Tin Phosphate Research Articles

Microwave synthesis and physical characterization of tin(II) phosphate glasses

Tin phosphate glasses in the SnO-P2O5 binary diagram have been prepared by using a domestic microwave-heating device. Microwaves provide an extremely facile and automatically temperature-controlled route to the synthesis of glasses due to the specific dielectric properties of each chemical composition. Typical melting time is no longer than 10 min, limiting the oxidation of Sn2+ and the melt can be quenched into glass. The glass transition temperature increases with the SnO content confirming the depolymerization of the vitreous network, as expected by the relative fraction of the different Q n structural units deduced from NMR experiments. Concerning the mechanical properties, the Vickers hardness and the fracture toughness decrease while the thermal expansion coefficient and the different elastic moduli remain constants. These results confirm that those characteristics are not very sensible to structural considerations. On the contrary, the chemical durability of Sn2P2O7, determined from the weight loss method, is 300 times higher than that of Sn(PO3)2. Furthermore, Sn2P2O7 is the only glass composition that exhibits a devitrification phenomenon leading to the low-temperature phase of the crystalline tin(II) pyrophosphate.

Stacked porous tin phosphate nanodisk anodes

Stacked porous octahedral tin phosphate Sn(2)P(2)O(7) nanodisks, with a thickness and a width of 20 nm and 200 nm, respectively, were prepared from quenching hydrothermally prepared (SnHPO(4))(2).H(2)O at 600 degrees C. The first discharge capacity was 600 mA h g(-1) while the capacity retention, even after 220 cycles, was 93%.

Proton Conducting Properties of Sulfonated Poly(etheretherketone) Composite Membranes with Layered Tin Phosphate Hydrates at Intermediate Temperatures

Sulfonated poly(etheretherketone) (SPEEK)/layered tin phosphate hydrate membranes were prepared with a SnP content of 0–50 vol %, and their chemical stability and proton conductivities at were investigated. In the membranes with 25–50 vol % SnP, improved heat resistance, water insolubility, and lower water uptake were confirmed. It is suggested from the results of thermogravimetry–differential thermal analysis and diffuse reflectance Fourier transform infrared spectroscopy that hydrogen bonds were formed at the SPEEK/SnP interfaces and that these bonds are responsible for the improved stability. Proton conductivity was dependent on the absorbed water amount and increased with increasing SnP content in the membranes with 25–50 vol % SnP. The membrane with 50 vol % SnP showed a high conductivity of at under saturated water vapor pressure and a smaller dependence of conductivity on the relative humidity at than the membrane with 25 vol % SnP. The SPEEK/SnP composites have a promising potential as membranes usable at .

Thermal behaviour of tin(II/IV) phosphates prepared by various methods

Tin(II/IV) phosphate was prepared by various synthetic methods. The different methods resulted in tin phosphate with different properties, i.e., different crystalline form and behaviour during thermal treatment. The prepared materials have 3 mol water of crystallisation, which they lose in different ways. Total mass loss was between 20 and 30%. This could be connected with water loss, going generally in two steps in parallel with endothermic processes. At the end of thermal treatment, tin pyrophosphate is obtained, irrespective of the method of preparation used.

Metal (IV) Phosphates as Solid Catalysts for Selective Dehydration of Sorbitol to Isosorbide

Metal (IV) phosphates of tin, zirconium and titanium were used as catalysts for selective dehydration of sorbitol to isosorbide. Tin phosphate showed the highest selectivity to isosorbide with a moderate conversion. The deactivation rates of catalysts were fitted by an empirical Voorhies equation and the results showed tin phosphate had the lowest deactivation rate with the least values of m and n. Thermal analysis showed deactivation rate was in accordance with coke deposition. The acidity caused by functional groups of the catalysts was the direct factor for catalyst lifetime, which was evidenced by NH3-TPD, XRD, IR and Raman characterizations.

Tin Phosphate Electrode Materials Prepared by the Hydrolysis of Tin Halides for Application in Lithium Ion Battery

The synthesis, structural characterization, and electrochemical evaluation as potential anode material for Li ion battery of new materials based on tin phosphate are studied. Hydrothermal treatment...

Investigations of tin (II/IV) phosphates prepared by various methods, Mössbauer study and X-ray diffraction characterization

Using various methods different tin phosphate samples were prepared. One of them was amorphous, while the others were crystalline with monoclinic structure, having unit cell parameters as follows: a=4.586 Å, b=13.618 Å, c=5.818 Å, β=99.61° [Sn (H 2PO 4) 2] and a=8.612 Å, b=4.964 Å, c=15.860 Å, β=98.87° [Sn(HPO 4) 2], respectively. The crystal water content and the method of thermal decomposition of the samples were determined. The chemical composition of the end products of preparations was determined by promt-gamma activation analysis and was found to be Sn:P=1:2 for all samples independent of their preparation method. The oxidation state of tin atoms in samples as determined by Mossbauer spectroscopy was mainly +2 in sample no. 2, while in some other samples it was +4.

