Potassium Lithium Titanate Research Articles

ChemInform Abstract: A Green Synthesis of a Layered Titanate, Potassium Lithium Titanate; Lower Temperature Solid‐State Reaction and Improved Materials Performance.

AbstractKxTi2‐x/3Lix/3O4 (x: 0.8) is prepared by solid state reaction of K2CO3, Li2CO3, and TiO2 in a molar ratio of 2.4:0.8:10.4 (800 °C, 20 h).

A green synthesis of a layered titanate, potassium lithium titanate; lower temperature solid-state reaction and improved materials performance

Abstract A layered titanate, potassium lithium titanate, with the size range from 0.1 to 30 µm was prepared to show the effects of the particle size on the materials performance. The potassium lithium titanate was prepared by solid-state reaction as reported previously, where the reaction temperature was varied. The reported temperature for the titanate preparation was higher than 800 °C, though 600 °C is good enough to obtain single-phase potassium lithium titanate. The lower temperature synthesis is cost effective and the product exhibit better performance as photocatalysts due to surface reactivity.

Effects of reaction parameters on solution combustion synthesis of lepidocrocite-like K0.80Ti1.733Li0.267O4: phase formation and morphology evolution

A lepidocrocite-like potassium lithium titanate K0.80Ti1.733Li0.267O4 (KLTO) with layered structure was synthesized by an auto-igniting solution combustion method using glycine and metal (Ti, K and Li) nitrate as reactants. The crystalline structure and morphology of the as-prepared product were examined using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. Effects of reaction parameters such as ignition temperature and oxidizers to fuel ratio on the phase formation and morphology evolution are investigated in this paper. A pure phase of KTLO was obtained at a low temperature (650 °C) within several minutes. Excessive glycine added into the aqueous precursor solution facilitated the synthesis of a pure and well-crystallized product. As-prepared particles exhibited plate-like shape with a length of 5–20 μm and a thickness of about 2 μm. No residual organic compound existed in the product. After the as-prepared product was post solution combustion heat-treated (1100 °C for 2 h), the particles became uniform in size with smooth surface and well-defined crystalline structure. The product exhibited excellent ion-exchange, intercalation, and exfoliation properties. The exfoliated titania nanosheets are characterized by high two-dimensional anisotropy with a thickness of about 20 nm and a lateral size ranging from sub-micrometers to several tens of micrometers.

SYNTHESIS AND CHARACTERIZATION OF PLATE-LIKE TITANATE/COBALT BLUE PIGMENT COMPOSITES

Plate-like titanate/cobalt blue pigment composite was successfully synthesized by mixing cobalt blue ( CoAl 2 O 4) pigment nanoparticles with plate-like lepidocrocite-type potassium lithium titanate ( K 0.8 Li 0.27 Ti 1.73 O 4, PLT) microparticles in water in order to improve the comfort and covering ability when applied on skin as cosmetics. PLT was synthesized by KCl flux method at 1000°C for 5 h using K 2 CO 3, Li 2 CO 3 and TiO 2 as starting materials, while CoAl 2 O 4 nanoparticle was synthesized by mixing Co ( NO 3)2 ⋅ 6 H 2 O and Al ( NO 3)3 ⋅ 9 H 2 O with the molar ratio of Co:Al 1:6 at pH 9 followed by calcination at 1000°C for 1 h. The morphology of the PLT/ CoAl 2 O 4 composite strongly depended on the solution pH. Since in a low pH solution, the surface of PLT was negatively charged, while that of cobalt blue was positively charged, CoAl 2 O 4 nanoparticles were homogenously coated on the surface of PLT by electrostatic attraction force. PLT/ CoAl 2 O 4 composites obtained showed nice feeling, high flickering pearlescent, excellent UV-shielding characteristic and novel blue color.

The preparation and characterization of tabular, pearlescent Fe-doped potassium lithium titanate

Potassium chloride was used as flux to prepare tabular crystals of both potassium lithium titanate and Fe-doped potassium lithium titanate employing an optimum mass ratio of flux:raw materials. The effects of the dopant and its concentration and the calcination temperature on the morphology of the Fe-doped potassium lithium titanate were investigated. The crystal phases and optical properties of Fe-doped potassium lithium titanate were characterized using X-ray diffraction analysis and UV–vis spectrophotometry, respectively. The influence of dopant concentration on the colour, band gap narrowing and lattice constants of Fe-doped potassium lithium titanate are discussed.

