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Abstract: A high-contrast complementary electrochromic device based on polyaniline (PANI) tethered polyhedral oligomeric silsesquioxane (POSS) (POSS-PANI) and poly(3,4-ethylenedioxythiophene)/poly(4-styrene sulfonic acid) (PEDOT:PSS) is assembled. The electrochromic properties, cyclic voltammetry behavior and coloration efficiency of the device are studied. Due to the loosely packed structure, POSS-PANI gives rise to a significantly higher electrochromic contrast, coloration efficiency and faster switching speed than PANI. Despite its high contrast, the combination of POSS-PANI with PEDOT:PSS still shows synergy in terms of contrast enhancement, which can be attributed to the additional driving force for the diffusion of dopants into PEDOT:PSS provided by the dedoping of POSS-PANI. [Copyright &y& Elsevier]

For many advanced applications, high thermal stability above 400 °C remains as a challenge for the ordered mesoporous titania films. In this work, we attempt to increase the thermal stability of mesoporous structure in titania film crystallization via PS- b-PEO block copolymer templating route. This paper reports the highly crystallized mesoporous titania film on silicon substrate thermally stable at 600 °C. The photocatalytic activity of the titania mesoporous film was also shown to be twice of that templated by F127 for degradation of methylene blue (MB). The present results also indicate that at low crystallinity, photocatalytic activity is controlled primarily by crystal perfection rather that surface area. [ABSTRACT FROM AUTHOR]

The effects of seeds on the lead zirconate titanate (PZT) powders fabricated by sol–gel processing were studied by thermal analysis and transmission electron microscopy (TEM). A low-temperature phase transformation of 450 °C from pyrochlore (Py) to perovskite (Pe) was observed. The mechanism involved in the phase transformation was analyzed using activation energies evaluated. [Copyright &y& Elsevier]

The title nanowires are synthesized from mixtures of Ni(NO3)2, Co(NO3)2, H2C2O4, P123, EtOH, and polyethylene glycol at room temperature (10 min) followed by annealing the obtained precipitates under air at 250 °C for 3 h. [ABSTRACT FROM AUTHOR]

Preparation of Ba0.85Ca0.15Zr0.1Ti0.9O3 ( BCZT) lead-free piezoelectric ceramics with different amounts of LiF ( BCZT- xLiF) was done, and the effects of the LiF doping on the phase transition behavior and the electrical properties of the resulting ceramic were investigated. The experimental results showed that the polymorphic rhombohedral-tetragonal phase transition temperature was found shifted toward room temperature with the Li doping. The study showed that BCZT lead-free piezoelectric ceramic with improved performance properties at room temperature can be achieved by shifting the polymorphic phase transition point nearer room temperature through the addition of LiF. [ABSTRACT FROM AUTHOR]

Polyethylene–multiwalled carbon nanotube shish-kebab(PE/MWCNTSK) structures with a large aspect ratio were synthesized by solvothermalgrowth followed by recrystallization. The effects of different crystallizationtemperatures (95, 105, and 115 °C) on the polymer were investigated,and the diameter of the PE crystal lamellae on the nanotubes was foundto decrease with increasing crystallization temperature. Moreover,isothermal recrystallization of the SK structure at 115 °C producedcrystal lamellae that were uniform in diameter, with dimensions thatcould be controlled by the recrystallization time. We studied alsothe stretchable electrical properties of uniform PE/MWCNT SK structuresfilms on elastomer substrates under different strains. The electricalresistance of an SK/elastomer film was found to increase more slowly,compared to that of a film without the SK configuration, where anabrupt transition at a critical point was observed. [ABSTRACT FROM AUTHOR]

Abstract: Two types of amorphous, silica nanoparticles have been produced and used as surface assisting agents during laser desorption/ionisation time-of flight-mass spectrometry (SALDI-TOF-MS). The first is hydrophilic possessing surface aminopropyl groups and the second hydrophobic containing surface phenyl groups. Each particle type acts as a solid phase adsorbent, adsorbing analytes according to their charge and hydrophobicity. The adsorbed analytes can be directly analysed on the particles using SALDI-TOF-MS. Intrinsically magnetisable versions of the hydrophobic particles act as magnetic solid phase extraction (MSPE) materials which are used to selectively adsorb analytes within a mixture deposited onto a surface, transfer the adsorbed components using a magnetic wand and to deposit the particles at a site adjacent to that of the original mixture. Non-adsorbed components remain at the original site. The extracted and residual analytes are then directly analysed on the surface by SALDI-TOF-MS. Using fingerprints as an example of a complex biological matrix, this new approach has been used to separate polar (amino acids) and non-polar constituents (squalene and fatty acids) within latent fingerprints deposited on a surface and for their subsequent direct analysis on the surface by SALDI-TOF-MS. Alanine, ornithine, lysine and aspartic acid which were undetected or poorly detected prior to separation showed improved signal detection after separation. [Copyright &y& Elsevier]

