TiO2 photocatalysts promoted by alkali metals

The new photocatalysts have been obtained by calcination titanium dioxide of anatase type (Tytanpol A11, “Police” Chemical Factory, Poland) with hydroxides (Li, Na, K, Ba) and carbonate (Sr). The obtained materials have been characterised by several analytical methods, like XRD, FT-IR/DRS, DR–UV–vis. The photocatalytic oxidation of phenol as model contamination has been investigated over obtained alkali metals–TiO₂. From all investigated photocatalysts only materials based on titanates in perovskite forms (BaTiO₃, SrTiO₃) have higher activity than pure titanium dioxide A11.     

Fabrication of Bioactive Material-Reinforced Caprolactam-Based Cyanate Ester Composite for Coating Applications

The nanocomposite material consisting of bioactive amine-terminated cyclotriphosphazene and functionalized titanium dioxide nanoparticle-reinforced caprolactam-based cyanate ester composites (amine-terminated cyclotriphosphazene/functionalized titanium dioxide/cyanate ester–caprolactam) was developed for coating applications. The structural characterization and coating properties of amine-terminated cyclotriphosphazene/functionalized titanium dioxide/cyanate ester–caprolactam composites coated on MS plates were studied by Fourier transform infrared spectroscopy, scanning electron microscope, contact angle, and electrochemical measurements. The antibacterial studies of amine-terminated cyclotriphosphazene/functionalized titanium dioxide/cyanate ester–caprolactam were also performed by disk diffusion method. Hence, the results conclude that the amine-terminated cyclotriphosphazene/functionalized titanium dioxide/cyanate ester–caprolactam nanocomposites have improved hydrophobic, thermal properties, enhanced antimicrobial, and corrosion resistance properties due to the incorporation of amine-terminated cyclotriphosphazene and functionalized titanium dioxide nanoparticles.     

Sol–gel synthesis highly porous titanium dioxide microspheres with cellulose nanofibrils-based aerogel templates

Highly porous titanium dioxide microspheres had been prepared via a template-assisted sol–gel process with cellulose nanofibril aerogel microsphere template. The modified porous titanium dioxide microspheres showed a typical super-hydrophobic property. The method reported in this study may be applied to fabricate other inorganic materials with desired porous structure.     

Synthesis and characterization of local clay–titanium dioxide core–shell extender pigments

A simple chemical technique has been used to prepare core–shell extender pigments based on Nigerian indigenous clays as core and titanium dioxide as shell. The prepared core–shell extender pigments were characterized using X-ray fluorescence and scanning electron microscopy. The physico-chemical properties of these extender pigments were also evaluated according to ASTM measurements. The study showed that the prepared core–shell pigments were nontoxic and environmentally friendly. They are of low cost and can be incorporated in semi-gloss paints, paper, rubber, and plastic composites without much effect on the volume. The characteristics of these pigments showed that they combine the properties of both their precursors, and have the potential to overcome their disadvantages, e.g., low hiding power of clays and photochemical activity of titanium dioxide.     

Surface modification on nanoscale titanium dioxide by radiation: Preparation and characterization

Electron beam mutual radiation to induce graft polymerization has been carried out respectively, between nanoscale anatase‐ or rutile‐titanium dioxide particles surface and methyl methacrylate (MMA). The composition and properties of surface modified titanium dioxide were investigated by a number of surface sensitive techniques: X‐ray photoelectron spectrum (XPS), FTIR, X‐ray diffraction (XRD), and NMR. Results of the technological measurements show how surface chemistry is affected throughout the surface modification process, finally leading to a complete and homogeneous vinyl compound overlayer on top of the titanium dioxide samples. In comparison with stereochemical structures of the graft molecular chains and the PMMA induced by radiation polymerization, the surfaces of the oxides are considered to provide a template for the graft polymerization. The grafted titanium dioxide is found to produce a stable colloidal dispersion, in good solvents for the grafted polymer, and the dispersibility of grafted dioxides is influenced by temperature. In addition, the wettability of the surface of titanium dioxide to water is readily controlled by grafting of hydrophilic or hydrophobic polymers. Based on the above results, it is concluded that MMA is covalently linked to the surface of titanium dioxide by a surface modification process. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci, 100: 3510–3518, 2006     

Determination of the kinetic pathway in the electrochemical reduction of titanium dioxide in molten calcium chloride

An investigation into the kinetics of the electrochemical reduction of titanium dioxide (TiO₂) to titanium metal (Ti) in molten calcium chloride has been performed. Partially reduced samples were prepared by terminating the reduction process after different reaction times and characterised by means of X-ray diffraction analysis. Based on the time-dependent changes of phase composition as well as thermodynamic and kinetic considerations, the reaction path has been derived. The key result is that the reduction proceeds through a number of individual stages some of which involve the formation and decomposition of calcium titanates. Several of the partially reduced samples were examined further through scanning electron microscopy and energy-dispersive X-ray analysis. The results demonstrate that the electrochemical reduction of titanium dioxide to titanium metal is accompanied by substantial changes in the microstructure.     

