A Factorial Design Approach for Hydrothermal Synthesis of Phase-Pure AgInO2: A Parametric Optimization Study

Owing to a wide range of industrial applications and fundamental importance, delafossite compounds have gathered tremendous interest in research community. In this study, the formation of hexagonal nanoplates of AgInO₂ mainly dominated by (00l) facets with no metallic Ag impurity, reported using a facile hydrothermal route at 180 °C using KOH as mineralizer by adopting a factorial design approach. Rietveld analysis of the powder XRD pattern and SAED confirms the rhombohedral system of AgInO₂. FE-SEM image shows a uniform hexagonal plate-like morphology with an average width of about 300 nm and thickness of 70 nm. XPS and EDX analysis confirm potassium ion free AgInO₂. A specific surface area of about 48.5 m² g⁻¹ is arrived from N₂ adsorption studies. Temperature-dependent AC impedance measurements revealed an activation energy of 0.24 eV/f.u. Further, TG-DTA studies found that the compound is stable in air up to 595 °C.     

Preparation of Thermosensitive Hollow Imprinted Microspheres via Combining Distillation Precipitation Polymerization and Thiol‐ene Click Chemistry

Hollow molecular imprinted polymer microspheres were prepared by distillation precipitation polymerization with (S)‐(+)‐ibuprofen (S‐IBF) as template molecule and acrylamide (AM) as functional monomer. Using the silicon dioxide (SiO₂, 180 nm) modified by 3‐(trimethoxysilyl)propyl methacrylate (MPS) as the template microspheres, the molecular imprinted shells were coated on successfully (SiO₂@MIPs). The thermosensitive SiO₂@MIPs‐PNIPAM core‐shell microspheres were subsequently prepared by grafting the PNIPAM chains (M_n=1.21×10⁴ g/mol, polydispersity index=1.30), which were prepared by reversible addition‐fragmentation chain transfer (RAFT) polymerization, on the surface of SiO₂@MIPs microspheres via the thiol‐ene click chemistry. The grafting density of PNIPAM brushes on the SiO₂@MIPs microspheres was about 0.18 chains/nm². After HF etching, the hollow imprinted microspheres were finally obtained. For thermosensitivity analysis, the phase transition temperatures of multifunctional nanoparticles were measured by DSL at 25°C and 45°C respectively, and the sizes of the microspheres changed by about 35 nm. The modified microspheres presented excellent controlled release property to S‐IBF, moreover about half amount of the adsorptions passed into acetonitrile‐water solution through the specific holes of imprinted shell at 25°C under vibration.     

Synthesis and characterization of poly(aminoborane) as a new boron nitride precursor

During the solution reaction of NaBH₄/(NH₄)₂SO₄ in tetraglyme to form borazine, polymeric aminoborane (NH₂BH₂)_x has been isolated as a white powder. The powder was characterized by thermal gravimetric analysis/differential scanning calorimetry, infrared and mass spectroscopies, and powder X‐ray diffraction. Solid‐state ¹⁵N and ¹¹B nuclear magnetic resonance firmly proved that the chain‐like poly(aminoborane) evolved a partially condensed B₃N₃ ring structure by dehydrogenative condensation between chains at 200 °C. Pyrolysis of the polymer in a nitrogen stream up to 1400 °C led to a 75% yield of hexagonal boron nitride with an interlayer spacing of 3.37 Å. Copyright © 1999 John Wiley & Sons, Ltd.     

Surface cavities produced by high‐dose nitrogen ion implantation into silicon

Nitrogen ion implantation (24 keV, 4.6 × 10¹⁷ cm^?2) into (100) a p‐type silicon wafer material and a subsequent electron beam annealing at 1100 °C for 15 s under high vacuum conditions leads to the formation of an uneven surface in the implanted region caused by nitrogen bubbles beneath the surface. Annealing at 1200 °C for 300 s results in surface cavities with a mean diameter of 350 nm and a surface coverage of 3–4% and an average depth of ～60 nm. Nuclear reaction analysis reveals that the nitrogen concentration in the as‐implanted state exceeds 57 at%, the value of stoichiometric Si₃N₄. Annealing at 1100 °C for 15 s slightly reduces the nitrogen peak concentration, whereas annealing at 1200 °C for 300 s induces a significant alteration to the shape of the nitrogen depth profile coupled with the lowering of the concentration close to the stoichiometry of Si₃N₄. The results present a new method of producing sub‐micrometre cavities embedded in a thin silicon nitride film on wafer silicon which may lead to novel micro‐electronic and biotechnology applications. Copyright © 2007 John Wiley & Sons, Ltd.     