Abstract: A N-methylpyrrolidone (NMP) assisted electrochemical deposition route has been developed to realize the synthesis of a dense α-Co(OH)2 layered structure, which is composed of nanosheets, each with a thickness of 10nm. The capacitive characteristics of the as-obtained α-Co(OH)2 are investigated by means of cyclic voltammetry (CV), charge/discharge characterization, and electrochemical impedance spectroscopy (EIS), in 1M KOH electrolyte. The results indicate that α-Co(OH)2 prepared in the presence of 20vol.% NMP has denser and thin layered structure which promotes an increased surface area and a shortened ion diffusion path. The as-prepared α-Co(OH)2 shows better electrochemical performance with specific capacitance of 651Fg−1 in a potential range of −0.1 to 0.45V. These findings suggest that the surfactant-assisted electrochemical deposition is a promising process for building densely packed material systems with enhanced properties, for application in supercapacitors. [Copyright &y& Elsevier]

Abstract: To investigate the properties of (K,Na)NbO3-based lead-free piezoelectric films at the morphotropic phase boundary composition, we fabricated epitaxial [(K0.5Na0.5)0.97Li0.03] (Nb0.8Ta0.2)O3 films on (001), (110) and (111)-oriented single crystal SrTiO3 substrates by pulsed laser deposition. The structure and electrical properties of the films were studied. Dielectric constants of 540, 390 and 300 and remnant polarizations of 4.00, 1.05, and 0.35μC/cm2 were observed for the (001), (110) and (111) oriented films, respectively. [ABSTRACT FROM AUTHOR]

Substituting of Ru with Sn and Sb in the phase RuZn3led to two new zinc-rich ternary compounds: Ru4Sn2.9Zn11.6(SnRZ: Monoclinic, C2/m, Pearson symbol oC46–δ, a= 6.8011(14), b= 7.9760(16), c= 11.083(2) Å, β= 97.56(3)°, Z= 2) and Ru3.0Sb0.97Zn11.0(SbRZ: Orthorhombic, Cmcm, Pearson symbol oC60, a= 7.8936(16), b= 6.8347(14), c= 16.904(3) Å, Z= 4). The structures of SnRZand SbRZare composed of four identical atomic layers but with different stacking sequences. They exhibit structural units of either three or two interpenetrating icosahedra fusing to form chains along the caxis. Their aand blattice parameters are alike—interchanged in the chosen conventional setting—while the cparameters are related by cSbRZ/2 × (1 τ) 2cSnRZwith τ= (1 √5)/2 being the golden mean (known as τ-inflated phases). Both two compounds exhibit diamagnetic properties, and SnRZand SbRZcongruently melt at 1296 K and 1233 K, respectively. Temperature-dependent resistivities reveal metallic behavior. The negative Seebeck coefficients indicate transport processes are dominated by electrons as carriers. [ABSTRACT FROM AUTHOR]

Abstract: Electrophoretic deposition (EPD) was applied in coating hydrothermally synthesized crystalline tungsten oxide (WO3) nanorods onto ITO glass for electrochromic application. Nanorods suspension of 10mg/cm3 was used in the EPD with optimum electric field of 5–6V/cm. Saturation in WO3 deposited amount at electric field >7V/cm was observed during constant voltage EPD. This could be attributed to the oxide layer shielding effect on the electric field induced electrophoresis. Constant current EPD from 0.2mA/cm2 to 1.4mA/cm2 was also performed for the WO3 nanorods. The deposited amount of nanorods was found to be proportional to the current density from 0.2mA/cm2 to 0.8mA/cm2 under constant deposition duration. However, the deposited amount decreased at current density >0.8mA/cm2. This could be due to the high deposition rate that resulted in poor adhesion and hence nanorods peel off during the substrate removal. It was noted that the EPD of nanorods followed a linear relationship in I vs. t −1/2 plot according to Cottrell equation, which implied that the reaction was a diffusion controlled process. The EPD coated substrate was tested in 1M LiClO4/propylene carbonate (PC) electrolyte for electrochromic studies. The porous WO3 nanorods layer exhibited optical modulation ΔT 700nm of 40%, moderate coloration time of 28.8s and improved bleaching time of 4.5s, which could be due to the porous oxide layer with large surface area that facilitates the ion insertion/extraction and the electrolyte penetration in the oxide layer shortens the ionic diffusion length of Li. [Copyright &y& Elsevier]

