainly caused by migration of latex rather than of water-soluble polymer. The results also showed that for coatings made with a given suspension, surface carbon content decreased with increasing delay time between coating and heating. For coatings frozen during consolidation and dried by sublimation, surface carbon content increased with increasing drying time before freezing. These results suggest that for the model coatings studied, latex migration mainly occurs after coating application before capillary formation during the initial drying stage when coatings are in the liquid phase, contradicting both the conventional capillary transport and boundary wall migration mechanisms. An alternative mechanism which attributes latex migration to surface trapping effect and to higher Brownian mobility of the smaller latex particles compared with pigment appears to provide a systematically consistent explanation to those phenomena. The new particle migration mechanism implies that segregation of colloidal particles is a ubiquitous phenomenon that would occur not only during the drying of paper coatings but also during consolidation of colloidal films containing particles of different sizes. This is of great importance in the control of surface compositions of nanocomposite coatings.     

物理蒸镀Ni-Al镀膜与高速融射MCrAlY涂层之抗热循环氧化性比较

本研究乃以阴极电弧放电离子被覆技术在Inconel 6 0 0超合金上被覆Ni_Al镀层 ,与目前常用的高速融射CoCrAlY涂层同时进行 1 1 0 0℃高温循环氧化试验 ,比较二者的抗高温循环氧化性 .研究结果显示 :使用Ni52 Al4 8,Ni6 0 Al4 0 及Ni70 Al30 3种靶材分别得到富铝成份的Ni35Al6 5,Ni4 0 _Al6 0 以及Ni53Al4 7的镀膜 .在 1 1 0 0℃热循环氧化测试下 ,由于富铝的Ni_Al镀膜表面能快速生成Al2 O3层以阻止内部持续氧化 ,因而有较CoCrAlY涂层为低的氧化重量增加率