Facile Green Synthesis of BCN Nanosheets as High‐Performance Electrode Material for Electrochemical Energy Storage

Two‐dimensional hexagonal boron carbon nitride (BCN) nanosheets (NSs) were synthesized by new approach in which a mixture of glucose and an adduct of boric acid (H₃BO₃) and urea (NH₂CONH₂) is heated at 900 °C. The method is green, scalable and gives a high yield of BCN NSs with average size of about 1 μm and thickness of about 13 nm. Structural characterization of the as‐synthesized material was carried out by several techniques, and its energy‐storage properties were evaluated electrochemically. The material showed excellent capacitive behaviour with a specific capacitance as high as 244 F g^?1 at a current density of 1 A g^?1. The material retains up to 96 % of its initial capacity after 3000 cycles at a current density of 5 A g^?1.     

一种新型氧离子导体：La3GaMo2O12

A new oxide ion conductor,La_3GaMo_2O_(12),with a bulk conductivity of 2.7×10~(-2)S·cm~(-1) at 800 ℃ in air at-mosphere was prepared by the traditional solid-state reaction.The room temperature X-ray diffraction data could beindexed on a monoclinic cell with lattice parameters of a=0.5602(2) nm,b=0.3224(1) nm,c=1.5741(1) nm,β=102.555(0)°,V= 0.2775(2) nm~3 and space group Pc(7).Ac impedance measurements in various atmospheres furthersupport that it is an oxide ion conductor.This material was stable in various atmospheres with oxygen partial pres-sure p(O_2)ranging from 1.0×10~5 to 1.0×10~(-7) Pa at 800 ℃.A reversible polymorphic phase transition occurred atelevated temperatures as confirmed by the differential thermal analysis and dilatometric measurement.     

Thin films of vanadium oxide grown on vanadium metal: oxidation conditions to produce V2O5 films for Li‐intercalation applications and characterisation by XPS,AFM, RBS/NRA

Thin films of vanadium oxide were grown on vanadium metal surfaces (i) in air at ambient conditions, (ii) in 5 mM H₂SO₄ (aq), pH 3, (iii) by thermal oxidation at low oxygen pressure (10^?5 mbar) at temperatures between 350 and 550 °C and (iv) at near‐atmospheric oxygen pressure (750 mbar) at 500 °C. The oxide films were investigated by atomic force microscopy (AFM), X‐ray photoelectron spectroscopy (XPS), X‐Ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA). The lithium intercalation properties were studied by cyclic voltammetry (CV). The results show that the oxide films formed in air at room temperature (RT), in acidic aqueous solution, and at low oxygen pressure at elevated temperatures are composed of V₂O₃. In air and in aqueous solution at RT, the oxide films are ultra‐thin and hydroxylated. At 500 °C, nearly atmospheric oxygen pressure is required to form crystalline V₂O₅ films. The oxide films grown at pO₂ = 750 mbar for 5 min are about 260‐nm thick, and consist of a 115‐nm outer layer of crystalline V₂O₅. The inner oxide is mainly composed of VO₂. For all high temperature oxidations, the oxygen diffusion from the oxide film into the metal matrix was considerable. The oxygen saturation of the metal at 450 °C was found, by XPS, to be 27 at.% at the oxide/metal interface. The well‐crystallized V₂O₅ film, formed by oxidation for 5 min at 500 °C and 750 mbar O₂, was shown to have good lithium intercalation properties and is a promising candidate as electrode material in lithium batteries. Copyright © 2005 John Wiley & Sons, Ltd.     