Effect of thermal imprinting conditions on fabricated micro/nano patterns in tin phosphate glass

Thermal imprinting conditions of low-softening tin phosphate glass with a composition of 67 mol% SnO-33 mol% P2O5 were investigated using three processing parameters of temperature, imprinting pressure, and holding time. Fabrication conditions of a micro square grid (SG) pattern with a similar depth of silica mold (∼120 nm) were optimized. AFM observations confirmed that the 700 nm × 700 nm SG pattern with ∼120 nm depth could be formed with good reproducibility.

Hydrogen Selective Catalytic Reduction of NOx Assisted by In Situ Ammonia Formation over Pt Catalyst Supported on Fe-doped Tin Phosphate

Abstract In situ formation of ammonia and NOx reduction with high N2 selectivity based on it were observed in the hydrogen selective catalytic reduction (H2-SCR) of NOx over a platinum catalyst supported on a Fe-doped SnP2O7 powder with strong solid acidity even under conditions of high oxygen contents of about 10 vol %.

Preparation of Oriented Titanium Phosphate and Tin Phosphate/Polyaniline Hybrid Films by Electrochemical Deposition

The preparation of hybrid films of metal (Ti and Sn) phosphate nanosheets and polyaniline by simultaneous electrophoretic and electrolytic deposition was performed in an acetonitrile solvent. Emeraldine polyaniline was intercalated between the phosphate nanosheets with a monolayer arrangement. The obtained hybrid films were several tens of micrometers in thickness. The ratio of incorporated polyaniline to metal phosphate in the hybrid films reaches to around 0.45 and 0.30 at suitable concentrations of tetrabutylammonium hydroxide (TBAOH). These amounts correspond with occupancy of polyaniline in the interlayer gallery of several tens percent. Fractions of voids in a horizontal direction were around 22 and 1% in titanium phosphate/polyaniline and tin phosphate/polyaniline hybrid films, respectively. Thus, anodic electrodeposition makes it possible to form thick films of intercalation compounds of alpha-titanium and tin phosphates with polyaniline. These hybrid films were examined for redox activity. The cyclic voltammetry results of these films confirmed that the hybrid films have redox activity by polyaniline. For these voltammograms, the maximum current was observed in the tin phosphate/polyaniline hybrid deposited for 15 min. The redox activity of these hybrids possibly depends on the mesoscopic texture of the film, especially on the amount of voids in a horizontal direction.

Structural Diversity in Organotin Compounds Derived from Bulky Monoaryl Phosphates: Dimeric, Tetrameric, and Polymeric Tin Phosphate Complexes

AbstractMonoaryl phosphates with a bulky aryl substituent have been used to synthesize new organotin clusters and polymers. The equimolar reaction between 2,6‐diisopropylphenylphosphate (dipp‐H2) and Me2SnCl2 in ethanol at 25 °C leads to the formation of [Me2Sn(μ3‐dipp)]n (1), while the reaction of 2,6‐dimethylphenylphosphate (dmpp‐H2) with Me2SnCl2 in either a 1:1 or 2:1 molar ratio proceeds to produce exclusively [Me2Sn(μ‐dmpp‐H)2]n·nH2O (2). Compounds 1 and 2 are 1D polymers with different architectures. In compound 1, the tin atom is five‐coordinate (trigonal bipyramidal). Each dipp ligand bridges three different tin atoms to form an infinite ladder‐chain structure. In 2, each six‐coordinate (octahedral) tin atom is surrounded by four phosphate oxygen atoms originating from four different bridging dmpp‐H ligands, thus forming a spirocyclic coordination polymeric chain. The use of nBu2SnO as the diorganotin source in its reaction with dipp‐H2 leads to the isolation of dimeric [nBu2Sn(μ‐dipp‐H)(dipp‐H)]2 (4), which contains a central Sn2O4P2 unit. There are two chemically different half molecules of 4 in the asymmetric part of the unit cell and hence it actually exists as a 1:1 mixture of [nBu2Sn(μ‐dipp‐H)(dipp‐H)]2 and [nBu2Sn(μ‐dipp)(dipp‐H2)]2 in the solid state. The reaction of the monoorgano tin precursor nBuSn(O)(OH)·xH2O with dipp‐H2 takes place in acetone at room temperature to yield the tetrameric cluster 5, which has different structures in the solution and in the solid state. 31P NMR spectroscopy clearly suggests that 5 has the formula [nBu4Sn4(μ‐O)2(μ‐dipp‐H)8] in solution. The single‐crystal X‐ray diffraction studies in the solid state, however, reveal that compound 5 exists as [nBu4Sn4(μ‐OH)2(μ‐dipp‐H)6(μ‐dipp)2]. The use of compounds 1–4 as possible precursors for the preparation of ceramic tin phosphate materials has been investigated. The thermolysis of 1 at 500 °C leads to the formation of quantitative amounts of Sn2P2O7, while the thermolysis of 2, 3, and 4 under similar conditions results in the formation of SnP2O7. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

