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In this present study lanthanum hexa aluminate powder was prepared by using chemical precipitation and filtration technique. Powder sample is characterized in terms of composition, morphology, structure, particle size and using complementary techniques such as X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM). It has been observed that the developed powder will have a hexagonal structure with magneto plumbite phase and the particles were obtained have an average grain size of 75 nm.

A phase diagram of the Na2O–PbO–H2O system at 130 °C was studied using Schreinemakers's method, to provide fundamental data for producing PbO via hydrometallurgical process. In the phase diagram, saturated solubility of PbO has two maximum values vs the sodium hydroxide concentration in the solution. The equilibrium solid phases of lead oxide (PbO), sodium plumbite hydroxide (Na2O·PbO·H2O) and sodium hydroxide (NaOH) were identified in the different alkali concentration regions, which is different from that at low temperature presented in literature. Copyright © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.

In article number 1900381, Jian‐Qiang Wang, Shuao Wang, and co‐workers develop a family of [Ln6O8]‐encapsulating polyplumbite clusters with highest adsorption capabilities toward ReO4 − among all inorganic materials, representing a new family of polyoxometalates based on Group 14 elements with application potentials in the nuclear fuel cycle and overcoming the critical drawbacks of low sorption capacity and poor selectivity for traditional inorganic anion‐exchange materials toward ReO4 −/TcO4 − sequestration.

Various types of polyoxometalates (POMs) have been synthesized since the 19th century, but their assortment has been mostly limited to Groups 5 and 6 metals. Herein, a new family of POMs composed of a carbon group element as the addenda atoms with two distinct phases, LnPbOClO4‐1 (Ln = Sm to Ho, Y) and LnPbOClO4‐2 (Ln = Er and Tm) is reported. Both structures are built from [Ln6O8] rare‐earth metal hexamers being incorporated in [Pb18O32]/[Pb12O24] polyplumbites, and unbound perchlorates as charge‐balancing anions. Impressively, YPbOClO4‐1 and ErPbOClO4‐2 exhibit exceptional uptake capacities (434.7 and 427.7 mg g−1) toward ReO4 −, a chemical surrogate for the key radioactive fission product in the nuclear fuel cycle 99TcO4 −, which are the highest values among all inorganic anion‐exchange materials reported until now. The sorption mechanism is clearly elucidated and visualized by single‐crystal‐to‐single‐crystal structural transformation from ErPbOClO4‐2 to a perrhenate‐containing complex ErPbOReO4, revealing a unique ReO4 − uptake selectivity driven by specific interaction within Pb···O‐ReO3 − bonds.

A sputter-deposited strontium ferrite film with perpendicular anisotropy has been developed. The film, composed of La0.33Sr0.67Co0.25Fe11.75O19, has been fabricated directly on quartz glass substrates by radio frequency magnetron sputtering with various heat treatments. The structural and magnetic property dependence of those films on heat treatments has also been studied. The optimized condition is the heat treatment of in situ heating at 400°C and post-annealing at 850°C–900°C. When post-annealing temperature exceeds 900°C, parasitic phases of γ-Fe2O3 and LaFeO3 appear and gradually increase; meanwhile, the magneto plumbite phase gradually decreases. High c-axis perpendicularly oriented films with the coercivity (4148 Oe), remanence squareness ratio (0.89) and perpendicular magnetic anisotropy energy density (1.65 × 106 erg/cm3) are achieved, which is attributed to the single magneto plumbite phase with compact platelet grains and almost complete (0 0 l) texture of the c-axis normal to the film plane.

A series of polycrystalline M-type hexagonal ferrites with the formula BaFe12-2xZnx NbxO19 (x = 0.2, 0.4, 0.6, 0.8 mol%) have been synthesized by the sol-gel method. The composition and microstructure govern the magnetic properties of ferrites. The XRD analysis shows the formation of pure magneto plumbite phase without any other impurity phases. The Zn-Nb substitutions in barium hexaferrite have been confirmed through magnetic measurements. The results show that the magnetic properties are closely related to the distributions of Zn-Nb ions on the five crystallographic sites. The saturation magnetization and coercivity increase with increasing Zn-Nb concentration.