A new route to phosphonium polymer network solids via cyclotrimerization

An organo‐main group network solid having tetrahedral phosphonium vertices was prepared from a diacetyl monomer via a straightforward cyclotrimerization reaction. The network solid composition was examined by FT‐IR spectroscopy and elemental microanalysis, revealing quantitative reaction of carbonyl moieties and a 67% degree of cross‐linking. The reaction yielded a material having a layered structure that is comprised of an amorphous polymer and which is thermally stable up to 370 °C in air with a char yield of 40% upon heating as high as 800 °C under N₂. The polymer is stable to 6 M NaOH(aq ) at 60 °C for 24 h and takes up only 10.63% of water by mass at room temperature. The surface morphology, as examined by AFM, revealed a very smooth as‐prepared film (RMS roughness of 3 nm). The specific surface area measured by BET analysis with N₂ gas is 9 m² g^?1, indicating a type II, nonporous material. Physisorption with CO₂ revealed that the phosphonium network solid has additional affinity for CO₂, suggesting that such materials may have use for applications such as CO₂ capture. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 1620–1625     

Synthesis,Crystal Structure and Magnetic Properties of a 1‐D Polymer, [Cu(NITpPy)2(H2TCB)(H20)]·2H2O

A novel complex [Cu(NnpPy)₂(H_lTCB)(H₁O)]·2H₂O (NITpPy = 2‐(pyrid‐4′‐yl)‐4,4,5,5‐tetramethyl‐1, 3‐dioxoimidazoline; H₂TCB = 1, 5‐dicarboxybenzene carboxylic‐2, 4‐diacid) has been synthesized and characterized by X‐ray crystallography analysis. The crystal structure consists of infinite chains of Cu‐(NITpPy)₂(H₂O) units linked by H₂TCB ligands. The complex crystallizes in triclinic system with space group PI. Crystal data: a = 1.0594(2) nm, b = 1.3830(3) nm, c = 1.5551(3) nm, a = 67.75(3)°, β = 89.83(3)°, γ = 70.54(3)°. The variable magnetic susceptibility studies lead to magnetic coupling constant values of J₁= ?11.18 cm‐¹ (Cu—Rad) and J₂ = ?4.06 cm^?1 (Cu—Cu).     

Hydrothermal Synthesis and Properties of Open-Framework Mixed-valence Iron Phosphates Fe2^111Fe1.5^11（PO4）3 with Three-dimensional Structure

The open‐framework iron phosphate Fe₂^lllFe_1.5^ll,(PO₄)₃ was hydrothermally synthesized and characterized by elemental analysis, IR, EPR, XPS and single crystal X‐ray diffraction analysis. The title compound crystallized in the triclinic, space group P1 with a=0.64724(4) nm, b=0.79651(6) nm, c=0.94229(5) nm, a= 104.447(2)°. β= 108.919(4)°. y= 101.741(4)°, V=0.42302(5) nm³, Z= 1 and R_I (wR₂)=0.0307 (0.0793). Crystal data were collected on a Rigaku R‐AXIS RAPID IP diffractometer with Mo Ka (γ=0.071073 nm) at 293(2) K in the range of 2.43°<Õ <27.46°. The structure of 1 consists of 19 non‐hydrogen atoms including three and a half crystallographically independent Fe and three P atoms. Fe(1) connects its symmetrical Fe(1A) through bridging oxygen forming a dimer and the dimers are connected by Fe(4) forming an infinite staircase‐like chain. Fe(2) and Fe(3) connect the infinite chains into a layer with bridging oxygen. Layers are interconnected via Fe(4) forming the six‐membered and eight‐membered channel systems.     