In this work, a combined process, called centrifugal gel casting (CGC), was proposed for the fabrication of homogenous and reliable monolithic and composite ceramics starting from submicrometer-sized powders. This method exploits the advantages of both conventional gel casting (GC) and centrifugal slip casting (CSC), while overcoming the limitations associated with the two methods. Via this process, a relatively low centrifugal force is applied to form a highly concentrated slurry in the mold cavity, which is then followed by in situ polymerization of slurry during gelation. In this work, concentrated alumina slurries with different solid contents from 45 to 65 vol% were consolidated by the three forming methods mentioned above. Various properties of green and fired products were measured and compared. Shorter processing time, lower centrifugal force, higher green strength, and minimal segregation are observed to be the characteristics of CGC in comparison with CSC. In situ elimination of bubbles with no need for degassing and the ability to remove heterogeneities, on top of high reliability and the potential to process higher viscosity slurries, are the main advantages of this method over the conventional GC. [ABSTRACT FROM AUTHOR]

Abstract: In this paper we report a high-contrast complementary electrochromic device based on polyaniline-tethered polyhedral oligomeric silsesquioxane (POSS-PANI) and tungsten oxide (WO3). The electrochromic properties, cyclic voltammetry behavior and coloration efficiency of the device are studied. Due to the loosely packed structure of POSS-PANI, it possesses more accessible doping sites and hence gives rise to a significantly higher electrochromic contrast than polyaniline (PANI). Furthermore, the replacement of PANI with POSS-PANI as the complementary layer for WO3 leads to an enhanced complementary effect, for which the underneath mechanism is also discussed. [Copyright &y& Elsevier]

Abstract: A new series of electrochromic polymers are synthesized via oxidative emulsion copolymerization of hexa(4-aminophenoxy)cyclotriphosphazene (HACP) and aniline in the presence of dodecylbenzene sulfonic acid. The structures of the copolymers are characterized using nuclear magnetic resonance spectroscopy, size exclusion chromatography, wide angle X-ray diffraction, scanning and transmission electron microscopy. The results reveal that the copolymer containing 4.0mol % HACP (4.0% HACP–PANI) possesses a large number of nanometer-sized crystallites due to the unique molecular architecture of HACP–PANI. Spectro-electrochemical studies show that 4.0% HACP–PANI exhibits a significant enhancement in electrochromic contrast as compared with homopolyaniline (PANI). The contrast enhancement can be attributed to the easier diffusion of cations into nanometer-sized crystals, which is evidenced by a significant increase in ionic conductivity. At lower HACP concentrations, the copolymers induce the crystallization of linear PANI as substantial amounts of PANI may form during the polymerization, resulting in increased crystal size, and hence low electrochromic contrasts. [Copyright &y& Elsevier]

Abstract: Uniform single-crystalline tungsten oxide (WO3) nanosheets have been synthesized in a large-scale with W powders as starting material. The results from the thermal stability measurements show that the as-synthesized WO3 nanosheets are anhydrous. Their thickness and length are ∼80 and ∼500nm, respectively. They exhibit blue luminescence emissions at ∼431, 486 and 497nm, UV emissions at ∼362 and 398nm. The blue emissions are resulted from the band–band indirect transition and the UV emissions should be attributed to the defect states of WO3. The growth mechanism of the two-dimensional WO3 nanosheets is discussed. [Copyright &y& Elsevier]

Abstract: The response of porous Al2O3 to nanoindentation was investigated at microscopic scales (nm–μm) and under ultra-low loads from 5 to 90mN with special attention paid to the dependence of the load–depth behaviour to sample porosity. It was found that the load–depth curves manifest local responses typical of the various porous structures investigated. This is particularly clear for the residual deformation after load removal. Similarly, the limited mean pressure of the sample containing small grains and interconnected pores is consistent with its porous structure. By comparison, the samples with larger grain size and various porous structures exhibit higher pressures and smaller residual deformations that can be attributed to the mechanical response of the solid phase. [Copyright &y& Elsevier]