二氧化钛功能薄膜研究发展与应用

二氧化钛薄膜在紫外光照射下的光催化活性和亲水性吸引了许多科学工作者对其进行了大量的研究．本文对近年来二氧化钛功能薄膜的研究发展与应用作了简要介绍，同时也对研究中存在的问题和将来研究发展的方向进行了简单评述.     

新型环氧防腐涂料的研究

采用在环氧树脂中加入纳米复合铁钛粉防锈颜料WD—D-325、固化剂、制备了新型环氧树脂防腐涂料。由于纳米技术的特性，该防腐涂料具有较高的防腐性、优异的附着力和柔韧性。实验确定了复合铁钛粉防锈颜料在环氧防腐涂料中的添加量。作为新型的环保颜料，复合铁钛粉防锈颜料可以替代红丹、锌铬黄等颜料。     

Photocatalytic properties of silicone polyesters using calcium phosphate/titanium dioxide

This study uses titanium dioxide treated with calcium phosphate to prepare multilayer structure composites. These products are regarded as photocatalysts. Utilizing polyethylene glycol (PEG)–silicone polyester as an adhesive spread on matrix surfaces, this can provide these products with antifouling properties, good weather resistance, and antibacterial property. It has been observed that UV irradiation has caused changes in the film molecular structure of PEG–silicone polyesters, as well as changes in the surface morphology. These changes in molecular structure have been observed by FTIR and Raman analysis. PEG–silicone polyesters contain silicon atoms with both organic and inorganic characteristics. This makes fixation of photocatalysts possible and retards oxidation of organic materials in the polyesters. The results of FTIR and Raman spectrum analyses indicate films made of these polyesters effectively cover calcium phosphate–titanium dioxide photocatalysts, retard surface cracks, and slow down decomposition, caused by UV light. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

我国钛白粉行业将持续健康发展

从我国钛白粉行业的发展现状及硫酸法生产钛白粉工艺已由传统型向清洁生产型转变的事实,阐述了我国钛白粉产业仍具有较大的需求量和市场空间。并列举了一系列有助于清洁生产型硫酸法钛白粉发展的相关政策法规,表明在环保与经济效益双赢的情况下、在国家相关政策的支持与引导下我国钛白粉将持续健康发展。     

Conditions for the production of pigmentary titanium dioxide of rutile and anatase modifications by ilmenite processing with ammonium fluoride

The process of ammoniac precipitation of hydrated titanium dioxide from a solution of ammonium hexafluorotitanate obtained during ilmenite processing by ammonium fluoride with the further sublimation separation of titanium tetrafluoride has been studied. The dehydration of hydrated titanium dioxide has been studied. The phase structure of titanium dioxide, depending on the thermal treatment and precipitation conditions, has been investigated. The size of the sample particles has been studied with the method of electron microscopy. The conditions of rutile and anatase pigments production have been determined.     

2011年钛白粉行业运行情况浅析

从2011年钛白粉总产量及产品分布、产能集中度、产量区域性分布、进出口、钛矿资源需求等五大方面全面分析了2011年钛白粉行业的运行情况及发展趋势,表明其呈现5个特征:总产能进一步扩张、实现产量的增幅与新增产能的增幅大体相当、钛白粉品质有较大幅度的提升、钛白粉及钛原料价格不定、政府调控力量得到提升。     

Textile with immobilised nano titanium dioxide for repeated discoloration of CI Reactive Black 5 under UV‐A

A commercially available catalyst with high photocatalytic activity (Degussa p‐25) was immobilised on a comparatively inexpensive substrate that included cotton/polyester knitted fabric by citric acid under sonication. Scanning electron microscopy and energy‐dispersive X‐ray spectroscopy analysis revealed the presence of nano titanium dioxide on the surface of the fabric. Discoloration of CI Reactive Black 5 in aqueous solution was successfully carried out by adding a piece of nano titanium dioxide‐treated fabric into the dye solution under UV‐A irradiation. The ultraviolet–visible spectra indicated complete discoloration of CI Reactive Black 5 dye solutions. CI Reactive Black 5 solution, along with electrolytes including sodium sulphate and calcium carbonate, was also successfully discoloured with lower efficiency. Further, the photocatalytic properties of the nano titanium dioxide‐immobilised fabric did not change after dye solution discoloration and it was used several times for discoloration of the same solutions. The proposed system can be developed on a large scale.     

