Crystal Growth and Color Tuning of Large Mn(POOH)·3HO Crystals via an Evaporation-Assisted Aqueous Route at Room Temperature.

Large Mn(POOH)·3HO crystals have been prepared from aqueous solutions containing MnCl and (NH)HPO by an evaporation-induced crystal growth technique. The slow solvent evaporation at room temperature maintained the supersaturation of the precursor solution for a long time, resulting in the continuous growth of Mn(POOH)·3HO crystals. The addition of citric acid as a chelating agent and increasing the total volume of the precursor solutions helped to maintain the mild supersaturation conditions for a longer time period, and transparent, unbranched Mn(POOH)·3HO crystals above 2 mm in size were produced by aging for 8 weeks.

Preparation of WO-Mica Hybrid Coatings with Electrochromic Properties and Pearl Luster.

Tungsten oxide-mica composites were prepared by adding different amounts of commercial mica (alumina silicate) in order to provide high luster to electrochromic coatings. The mechanical stability was sustained for up to 50 weight % mica for application in aqueous medium. The electrochemical properties, coloration, and luster were investigated.

Hydrothermal synthesis of dittmarite-group NH(CoMn)PO·HO particles as inorganic violet pigments.

Dittmarite-group NH(CoMn)PO·HO particles were prepared a hydrothermal route. Single-phase platelike NH(CoMn)PO·HO particles were obtained from aqueous solutions containing MnCl·4HO, CoCl·6HO, and (NH)HPO, where the [Mn]/([Co] + [Mn]) mole ratios in the products were controlled by changing the MnCl and CoCl concentrations of the precursor solutions. The vivid violet colour of the ammonium cobalt phosphate (NHCoPO·HO) particles was maintained upon substitution of Co with Mn ions up to = 0.

Aqueous Synthesis of Manganese Phosphate Hydrate Crystals for Creating Inorganic Pigment Materials.

Manganese phosphate hydrate crystals were prepared from aqueous solutions containing MnCl, (NH)HPO, and citric acid. Switzerite [Mn(PO)·7HO] and niahite (NHMnPO·HO) phases were produced at room temperature, and then, hureaulite [Mn(POOH)(PO)·4HO] particles were obtained by aging at 80 °C or by hydrothermal treatment at 100-180 °C. The lower aging temperature (80 °C) and the chelation of Mn ions by citric acid provided a slower crystal growth, resulting in large hexagonal prism blocks of ca.

Aqueous synthesis of tin- and indium-doped WO films evaporation-driven deposition and their electrochromic properties.

M-doped WO (M = Sn or In) films were prepared from aqueous coating solutions evaporation-driven deposition during low-speed dip coating. Sn- and In-doping were easily achieved by controlling the chemical composition of simple coating solutions containing only metal salts and water. The crystallinity of the WO, Sn-doped WO, and In-doped WO films varied with heating temperature, where amorphous and crystalline films were obtained by heating at 200 and 500 °C, respectively.

Correction: Nano- and micro-structural control of WO photoelectrode films through aqueous synthesis of WO·HO and (NH)WO precursors.

[This corrects the article DOI: 10.1039/D0RA01321H.].

Nano- and micro-structural control of WO photoelectrode films through aqueous synthesis of WO·HO and (NH)WO precursors.

Nano- and micro-structured tungsten trioxide (WO) photoelectrode films were prepared through an aqueous solution route. WO precursor layers were deposited on glass substrates through heterogeneous nucleation from (NH)WO aqueous solutions at 50-60 °C. The crystal phase of the precursors changed from WO·HO to (NH)WO with increasing (NH)WO concentration (), which involved a morphological change from micron-scale plates to nano-scale fine particles.

Biomimetic synthesis of nanostructured WO · HO particles and subsequent thermal conversion to WO.

Nanostructured tungsten oxide (WO) particles were prepared in aqueous solution by mimicking biomineralization. Precursor WO · HO particles were generated by ageing a 60°C (NH)WO · 5HO solution containing gelatin. This was followed by heating to 600°C in air for thermal conversion to WO.

Evaporation-Driven Deposition of ITO Thin Films from Aqueous Solutions with Low-Speed Dip-Coating Technique.

We suggest a novel wet coating process for preparing indium tin oxide (ITO) films from simple solutions containing only metal salts and water via evaporation-driven film deposition during low-speed dip coating. Homogeneous ITO precursor films were deposited on silica glass substrates from the aqueous solutions containing In(NO)·3HO and SnCl·5HO by dip coating at substrate withdrawal speeds of 0.20-0.

Transferability and Adhesion of Sol-Gel-Derived Crystalline TiO Thin Films to Different Types of Plastic Substrates.

Anatase thin films were prepared on various plastic substrates by our recently developed sol-gel transfer technique. Polycarbonate (PC), poly(methyl methacrylate) (PMMA), polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polyether ether ketone (PEEK), and polyvinylidene chloride (PVDC) were employed as plastic substrates. A Si(100) substrate was first coated with a polyimide (PI)/polyvinylpyrrolidone (PVP) mixture layer, and an alkoxide-derived titania gel film was deposited on it by spin-coating.

Evaporation-Driven Deposition of WO₃ Thin Films from Organic-Additive-Free Aqueous Solutions by Low-Speed Dip Coating and Their Photoelectrochemical Properties.

We prepared tungsten trioxide (WO3) photoelectrode films from organic-additive-free aqueous solutions by a low-speed dip-coating technique. The evaporation-driven deposition of the solutes occurred at the meniscus during low-speed dip coating, resulting in the formation of coating layer on the substrate. Homogeneous WO3 precursor films were obtained from (NH4)10W12O41·5H2O aqueous solutions and found to be crystallized to monoclinic WO3 films by the heat treatment at 400-700 °C.