Abstract: Mesoporous SnO2/SnO2–SiO2 with disordered pores and high thermal stability up to 600°C were fabricated using hydrothermal treatment with/without impurity oxide (SiO2) doping. Neutral surfactant (tetradecylamine, TDA) was selected as the structure directing agent based on a sol–gel-derived process. The results showed that with careful control of the synthesis condition, mesoporous SnO2–SiO2 with small SnO2 nanocrystallites (∼25Å), large specific surface area (211–340m2/g), and pore volume (0.23–0.3cm3/g) could be obtained after the removal of template at temperatures of 400–600°C. The effects of synthesis parameters such as aging time, hydrothermal treatment, Si/Sn molar ratio and calcination temperature were characterized by thermogravimetric analysis, wide/small-angle X-ray scattering (SAXS), HRTEM, and BET gas (N2) adsorption/desorption measurements. [Copyright &y& Elsevier]

Abstract: The first example of mesostructured tin(IV) oxide that shows very large specific surface area and high thermal stability has been prepared using neutral surfactant (tetradecylamine) as template and tetraethylorthosilicate (TEOS) as crystal growth inhibitor. The one-pot synthesis route reported here is facile and effective to produce highly thermal stable mesoporous (average BJH pore size ∼30 Å) tin oxide with small crystals (<25 Å), narrow pore size distribution (PSD), large pore volume (0.23–0.3 cm3/g), and very large specific surface areas (211–339 m2/g) upon the removal of organic template at temperatures from 400 to 600 °C. The results show that collaborative effects from surfactant template and crystal growth inhibitor (TEOS) are vital in obtaining tin oxide with high mesostructural quality. [Copyright &y& Elsevier]

Ultrafine MnO2nanowires with sub-10 nm diameters have been synthesized by a simple process of hydrothermal treatment with subsequent calcinations to form networks that exhibit an enhanced specific capacitance (279 F g−1at 1 A g−1), high rate capability (54.5% retention at 20 A g−1) and good cycling stability (1.7% loss after 1000 cycles). [ABSTRACT FROM AUTHOR]

Abstract: Nanosized neodymium doped yttrium aluminum garnet (Nd:YAG) powders have been synthesized by a modified sol–gel combustion method by using nitrate salts as starting materials. Phase evolution, morphology, and microstructure of the synthesized powders were investigated. Solvent plays an important role in the phase formation of the precursor. Crystallized Nd:YAG powders can be directly obtained at as low as 800°C without the formation of any intermediate phase. The crystallization kinetics of amorphous YAG precursor was studied by variable heating rate of DTA. The activation energy for crystallization of the YAG by modified sol–gel combustion is 361.7kJmol−1, which is much lower than 480.6kJmol−1 determined from that by general sol–gel combustion. The as-prepared powders are well crystallized and soft aggregated with average crystalline size about 60nm at 1200°C. Good luminescent property is observed in the Nd:YAG nanopowders and the emission intensity increased with increasing the calcination temperatures. [Copyright &y& Elsevier]

Highly transparent 1 at.% Er: YAG ceramics was fabricated by a reactive sintering method under vacuum. The optical properties, the microstructure and the laser performance of the Er: YAG ceramics were investigated. The average grain size of the Er: YAG ceramics was 7~8 μm. The in-line transmittances of the Er: YAG ceramics at the wavelength of 1800 and 400 nm were about 84.6% and 82.4%, respectively. The absorption coefficient of the Er: YAG ceramics was 1.29 cm−1. The grain boundaries were very clean and no secondary phase was observed. When end-pumped by an Er, Yb-fiber laser at 1532 nm, a maximum output power of 13.8 W lasing at the wavelength of 1645 nm was obtained with a slope efficiency of 54.5%. [ABSTRACT FROM AUTHOR]