Preparation of a new polymer containing photoluminescent pyrazoline unit in the main chain

A novel photoluminescent polymer (PPyne) containing a 2‐pyrazoline unit in the molecular main chain was prepared (for the first time) by polycondensation between a 2‐pyrazoline monomer [an adduct of 2,6‐bis(4‐bromobenzylidene)cyclohexanone with phenylhydrazine] and 2,5‐dihexyloxy‐p‐phenylene diboric ester in the presence of Pd(PPh₃)₄. PPyne had a number‐average molecular weight of 7800 and a polydispersity index of 1.99 and showed good solubility in common organic solvents. In toluene PPyne exhibited an intrinsic viscosity [η] of 0.42 dL g^?1 at 30 °C. The polymer was photoluminescent (PL) in both the chloroform solution and the solid state; the quantum yield of PL in the solution was 40%. In the two states, PPyne gave the same ultraviolet–visible (UV–vis) peak at 368 nm and the same PL peak at 512 nm. DSC traces indicated that PPyne had a melting temperature of 168 °C, and thermogravimetric analysis revealed that the polymer had good thermal stability with a 5 wt % loss temperature of 376 °C under N₂. Electrochemical oxidation of PPyne started at about 0.5 V versus Ag/AgNO₃ and gave a peak at 0.98 V versus Ag/AgNO₃ with a color change of the film from yellow to black green. The color change was followed by UV–vis spectroscopy. The corresponding reduction peak appeared at 0.80 V versus Ag/AgNO₃. Treatment of PPyne with HCl led to dehydrogenating transformation of the polymer to a new cross‐conjugated polymer. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2686–2697, 2004     

Discotic derivatives of 6-oxoverdazyl radical

Substitution of each phenyl in 1,3,5-triphenyl-6-oxoverdazyl with three alkoxy groups induces an ordered columnar hexagonal phase (Col_h(o)) below 130°C in 1b[n], while in the alkylsulfanyl analogues 1a[n] additional periodicity along the columns was found rendering the phase a true three-dimensional columnar hexagonal phase (Col_h(3D)) below 60°C. Both series exhibit broad absorption bands in the visible region with maxima at 540 and 610 nm in series 1a[n] and at 486 and 614 nm in series 1b[n]. Unusual reversible thermochromism is observed in series 1b[n], in which the dark green isotropic phase turns red in the discotic phase. Analysis of 1a[8] revealed redox potentials E^0/+1_1/2 = +0.99 V and E^{0/ ?1}_1/2 = –0.45 V vs. saturated calomel electrode (SCE), while the potentials in the alkoxy analogue 1b[8] are shifted cathodically by 0.16 V. Photovoltaic studies of 1a[8] demonstrated hole mobility of μ_h = 1.52 × 10^?3 cm² V^?1 s^?1 in the mesophase with an activation energy E_a = 0.06 ± 0.01 eV. Magnetisation studies of 1a[8] revealed nearly ideal paramagnetic behaviour in either the solid or fluid phase above 200 K and weak antiferromagnetic interactions at low temperatures. In contrast, a noticeable drop of about 4% in μ_eff was observed during the I→Col phase transition in 1b[8], which coincide with the thermochromic effect.     

One Dimensional Coordination Polymer Constructed by1,2—Bis（4—pyridinecarboxamido）ethane and Copper（Ⅱ）

The ligand [1,2‐bis(4‐pyridinecarboxamido)ethane] (L) and the coordination polymer |[Cu(L)₂(H₂O)]‐(NO₃)₂·6H₂O|·(1) haw been synthesized and characterized by ER and ¹H NMR spectra. Their molecular structures and the packing of 1 have been determined by single‐crystal X‐ray diffraction analysis. The Cu(n) in 1 is bridged by two ligands forming an infinite one‐dimensional chain like structure and L in 1 adopts a different conformation from its free state. 1 belongs to monoclinic, space group P2₁/n, a = 1.2896(3) nm, b = 1.2552(8) nm, c = 2.2903(19) nm, β = 93.04(5)°, Z = 4, V = 3.702(4) nm³. The TG and DTG experiments showed that the uncoordinated H₂O can be removed at low temperature by heating, and it does not decompose until 250 °C.     