Various types of polyoxometalates (POMs) have been synthesized since the 19th century, but their assortment has been mostly limited to Groups 5 and 6 metals. Herein, a new family of POMs composed of a carbon group element as the addenda atoms with two distinct phases, LnPbOClO4‐1 (Ln = Sm to Ho, Y) and LnPbOClO4‐2 (Ln = Er and Tm) is reported. Both structures are built from [Ln6O8] rare‐earth metal hexamers being incorporated in [Pb18O32]/[Pb12O24] polyplumbites, and unbound perchlorates as charge‐balancing anions. Impressively, YPbOClO4‐1 and ErPbOClO4‐2 exhibit exceptional uptake capacities (434.7 and 427.7 mg g−1) toward ReO4−, a chemical surrogate for the key radioactive fission product in the nuclear fuel cycle 99TcO4−, which are the highest values among all inorganic anion‐exchange materials reported until now. The sorption mechanism is clearly elucidated and visualized by single‐crystal‐to‐single‐crystal structural transformation from ErPbOClO4‐2 to a perrhenate‐containing complex ErPbOReO4, revealing a unique ReO4− uptake selectivity driven by specific interaction within Pb···O‐ReO3− bonds.

The electrodeposition of lead on to a copper substrate from a plumbite solution, 0.1 M Pb(NO 3 ) 2 + 0.2 M sorbitol + NaOH, was investigated over a range of concentrations of the hydroxide. Interactions between the copper electrode surface and the lead deposit were investigated by the voltammetric technique. From these experiments, it was concluded that underpotential deposition (upd) of lead does not occur on copper and that lead nucleation occurs as soon as deposition is operative from −0.78 V. Energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM) of the lead films corroborates this result. Lead films obtained at −0.78 and −0.90 V were adherent and could be used as a support in battery plates, but this adhesion of lead to copper cannot be attributed to upd. SEM analysis showed that films produced at potentials down to −0.90 V were smooth and that this is the critical potential for a transition from dense to pyramidal or dendritic crystals patterns. The dendritic crystallites can be transformed into a high-purity lead powder.

The potentiodynamic electrodeposition of lead on a 1010 steel substrate from a new electrolytic solution was studied in order to establish whether sorbitol additive is suitable for the production of lead film for use in lead batteries and whether this polyalcohol can be used in lead scrap recycling. It was observed that the presence of sorbitol in the plating bath proved to be critical, since in its absence it was impossible to prepare solutions of plumbite in NaOH

Physical Chemistry Chemical Physics 15, 8506-8519 (2013). doi:10.1039/c3cp51348c, For the first time a detailed structural model has been determined which shows how the lone-pairs of electrons are arranged relative to each other in a glass network containing lone-pair cations. High energy X-ray and neutron diffraction patterns of a very high lead content silicate glass (80PbO·20SiO2) have been used to build three-dimensional models using empirical potential structure refinement. Coordination number and bond angle distributions reveal structural similarity to crystalline Pb11Si3O17 and α- and β-PbO, and therefore strong evidence for a plumbite glass network built from pyramidal [PbOm] polyhedra (m∼ 3-4), with stereochemically active lone-pairs, although with greater disorder in the first coordination shell of lead compared to the first coordination shell of silicon. The oxygen atoms are coordinated predominantly to four cations. Explicit introduction of lone-pair entities into some models leads to modification of the local Pb environment, whilst still allowing for reproduction of the measured diffraction patterns, thus demonstrating the non-uniqueness of the solutions. Nonetheless, the models share many features with crystalline Pb11Si3O17, including the O-Pb-O bond angle distribution, which is more highly structured than reported for lower Pb content glasses using reverse Monte Carlo techniques. The lone-pair separation of 2.85 Å in the model glasses compares favourably with that estimated in α-PbO as 2.88 Å, and these lone-pairs organise to create voids in the glass, just as they create channels in Pb11Si3O17 and interlayer spaces in the PbO polymorphs., Published by RSC Publ., Cambridge