Synthesis of broad-spectrum UV-shielding plate-like titanate/calcia-doped ceria composite in different pH solution

In order to improve the comfort when applied on skin without compromising the ultraviolet (UV)-shielding ability of calcia-doped ceria (Ce 1− x Ca x O 2− x ) (donated as: CDC) nanoparticles, the inorganic composite composed of plate-like potassium lithium titanate (K 0.8Li 0.27Ti 1.73O 4) (donated as: PLT) substrate coated with CDC nanoparticles was prepared by a wet chemical method at different solution pH values. Here, PLT possessing UV-shielding ability were used to improve the comfort and covering ability of CDC. The isoelectronic points (IEP) of PLT and CDC were pH 2.5 and ca. 7, respectively, indicating the electrostatic attraction between negatively charged PLT substrate and positively charged CDC nanoparticles can be expected at pH between 2.5 and 7. The PLT/CDC composites with different CDC contents were prepared at pH 6.5 and 12.0 with and without hetero coagulation. The broad-spectrum UV-shielding material with good comfort and low oxidation catalytic activity was successfully synthesized by the combination of PLT and CDC. The influence of pH on the properties of PLT/CDC was evaluated.

Immobilization of Hemoglobin at the Galleries of Layered Lepidocrocite-Related Potassium Lithium Titanate

The exfoliated nanosheets from the layered potassium lithium titanate K0.8Ti1.73Li0.27O4 can be assembled with the hemoglobin through the electrostatic attraction under mild conditions. The immobilized enzyme has regularly layered structure based on the small angel X-ray diffraction. The preparation method is low cost and the maximum bounding capacity of enzyme is large. The enzyme activity study showed that the immobilized Hb retained enzyme-like peroxidase activity, and the activity increased along with the increase of the interlayer distances. Michaelis-Menten model methods were used to study the peroxidase activity.

Panoscopic Assembling and UV‐Shielding Properties of Calcia‐Doped Ceria with Micaceous Lepidcrocite Type Potassium Lithium Titanate via Soft Chemical Processes

In order to attain further performance improvements concerning UV‐shielding, calcia‐doped ceria (Ce0.8Ca0.2O1.8) nanoparticles were coated on micaceous lepidocrocite‐type potassium lithium titanate (K0.8Li0.27Ti1.73O4), 10–20 μm in diameter via soft solution processes, where the micaceous titanate was prepared by reacting K2CO3, Li2CO3 and TiO2 using K2MoO4 flux at 950°C. After putting micaceous potassium lithium titanate particles in deionized water at 40°C, appropriate quantities of 3 M NaOH aqueous solution and 0.8 M CeCl3‐0.2 M CaCl2 mixed aqueous solution were simultaneously dropped, where the solution was stirred and pH was kept at 12 through the reaction. Then, the desired amount of 2 M H2O2 solution was added and pH was also kept at 12. The slurry was filtrated and washed with water and methanol. The precipitate was fired at 700°C for 1 h to obtain micaceous K0.8Li0.27Ti1.73O4 coated with white Ce0.8Ca0.2O1.8 nanoparticles. Such panoscopic assembling successfully improved the comfort of the product when wearing it on the skin without compromising the UV‐shielding ability, meanwhile greatly reducing the oxidation catalytic activity.

Synthesis and Characterization of Plate-like Potassium Lithium Titanate /Calcia-doped Ceria Composite by Different Coating Technology

Synthesis and Characterization of Plate-like Potassium Lithium Titanate /Calcia-doped Ceria Composite by Different Coating Technology

UV Shielding performance enhancement of CaO doped ceria by coupling with plate-like K0.8Li0.27Ti1.73O4

CaO-doped ceria is of potential interest as an ultraviolet (UV) radiation blocking material in personal care products because of its excellent UV light absorption property and low catalytic ability for the oxidation of organic materials. The performance of CaO-doped ceria needs more enhancements through further control of its oxidation catalytic activity and improvement of its covering ability. The oxidation catalytic activity of CaO-doped ceria may be further reduced by coating with amorphous silica. Generally, CaO-doped ceria do not provide a good coverage for human skin because of the agglomeration of the nanoparticles. The plate-like particles can be used to enhance the covering ability of CaO-doped ceria. Therefore, CaO-doped ceria (Ce0.8Ca0.2O1.8)/plate-like potassium lithium titanate (K0.8Li0.27Ti1.73O4) nanocomposite was synthesized followed by subsequent silica coating.

(Bi1/2Na1/2)TiO3-(Bi1/2K1/2)TiO3-(Bi1/ 2Li1/2)TiO3-BaTiO3 Lead-Free Ceramic Fibres Fabricated by a Powder-Based Extrusion Method

Lead-free bismuth sodium potassium lithium titanate—barium titanate [0.885 (Bi1/2Na1/2)TiO3-0.05(Bi1/2K1/2)TiO3–0.015(Bi1/2Li1/2)TiO3-0.05BaTiO3, BNKLBT-1.5] fibres have been fabricated by a powder-based extrusion method. The ceramic fibres with 400 μ m diameter were well-crystallized after being calcined at 800°C and sintered at 1170°C. After being poled, the electromechanical coupling coefficient k33 of the fibre is 0.55 while other properties are comparable to those a ceramic disc. The BNKLNT ceramic fibres prepared by the powder-based extrusion method have good piezoelectric and ferroelectric properties and have potential to replace lead zirconate titanate (PZT) fibres in various device applications.