Effect of heating rates on TG-DTA results of aluminum nanopowders prepared by laser heating evaporation

Aluminum (Al) nanopowders with mean diameter of about 50 nm and passivated by alumina (Al₂O₃) coatings were prepared by an evaporation route: laser heating evaporation. Thermal properties of the nanopowders were investigated by simultaneous thermogravimetric-differential thermal analysis (TG-DTA) in dry oxygen environment, using a series of heating rates (5, 10, 20, 30, 50 and 90°C min⁻¹) from room temperature to 1200°C. With the heating rates rise, the onset and peak temperatures of the oxidation rise, and the conversion degree of Al to Al₂O₃ varies. However, the specific heat release keeps relatively invariant and has an average value of 18.1 kJ g⁻¹. So the specific heat release is the intrinsic characteristic of Al nanopowders, which can represent the ability of energy release.     

A Sodium Manganese Oxide Cathode by Facile Reduction for Sodium Batteries

A nonstoichiometric sodium manganese oxide (Na_xMnO_2+δ) cathode useful for sodium batteries was synthesized by an ambient‐temperature strategy that involved facile reduction of aqueous sodium permanganate in sodium iodide and subsequent heat treatment at 600 °C. Combined powder X‐ray diffraction and synchrotron X‐ray diffraction analyses confirmed the annealed sample to belong to a Na_xMnO₂ phase with a P2‐hexagonal structure. The ICP‐AES results confirmed the stoichiometry of the sample to be Na_0.53MnO_2+δ. Electron microscopy studies revealed the particle size of the electrode to be in the range of a few hundred nanometers. The Na_0.53MnO_2+δ cathode delivered an average discharge capacity of 170 mA h g^?1 with a stable plateau at 2.1 V for the initial 25 cycles versus sodium. Ex situ XANES studies confirmed the reversible intercalation of sodium into Na_0.53MnO_2+δ and suggested the accommodation of over‐stoichiometric Mn⁴⁺ ions to contribute towards the performance of the electrode.     

Synthesis and characterization of novel photosensitive polyimide based on 5‐(2,5‐dioxotetrahydrofuryl)‐3‐methyl‐3‐cyclohexene‐1,2‐dicarboxylic anhydride

A negative type photosensitive polyimide with alicyclic moiety (NPI) was synthesized from 5‐(2,5‐dioxotetrahydrofuryl)‐3‐methyl‐3‐cyclohexene‐1,2‐dicarboxylic anhydride and 4,4‐diaminobenzophenone by one‐step polymerization in m‐cresol. Properties of the polyimides were characterized and a photo‐crosslinking mechanism was investigated using DEPT ¹³C‐NMR and FT‐IR spectroscopy. The negative polyimide showed good photosensitivity on exposure to UV light from a mercury xenon lamp. The polyimide showed remarkable solubility difference after photo‐ irradiation with an exposure dose of 500 mJ/cm². The resulting negative pattern of the photo‐cured NPI exhibited 10 μm resolution. Glass transition temperature of the photo‐crosslinked polyimide was about 307°C, which increased by 10°C compared to that of the polyimide before UV exposure. Transmittance of NPI after photo‐irradiation was about 87% at 500 nm. Copyright © 2004 John Wiley & Sons, Ltd.     

The effect of calcination on morphology of phosphate coating and microstructure of sintered iron phosphated powder

Carbonyl iron powder was coated with phosphate layer using phosphating precipitation method. The phosphated powder was dried at 60 °C for 2 h in air and heat treated by calcination at 400 and 800 °C for 3 h in air. Cylindrical specimens density of ~6.5 g.cm^?3 based on iron phosphated powder calcined at 400 °C were sintered at 820, 900, 1110 °C in N₂ + 10%H₂ atmosphere and 1240 °C in vacuum for 30 min. The morphology and phase composition of the phosphate coating and sintered compacts were studied by scanning electron microscopy, atomic force microscopy (AFM) and X‐ray diffraction (XRD) analysis. Gelatinous morphology of dried phosphate coating (thickness of ~100 nm) containing nanoparticles of iron oxyhydroxides and hydrated iron phosphate was observed. From XRD, diffractogram indicated the presence of goethite α‐FeOOH, lepidocrocite γ‐FeOOH and ludlamite Fe₃(PO₄)₂.4H₂O. The calcined phosphate coating (thickness of ~ 400 nm) contained non‐homogeneous consistency of α‐Fe₂O₃ layer on iron particles, an inter‐layer of amorphous FePO₄ and Fe₃O₄ top layer. The transformation to crystalline FePO₄ structure occurred during calcination at 800 °C with the presence of α‐Fe₂O₃ forming a light top zone (rough morphology). The microstructure of compacts sintered in solid state at temperatures up to 900 °C has retained composite network character. A fundamental change in microstructure due to the liquid phase sintering occurred after sintering at temperatures of 1100 and 1240 °C. It was confirmed that the microstructure complex consists of spheroidized α‐Fe and α‐Fe₂O₃ phases surrounded by solidified liquid phase consisting various phosphate compounds. Copyright © 2013 John Wiley & Sons, Ltd.     