This work aims to make clear whether Pb(II) can be chemically entrapped by ettringite and find out under what conditions this entrapment can take place. In experiment condition, several chemical analytical reagents were used to synthesize the lead analog of ettringite {Pb6[Al(OH)6]2ldr3SO4ldr26H2O}, Ca-Pb ettringite {(Ca,Pb)6 [Al(OH)6]2ldr3SO4ldr26H2O} and plumbite ettringite {3CaOldr Al2O3ldr3CaPbO2ldr31H2O}. The results showed that the lead analog of ettringite and the plumibte ettringite couldn't be synthesized, while Ca-Pb ettringite could be made. This indicated that Pb(II) couldn't be chemically entrapped by ettringite when divalent calcium or sulfate was absent in liquid phase. However, Pb(II) could entrapped into ettringite lattice when calcium ions existed in liquid phase to formed Ca-Pb ettringite. The X-ray diffraction patterns of Ca-Pb ettringite were significantly different from that of Ca-ettringite, indicating that ettringite' lattice been varied after accommodating divalent lead. Experiments on Pb(II) solidified by 100% type I clinker showed that the XRD patterns of the paste at 7-day storage period changed after they doped divalent lead, These further confirmed that Pb(II) could be entrapped into cement minerals including ettringite.

(207)Pb solid-state NMR studies have been conducted on binary lead-group 16 and mixed transition-metal/lead group 16 materials, correlating the NMR chemical shifts of the materials with their structures. The experimental results show that the (207)Pb chemical shifts are strongly influenced by the local electronic structure. Data are reported for lead selenide, lead selenate, calcium plumbate, strontium plumbite, barium plumbite, lead borate, lead zirconate, lead tungstate, lead meta-tantalate, lead niobate, lead molybdate, lead meta-vanadate, lead sulfite, and lead sulfate.

A titrimetric method for determination of lead(II), based on the reaction between plumbite and silver ions, is described. Sodium hydroxide solution is added to the sample until the precipitate of lead hydroxide has redissolved. The solution is then made 0.025M in sodium chloride and titrated with silver nitrate. The titration is monitored with a silver electrode. An error smaller than 0.5% has been obtained for 0.05M lead (II).

Lead monoxide was treated with a strong aqueous sodium hydroxide solution to yield an alkaline solution containing sodium plumbite. The lead from this solution added to unmodified cotton and to cotton containing either acidic or basic groups. The amount of lead added was compared to amounts added from other lead compounds, amounts added from nonaqueous solvents, and to amounts of copper or tin added under similar conditions. Some treated cotton samples contained almost 40% lead. Wrinkle recoveries were improved but flame retardance and rot resistance remained poor. Chemical procedures, electron microscopy, X-ray diffraction, and wrinkle recoveries indicated that a chemical bond was formed between the lead and cotton and that some bonds were intermolecular.

Divalent sulphur in structurally different aliphatic compounds including thiols, sulphides, disulphides and thiocarbonyls is selectively determined by reaction with solid potassium hydroxide at 250–280° for 5–10 min, followed by addition of alkali plumbite whereby lead sulphide is stoichiometrically formed. The excess lead ions are measured by: (a) atomic absorption spectrometry at 217 nm; or (b) potentiometric titration with EDTA at pH 4.6 using the lead ion selective electrode; or (c) visual titration with EDTA using urotropine buffer and Xylenol Orange indicator. An average recovery of 99%, and a mean standard deviation of 0.9% are obtainable with samples down to 2 mg. Divalent sulphur in many aromatic compounds, and tetra- and hexa-valent sulphur in both aliphatic and aromatic compounds do not interfere.

A new, simple, accurate and rapid method is described for the determination of total penicillins in pharmaceutical preparations. The method is based on desulphurization with potassium plumbite whereby one mole of lead sulphide is formed per mole of penicillin. The excess of lead ions is titrated with EDTA at pH 4.5, with use of the lead ion-selective electrode. Results are reproducible within ± 0.5% and compare favourably with those obtained by the procedures of the United States and British Pharmacopoeias.

Summary The electrode kinetics of electroreduction of vanadium(III), cadmium(II), plumbite ion, Mn(NH3)x2+ and nitrobenzene free radical as well as oxidation of the manganese amalgam has been studied at mercury electrodes in a mixture of water with propanol, isopropanol and tert-butanol. With the exception of manganese(II) electroreduction the standard rate constants for other systems at first largely decrease with the increase of the organic component concentration and later slowly increase when the content of alcohol in the mixture increases. These changes of the rate constants were qualitatively explained. The influence of the couble-layer structure on the electrode kinetics in such systems was also studied. The measured formal potentials were compared with those calculated on the basis of the modified Born equation and the differences were explained in terms of selective hydration of ions and liquid junction potential.