Spontaneous Pattern Formation Induced by Bénard-Marangoni Convection for Sol-Gel-Derived Titania Dip-Coating Films: Effect of Co-solvents with a High Surface Tension and Low Volatility.

Evaporation-driven surface tension gradient in the liquid layer often causes the convective flow, i.e., Bénard-Marangoni convection, resulting in the formation of cell-like patterns on the surface.

Superior properties of silica thin films prepared from perhydropolysilazane solutions at room temperature in comparison with conventional alkoxide-derived silica gel films.

Preparation of silica thin films from perhydropolysilazane (PHPS) at room temperature has attracted much attention because it provides a new way to realize silica thin films in a variety of technologies where any high temperature processes should be avoided. Although silica gel films can also be prepared from alkoxides at room temperature by conventional sol-gel method, they are believed to have low mechanical and chemical durability. However, even such alkoxide-derived silica gel films have possibilities to become more durable via condensation reaction and densification when aged at room temperature.

Ceramic thin films on plastics: a versatile transfer process for large area as well as patterned coating.

A versatile technique for fabricating ceramic thin films on plastics has been proposed. The technique comprises (i) the deposition of a gel film by spin- or dip-coating on a silicon substrate coated beforehand with a release layer, (ii) the firing of the gel film into a ceramic film, and (iii) its transfer onto plastics by melting or softening the plastics surface. Reflective anatase and electrically conductive indium-tin-oxide (ITO) thin films were prepared on acrylic resin and polycarbonate substrates.

Spontaneous formation of linearly arranged microcraters on sol-gel-derived silica-poly(vinylpyrrolidone) hybrid films induced by Bénard-Marangoni convection.

Complex, sophisticated surface patterns on micrometer and nanometer scales are obtained when solvent evaporates from solutions containing nonvolatile solutes dropped on a solid substrate. Such evaporation-driven pattern formation has been utilized as a fabrication process of highly ordered patterns in thin films. Here, we suggested the spontaneous pattern formation induced by Bénard-Marangoni convection triggered by solvent evaporation as a novel patterning process of sol-gel-derived organic-inorganic hybrid films.

Aqueous solution synthesis of SnO nanostructures with tuned optical absorption behavior and photoelectrochemical properties through morphological evolution.

We have studied the aqueous solution synthesis of divalent tin oxide (SnO) nanostructures, changes in their optical absorption behavior, and their photoelectrochemical properties. A number of SnO nanostructures including sheets and wires, and their composite morphologies were obtained in aqueous solution containing urea at low temperatures. Parallel control of both oxidation state and morphology was achieved through the urea-mediated solution process.

Spontaneous formation of linear striations and cell-like patterns on dip-coating titania films prepared from alkoxide solutions.

Linear striations and cell-like patterns were spontaneously formed on the dip-coating titania films prepared titanium tetraisopropoxide (Ti(OC(3)H(7)(i))(4)) solutions. Such unique patterns on micrometer scale were arranged parallel to the substrate withdrawal direction. The values of R(Z) (10 point height of irregularities) and S (mean spacing of local peaks) of the patterns increased with increasing film thickness depending on the substrate withdrawal speed for dip-coating, the viscosity of the coating solutions, and the distance from the top edge of films.

Biomimetic synthesis of metal ion-doped hierarchical crystals using a gel matrix: formation of cobalt-doped LiMn(2)O(4) with improved electrochemical properties through a cobalt-doped MnCO(3) precursor.

We have synthesized spinel type cobalt-doped LiMn(2)O(4) (LiMn(2-y)Co(y)O(4), 0 View Article and Find Full Text PDF

Synthesis and applications of SnO nanosheets: parallel control of oxidation state and nanostructure through an aqueous solution route.

Tin monoxide (SnO) nanosheets 5 nm in thickness are generated on substrates through an aqueous solution process under mild conditions. Parallel control of the oxidation state and morphology is achieved by a urea-mediated approach in aqueous solution. The SnO nanosheets form a porous thin film on substrates such as indium tin oxide and carbon nanofiber (CNF).

Matrix-mediated formation of hierarchically structured SnO crystals as intermediates between single crystals and polycrystalline aggregates.

Crystalline SnO grown in a Sn 6O 4(OH) 4 matrix exhibited hierarchical architectures, such as stepped bipyramids, stacked meshes, and rosettes, which were not categorized into the classical assortment of crystal morphologies. The complex architectures consisting of small building units were found to be produced through stacking and/or branching growth accompanied with a decrease in the unit size and degradation of the crystallographic symmetry in their assembly. This particular morphological evolution is presumed to be achieved by increasing the driving force of crystallization in the presence of abundant precursor species supplied from the matrix.

Gene expression in Pre-MBT embryos and activation of maternally-inherited program of apoptosis to be executed at around MBT as a fail-safe mechanism in Xenopus early embryogenesis.

S-adenosylmethionine decarboxylase (SAMDC) is an enzyme which converts S-adenosylmethione (SAM), a methyl donor, to decarboxylated SAM (dcSAM), an aminopropyl donor for polyamine biosynthesis. In our studies on gene expression control in Xenopus early embryogenesis, we cloned the mRNA for Xenopus SAMDC, and overexpressed the enzyme by microinjecting its mRNA into Xenopus fertilized eggs. In the mRNA-injected embryos, the level of SAMDC was enormously increased, the SAM was exhausted, and protein synthesis was greatly inhibited, but cellular polyamine content did not change appreciably.

Crystal growth of metastable rutile-type TixSn1-xO2 solid solutions in an aqueous system.

Nanoscale grains of crystalline TixSn1-xO2 were directly grown over the whole range of [Ti]/([Ti] + [Sn]) ratio (x = 0.00-1.00) in aqueous solutions at near room temperature.