Plasma induced grafting of PSt onto titanium dioxide powder. II

Grafting of polystyrene (PSt) onto titanium dioxide powder was investigated in this study. The graft polymerization reaction was induced by N₂ plasma treatment of the surfaces of the titanium dioxide powder. IR and XPS results showed that PSt was grafted onto the titanium dioxide powder. The crystal structure of the titanium dioxide powder observed by XRD spectra was unchanged after plasma graft polymerization. In the grafting reaction, the grafting yield increased with the plasma power, the plasma treatment time, and the grafting reaction, but it increased first then decreased after reaching 50°C. The type of monomers also has an effect on the grafting yield. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2112–2117, 2005     

Gentamicin Loaded Electrospun Poly(ε-Caprolactone)/TiO2 Nanocomposite Membranes with Antibacterial Property against Methicillin Resistant Staphylococcus aureus

In this study, electrospun poly(ε-caprolactone)/titanium dioxide nanocomposite membranes were fabricated and characterized. Fourier transform infrared analysis showed an increase in absorbance of vibrational peaks of poly(ε-caprolactone) as the titanium dioxide nanoparticle concentration was increased. From the X-ray diffraction spectra, it was observed that the incorporation of titanium dioxide nanoparticles does not affect the crystalline structure of the poly(ε-caprolactone); instead, the degree of crystallinity has been increased significantly. However, at higher concentrations of titanium dioxide nanoparticles, crystallinity was decreased to a lower value. Differential scanning calorimeter thermograms have also confirmed this tendency. Finally, efficacy of gentamicin-loaded poly(ε-caprolactone)/titanium dioxide nanocomposite membranes against a wound isolate of methicillin-resistant Staphylococcus aureus has been evaluated. The results demonstrated that poly(ε-caprolactone)/titanium dioxide nanocomposite membranes can synergistically act with gentamicin to inhibit the growth of methicillin-resistant S. aureus.     

二氧化钛纳米管的制备、改性及应用

二氧化钛纳米管因其特殊的形貌和高度有序的特性成为了目前研究的热点之一.本文系统回顾了近年来有关二氧化钛纳米管的相关研究,着重阐述了二氧化钛纳米管的制备方法,主要包括模板法、阳极氧化法、水热法;在此基础上,详细论述了掺杂、复合等对二氧化钛纳米管进行改性的方法;并简要介绍了二氧化钛纳米管及其复合材料在环境、能源等领域的应用.最后,展望了二氧化钛纳米管的主要研究方向是对形成机理、管形貌调控、表面改性等方面做进一步研究,以期为后续的研究提供参考.     

PET聚酯缩聚用改性二氧化钛催化剂的制备研究

设计并制备了一种表面硅烷偶联剂KH560改性的二氧化钛,并用红外、透射电镜、XRD粉末衍射和N2吸附比表面积对其进行表征。该催化剂是由许多很小的无定形二氧化钛粒子组成的团聚体,其表面富含大量的羟基。该催化剂较Sb2O23的催化活性高许多,而且所得产品的色相较未改性的二氧化钛有明显的改善。     

Determination of titanium dioxide in soaps by furnace atomic absorption spectrometry

A procedure for the determination of titanium dioxide in soaps by furnace atomic absorption spectrometry is described. The method has the advantage of being rapid and simple. After the soap is dispersed in water, the titanium dioxide content is determined directly without any preliminary treatment with acids and bases to solubilize the titanium dioxide.     

涂料用钛白粉的评估和测试方法

以醇酸树脂为成膜物质,通过加入不同的钛白粉,分别制得5种醇酸涂料。通过测试钛白粉的吸油量,涂料的细度,光泽,QUVA老化试验,湿热试验和户外暴晒试验,考察5种钛白粉的区别,并优化选择得到性能最佳的钛白粉,为钛白粉的筛选提供了一种简单高效的方法。     

Calcium oxide crucibles

Conclusions A new technique has been developed for making crucibles from calcium oxide by casting an alcohol suspension in ceramic molds. The crucibles cast in these molds are prefired at 1000–1100°. The temperature of the final firing is 1650°.The porosity of the crucibles depends on the firing temperature of the compacts and the addition of the titanium dioxide. The best firing temperature for compacts is 1500–1550°, and the optimum amount of titanium dioxide to be added is 1.5%.When made, the crucibles should be kept in desiccators; crucibles made of pure calcium dioxide in the paraffined form and those with the addition of titanium dioxide can be kept uncovered for about 6 months.