Oxidative Dissolution of Silver Nanoparticles by Dioxygen: A Kinetic and Mechanistic Study

We have recently reported a kinetic and mechanistic study on oxidative dissolution of silver nanoparticles (AgNPs) by H₂O₂. In the present study, the parameters that govern the dissolution of AgNPs by O₂ were revealed by using UV/Vis spectrophotometry. Under the same reaction conditions (Tris‐HOAc, pH 8.5, I=0.1 M at 25 °C) the apparent dissolution rate (k_app) of AgNPs (10±2.8 nm) by O₂ is about 100‐fold slower than that of H₂O₂. The reaction rate is first‐order with respect to [Ag⁰], [O₂], and [Tris]_T, and inverse first‐order with respect to [Ag⁺] (where [Ag⁰]=total concentration of Ag metal and [Tris]_T=total concentration of Tris). The rate constant is dependent on the size of AgNPs. No free superoxide (O₂⁻) and hydroxyl radical (⋅OH) were detected by trapping experiments. On the basis of kinetic and trapping experiments, an amine‐activated pathway for the oxidation of AgNPs by O₂ is proposed.     

The Crystal and Molecular Structure of Mercury Fulminate (Knallquecksilber)

A short survey on the fascinating history of mercury fulminate is given. The crystal structure of Hg(CNO)₂ has been determined using single crystal X‐ray diffraction. Mercury fulminate crystallizes in an orthorhombic cell, space group Cmce with a = 5.3549(2), b = 10.4585(5), c = 7.5579(4) Å and Z = 4. The distances and angles in the O‐N≡C‐Hg‐C≡N‐O molecule are Hg‐C 2.029(6) Å, C≡N 1.143(8) Å, N‐O 1.248(6) Å and C‐Hg‐C 180.0(1)°, Hg‐C≡N 169.1(5)°, C≡N‐O 179.7(6)°. Each mercury atom is surrounded by two oxygen atoms from neighbouring Hg(CNO)₂ molecules with a nonbonding distance of Hg···O 2.833(4) Å. The Hg‐C bond lengths in the linear Hg(CNO)₂ molecules are shorter than those in the tetrahedral complex [Hg(CNO)₄]^2?. This refers to a large contribution of the 6s orbital in the Hg‐C bonds of Hg(CNO)₂. The results of the X‐ray powder investigation on Hg(CNO)₂ are also reported.     

Synthesis and structure of the new gallophosphate Mu-6 containing a gallium organic complex as part of the framework

A new gallophosphate was synthesized in aqueous medium using the macrocycle 1,4,8,11-tetraazacyclotetradecane as organic species. The structure was determined by single crystal X-ray diffraction. The symmetry is monoclinic, space group C2/c, a=0.8842(3)nm, b=1.7781(2)nm, c=1.5805(3)nm, β= 92.05(3)°. The structure consists of gallophosphate chains of gallium-corner-sharing Ga₂P₂O₄ four-rings. Each chain is connected to the others via a gallium-organic complex leading to a three dimensional framework. This new gallophosphate shows low thermal stability, a complete amorphization being observed after calcination at 350°C. The results of ¹³C and ³¹P solid state nmr spectroscopy are in agreement with the structure analysis.