Synthesis and characterization of alkali-metal tin(II) phosphates: Na 10Sn 31(HPO 4) 6(P 2O 7) 6(PO 4) 12 and K 2SnP 2O 7

Two new alkali-metal tin(II) phosphates – Na 10Sn 31(HPO 4) 6(P 2O 7) 6(PO 4) 12 ( 1) and K 2SnP 2O 7 ( 2) – were synthesized by high-temperature reactions and structurally characterized by single-crystal X-ray diffraction. Na 10Sn 31(HPO 4) 6(P 2O 7) 6(PO 4) 12 crystallized in the noncentrosymmetric space group P-62 c (No. 190) with a = 9.6445(1) Å, b = 9.6445(1) Å, c = 34.059(6) Å, V = 2743.6(7) Å 3 and Z = 1. K 2SnP 2O 7 crystallized in the monoclinic space group P2 1/ n with a = 9.856(3) Å, b = 6.7244(1) Å, c = 12.225(3) Å, β = 108.240(5)°, V = 769. 5(3) Å 3 and Z = 4. Both structures exhibit a novel open-framework structure. The crystal structure of 1 contains SnO 3 and SnO 4 polyhedra sharing corners with [HPO 4] 2−, [PO 4] 3− and [P 2O 7] 4− groups, which form tunnels of six rings filled with Na + cations and parallel to the c-axis, which are connected via O–Sn–O bridges to form a three-dimensional open framework. The crystal structure of 2 contains SnO 4 seesaw polyhedra sharing corners with diphosphate groups to form a three-dimensional [SnP 2O 7] 2− framework that exhibits a tunnel structure of 10- and 12-membered rings expanding along [011] and [100] with four arrays of K + cations located in channels of the framework.

Syntheses and Crystal Structures of Two New Open‐Framework Tin(II) Phosphates: Sn5O2(PO4)2 and Sn4O(PO4)2

AbstractTwo new three‐dimensional neutral open‐framework tin(II) phosphates, Sn5O2(PO4)2 and Sn4O(PO4)2, were synthesized under hydrothermal conditions with different ratio of tin(II) oxalate, phosphoric acid and 4,4′‐diaminodiphenylmethane. Their crystal structures have been solved by single‐crystal X‐ray diffraction methods. Sn5O2(PO4)2 crystallizes in the space group $P{\bar 1}$ and contains six‐membered ring and twelve‐membered ring channels running parallel to the b axis. Sn4O(PO4)2 crystallizes in the space group P21/n and contains intersecting eight‐membered ring channels. These two compounds have rare trigonal‐planar Sn3O.

Compositional dependence of photoelasticity of tin phosphate glasses

The photoelastic constants (PECs) of transparent SnO-P2O5 (SP) glasses with 52-72 mol% SnO were determined using a frequency stabilized transverse Zeeman He-Ne laser (STZL) at 633 nm. The SP glass samples were melted at 950°C in carbon crucibles and at 1050°C in alumina crucibles. The melting conditions affect the values of glass transition temperature and OH content but have almost no effect on PEC. The PEC varies monotonically with increasing SnO concentration from -0.73 to -1.98 × 10-12 Pa-1.

Synthesis, characterization and adsorption behaviour of TX-100 based Sn(IV) phosphate, a new hybrid ion exchanger

A new hybrid ion exchanger, Triton X-100 based tin(IV) phosphate (TX-100SnP) has been synthesized and characterized by ion exchange and physico-chemical methods such as ion exchange capacity, elution and concentration behaviour, IR, X-ray, TG/DTA and elemental analysis. Its adsorption behaviour has also been studied for some alkaline earths and heavy metal ions in different acidic media. It has been found generally more selective for metal ions as compared to tin(IV) phosphate prepared earlier. For Pb(II), Hg(II) and Fe(III) its selectivity has been found to be exceptionally good. On this basis, some binary separations have been performed involving these metal ions. Thermal studies show a high thermal stability of the material. It retains 54.54% of its i.e.c. at 200°C and 27.27% at 300°C.