Synthesis and silica coating of calcia-doped ceria/plate-like titanate (K 0.8Li 0.27Ti 1.73O 4) nanocomposite by seeded polymerization technique

Calcia-doped ceria is of potential interest as an ultraviolet (UV) radiation blocking material in personal care products because of the excellent UV light absorption property and low catalytic ability for the oxidation of organic materials superior to undoped ceria. In order to reduce the oxidation catalytic activity further, calcia-doped ceria was coated with amorphous silica by means of seeded polymerization technique. Generally, nanoparticles of inorganic materials do not provide a good coverage for human skin because of the agglomeration of the particles. The plate-like particles are required to enhance the coverage ability of inorganic materials. This can be accomplished by synthesis of calcia-doped ceria/plate-like potassium lithium titanate (K 0.8Li 0.27Ti 1.73O 4) nanocomposite with subsequent silica coating to control catalytic activity of calcia-doped ceria. Calcia-doped ceria/plate-like potassium lithium titanate nanocomposite was prepared by soft chemical method followed by silica coating via seeded polymerization technique. Silica coated calcia-doped ceria/plate-like potassium lithium titanate nanocomposite was characterized by X-ray diffraction, SEM, TEM, XPS and FT-IR.

Synthesis and UV-shielding Property of Plate-like Potassium Lithium Titanate Coated with Calcia-doped Ceria Nanoparticles

In order to attain further performance improvements concerning UV-shielding, the synthesis parameters of plate-like lepidocrocite related potassium lithium titanate were optimized and calcia-doped ceria (Ce0.8Ca0.2O1.8) nanoparticles were coated on plate-like potassium lithium titanate (K0.8Li0.27Ti1.73O4), 10-20 μm in diameter via solution processes, where the plate-like titanate was prepared by reacting K2CO3, Li2CO3 and TiO2 using KCl flux at 950°C. After putting plate-like potassium lithium titanate particles in deionized water at 40°C, appropriate quantities of 3 M NaOH aqueous solution and 0.8 M CeCl3-0.2 M CaCl2 mixed aqueous solution were simultaneously dropped, where the solution was stirred and pH was kept at 12 throughout the reaction. Then, the desired amount of 2 M H2O2 solution was added and pH was also kept at 12. The slurry was filtrated and washed with water and methanol. The precipitate was fired at 700°C for 1 h to obtain plate-like K0.8Li0.27Ti1.73O4 coated with white Ce0.8Ca0.2O1.8 nanoparticles. Such panoscopic assembling successfully improved the comfort of the product when wearing it on the skin without compromising the UV-shielding ability, meanwhile greatly reducing the oxidation catalytic activity.

Particle size control of plate-like lepidocrocite-related potassium lithium titanate through optimization of synthesis parameters

Platy particles are required to enhance the covering ability of inorganic UV-shielding materials. A plate-like lepidocrocite-type potassium lithium titanate, K 0.8Li 0.266Ti 1.734O 4 represents a proper candidate as a support for inorganic UV-shielding materials. Optimization of preparation conditions of lepidocrocite-type potassium lithium titanate, K 0.8Li 0.266Ti 1.734O 4, is required to obtain medium-size plate-like titanate of 5–50 μm in diameter that provide good coverage of inorganic UV-shielding materials for the human skin. A plate-like lepidocrocite-type potassium lithium titanate, K 0.8Li 0.266Ti 1.734O 4, was synthesized by calcing K 2CO 3, Li 2CO 3 and TiO 2 mixtures in the presence of KMoO 4 flux. The influences of firing temperature, time, weight ratio of flux to raw materials and Li content were investigated. The plate-like potassium lithium titanate, K 0.8Li 0.266Ti 1.734O 4, with ca. 20 μm in diameter, was obtained with flux/raw materials weight ratio of 50:50 at 1000 °C for 2 h.

Oversized Titania Nanosheet Crystallites Derived from Flux-Grown Layered Titanate Single Crystals

This paper reports on the synthesis and characterization of oversized titania nanosheets derived from single crystals of a potassium lithium titanate, K0.8Ti1.73Li0.27O4. The single crystals with a lateral size of over 1 mm were obtained via a melt and recrystallization process in a flux melt. The crystals were converted into an acid-exchanged form of H1.07Ti1.73O4·H2O, and then was reacted with aqueous tetrabutylammonium (TBA) ions at various concentrations. X-ray diffraction analysis revealed that the titanate crystals exhibited high degrees of swelling, and exfoliated single sheets were obtained at a molar TBA dose of 0.5−1 with respect to the exchangeable protons in H1.07Ti1.73O4·H2O. Observations by transmission electron microscopy and atomic force microscopy detected very large nanosheet crystallites with a lateral size of several tens of micrometers. Some wrinkles and cracks within the crystallites indicated that they were highly flexible and also fragile.