Simple, rapid, and accurate methods have been developed for determining vitamin Bx in pharmaceutical preparations without prior separation of the vitamin. The methods are based on the desulfurization reaction with potassium plumbite and measurement of the unreacted lead (II) ions at 217 nm using atomic absorption spectroscopy (AAS), or by titration with EDTA at pH 4.5 with the lead ion selective electrode and Gran's plot. The results compare favorably with those obtained using the USP fluorometric method. Recoveries of pure vitamin Bx averaged 99.1%, with a standard deviation of 0.8%, and 99.0%, with a standard deviation of 0.7%, for the AAS and ion selective electrode procedures, respectively.

Novel thin glassy films formed by heating plumbite-treated cotton in contact with a silicate material were examined by X-ray diffraction, optical microscopy, electron transmission and electron scanning microscopy, electron spectroscopy for chemical analysis, energy-dispersive analysis by X-rays, thermogravimetric analysis, differential thermal analysis, X-ray fluorescence and atomic absorption. The films were formed by an unusual mechanism which was dubbed “element migration”.

A study has been made of the anodic behavior of lead oxide deposits containing 92, 80 and 60%α-PbO2. The non-porous deposits were prepared by electrodeposition from a plumbite bath containing different proportions of 30% formaldehyde solution, acting as a reductant in the cases of 80 and 60%α-PbO2. Measurements of the steady-state oxygen evolution reaction under constant surface conditions of the electrodes, were carried out galvanostatically within the current-density range 30–190μAcm−2. The oxygen overpotential values were found to increase with increasing the amount of superficially formedβ-PbO2 during anodization in sulphuric acid solution. In the proposed mechanism for the o.e.r, the rate determining step is an electron-transfer reaction. Tafel slopes having values of 220±10 mV dec−1 were obtained. Possible interpretation of these higher slopes is given which is based on the dual barrier model. Potential-time decay curves reveal a retarded oxygen diffusion process.

A new method for the estimation of lead, based on its oxidation from the bivalent to the quadrivalent state by alkaline permanganate has been devised. The reaction takes place so rapidly in the presence of a mixture of ZnO and HgO that it can be followed potentiometrically. Oxidation of sodium plumbite with KMn0 4 leads to the formation of PbO and MnO. Reduction of KMnO4 with Pb +2 ions or with sodium plumbite proceeds almost quantitatively in 2.5N NaOH in the absence of Ba +2 ions and in 1–1.5N NaOH in the presence of these ions. Under these conditions Pb +2 Pb +1 and Mn0 4 MnO 4 -2 , provided that the lead solution is not added too rapidly.

Wools varying widely in diameter and crimp. from sheep of several breeds and ages. were stained with various reagents chosen to give high contrast between ortho- and paracortical segments. The brown to black sulfide stain produced in wools by sodium plumbite, selective for the paracortex, was measured quantitatively and observed to in crease with diameter. The greatest rate of change occurs in the fine diameter region. Wools shorn from sheep at different ages show lead sulfide staining increasing with age at shearing. Wool fibers which have been elongated or supercontracted show increased staining, which reflects the mechanical damage. The same wools were stained with acid nickelous nitrite, preferentially staining the ortho segment. It was verified that in this case the order of staining of the various wools is the reverse of that with plumbite. Solubility in an aqueous solution of urea and monothioglycol is shown to increase regularly with the degree of staining in the nickel solution. Bromine water also preferentially stains the orthocortex. Finally, paralleling the staining behavior, the stress in wool at 30% extension (wet) increases generally with diameter as well as with increasing maturity of the sheep.

The extremely sluggish oxidation of scrap steel can be substantially accelerated by pretreating the charge in an aqueous solution or suspension of the sodium salt of certain oxyacids. A requirement is that the acid anhydride possess a low melting point. Hence, V 2 O 5 , MoO 3 , PbO, Bi 2 O 3 and Sb 2 O 3 , as present in solutions of vanadate, molybdate, plumbite, bismuthite and antimonite, respectively, are suitable accelerators. Oxidation acceleration with bismuthite and antimonite increases with both concentration of the accelerator and pretreatment time, suggesting a hydrolytic displacement reaction by which the promoter oxide is impregnated on the steel surface. The accelerated oxidation curve of various steels remains essentially the same despite wide variabilities in the kinetic curves of untreated steel batches. The degree of oxidation acceleration is inversely correlated with the melting point of the oxide promoter.

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