Glass-former/glass-modifier interactions and the stress-optic response

The stress-optic response of glass refers to the birefringence induced by application of anisotropic stress. We showed in an earlier publication [M. Guignard, L. Albrecht, J.W. Zwanziger, Chem. Mater. 19 (2007) 286] that this effect may be predicted based on the combination of bond metallicity and coordination number in the glass, and from the combination of these effects a variety of zero stress-optic glasses can be generated. In the present work we study in detail the relation of the structure and the bond metallicity to the stress-optic response in three glasses, two of which show zero and negative stress-optic response while the other shows only positive response. In particular we show by solid-state nuclear magnetic resonance spectroscopy that barium and lead phosphate glasses are much more similar in structure than tin phosphate glass, but that the lead and tin glasses have similar stress-optic response. The reason is the similar bond metallicity, which we explore by first-principles calculations, and the low metal ion coordination numbers that the lead and tin glasses exhibit.

Imprinted optical pattern of low-softening phosphate glass

Thermal imprinting of transparent tin phosphate glass was performed at 250 degrees C using a fine-patterned silica mold. The glass sample was prepared by a conventional melt-quenching method and polished with a roughness of < or =10 nm for imprinting experiments. The imprinting temperature is optimized based on experimental viscosity data. Scanning electron microscope and atomic force microscope observations revealed that a square grid pattern has a surface roughness of < or =10 nm and 5 microm x 5 microm squares with ~1 microm intervals and 90-100 nm depth. Diffraction spots due to the micropattern are demonstrated by illuminating He-Ne laser light.

Electrochemical properties of tin phosphates with various mesopore ratios

Tin phosphates with various mesopore ratios are synthesized with surfactants as templates. The mesopore ratios of the tin phosphates are controlled by adjusting the surfactant: inorganic precursor ratios. As an anode material for Li-ion batteries, the mesoporous and non-mesoporous mixture with a high mesopore ratio exhibits enhanced cycling stability. Compared with the ∼34% (∼135 mAh g −1) capacity retention after 50 cycles of the non-mesoporous tin phosphate (between 2.5 and 0.001 V), the tin-phosphate anodes with mesopore ratios of 42, 82 and 100% show capacity retentions that are enhanced by more than 50%, showing charge capacities of ∼260, ∼290, and ∼325 mAh g −1, respectively (after 50 cycles). The mesoporous structures may alleviate the large volume change of the Sn nanoparticles embedded in the lithium-phosphate matrix during charge–discharge. Cycling tests of the 100% mesoporous tin phosphate between 0.8 and 0.001 V exhibit no capacity decay: ∼325 mAh g −1 remains after 50 cycles. This is probably because re-oxidation of metallic tin with lithium-phosphate matrix does not occur.

Selective polymerization of propylene oxide by a tin phosphate coordination polymer

AbstractOligomeric and polymeric polyether polyols, especially poly(propylene oxide), are used for the production of detergents, nonionic surfactants, washing agents, and cleaners, but they are predominantly used in polyurethane production processes. Tin phosphate coordination polymers show good activity in the selective polymerization of epoxides. The catalyst can be easily synthesized by the condensation of tributyl phosphate and butyl tin trichloride. Investigations of this achiral organotin phosphate condensate in the stereoregular polymerization of propylene oxide, including the properties controlling the molecular weight of the resulting poly(propylene oxide) and structural and mechanistic studies, are presented. Additionally, the polymerization of propylene oxide occurs with high activity, no allyl end groups, just a small number of irregularities, and a high percentage of isotacticity (88%) in the polymer. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3032–3041, 2007

Synthesis of Tin(II) Phosphate Open Frameworks Using Isomers of 1,2‐Diaminocyclohexane as Template

AbstractA novel layered framework of tin(II) phosphate, [Sn4(PO4)3(OH)]2–·[trans‐1,2‐C6H10(NH3)2]2+, has been synthesized under hydrothermal conditions with tin(II) oxalate, phosphoric acid and a mixture of trans‐ and cis‐1,2‐diaminocyclohexane (1,2‐DACH). The compound crystallizes in the monoclinic space group P21/n (No. 14). The channels of the trans‐1,2‐DACH are occluded by hydrogen bonding in the doubly protonated form, which is leached out from the framework. Reaction using only tran‐DACH gives the same compound. For comparison, when cis‐DACH is used as template under the same conditions instead of the mixture of trans and cis isomers, the neutral inorganic phosphate framework (Sn3O)2(Sn2O)2(PO4)4 is formed. It crystallizes in the triclinic space group P$\bar {1}$ (No. 2). These results suggest that trans‐1,2‐DACH is selectively occluded in the framework [Sn4(PO4)3(OH)]2–·[trans‐1,2‐C6H10(NH3)2]2+. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2007)