Abstract: In this article, we report a novel fullerene–polyaniline emeraldine base (C60–PANI-EB) hybrid synthesized through covalent bonding of polyaniline (PANI) onto para-phenylenediamine (PPD)-functionalized fullerene and its capacity properties. C60–PANI-EB exhibits a unique coral-like porous morphology with PANI particles interconnected by nanofibers. In comparison with polyaniline emeraldine base (PANI-EB), C60–PANI-EB shows significantly higher specific capacitance, specific power and specific energy, and better cycling stability. The specific capacitance of C60–PANI-EB and PANI-EB are 776Fg−1 and 492Fg−1 at current density of 1mAcm−2, respectively. The specific capacitance of C60–PANI-EB has 37% enhancement over that of PANI-EB even at high current density of 100mAcm−2. The specific energy of C60–PANI-EB is 64Whkg−1 at 1mAcm−2 and the specific power is 36,595Wkg−1 at current density of 100mAcm−2. The greatly enhanced capacity performance can be attributed to the increased ionic conductivity induced by the loose molecular packing structure and porous morphology as well as the increased electrical conductivity caused by the coral-like interconnected morphology and the strong electron-withdrawing function of the fullerene through its covalent bonding to PANI. [Copyright &y& Elsevier]

Abstract: The ability of two mass spectrometric methods, surface-assisted laser desorption/ionization-time of flight-mass spectrometry (SALDI-TOF-MS) and direct analysis in real time (DART-MS), to detect the presence of seven common explosives (six nitro-organic- and one peroxide-type) in spiked latent fingermarks has been examined. It was found that each explosive could be detected with nanogram sensitivity for marks resulting from direct finger contact with a glass probe by DART-MS or onto stainless steel target plates using SALDI-TOF-MS for marks pre-dusted with one type of commercial black magnetic powder. These explosives also could be detected in latent marks lifted from six common surfaces (paper, plastic bag, metal drinks can, wood laminate, adhesive tape and white ceramic tile) whereas no explosive could be detected in equivalent pre-dusted marks on the surface of a commercial lifting tape by the DART-MS method due to high background interference from the tape material. The presence of TNT and Tetryl could be detected in pre-dusted latent fingermarks on a commercial lifting tape for up to 29 days sealed and stored under ambient conditions. [Copyright &y& Elsevier]

We report a simple and highly efficient method for creating graphene nanostructures with gaps that can be controlled on the sub-10 nm length scale by utilizing etch masks comprised of electrochemically synthesized multisegmented metal nanowires. This method involves depositing striped nanowires with Au and Ni segments on a graphene-coated substrate, chemically etching the Ni segments, and using a reactive ion etch to remove the graphene not protected by the remaining Au segments. Graphene nanoribbons with gaps as small as 6 nm are fabricated and characterized with atomic force microscopy, scanning electron microscopy, and Raman spectroscopy. The high level of control afforded by electrochemical synthesis of the nanowires allows us to specify the dimensions of the nanoribbon, as well as the number, location, and size of nanogaps within the nanoribbon. In addition, the generality of this technique is demonstrated by creating silicon nanostructures with nanogaps. [ABSTRACT FROM AUTHOR]

Abstract: Si nanowires in graphene papers were successfully prepared by supercritical fluid–liquid–solid (SFLS) process, which showed high specific capacities and charge–discharge cycling stability as anode materials for Li-ion storage. The enhancement on capacity and cycling stability of the Si/graphene composite nanostructures was attributed to the presence of graphene papers in the hybrid samples that served as a highly conductive framework and absorption of volume changes of Si nanowires during the lithiation/delithiation process. This Si/graphene electrodes maintained reversible capacities of 1400mAhg−1 for the 30th cycle at a current density of 420mAg−1, which is much better as compared to that of pure Si nanowires. [Copyright &y& Elsevier]

Abstract: In this article, fullerene covalently bonded with multiple polyaniline (PANI) arms (C60-PANI) was readily synthesized via copolymerization of aniline with p-phenylenediamine (PPD) functionalized fullerene in the presence of poly(styrene sulfonate) (PSS) dopant agent in an aqueous medium to produce a water-processable electrochromic material. The PSS-doped C60-PANI (C60-PANI:PSS) film possesses finer morphology in comparison with PSS-doped PANI (PANI:PSS) film. Owing to the electron acceptor characteristic and high conductivity of fullerene as well as the loose morphology of C60-PANI:PSS, the synthesized hybrids exhibit simultaneously enhanced electrical and ionic conductivities, resulting in improvement of electrochromic performance. In particular, the electrochromic device with C60-PANI:PSS as the active layer shows significant enhancement in optical contrast and electrochemical stability over the PANI:PSS-based device. [Copyright &y& Elsevier]

Abstract: Poly(styrene sulfonate) (PSS) tethered polyhedral oligomeric silsesquioxane (POSS-PSS) was synthesized and used as star-like dopant for the preparation of core–shell polyaniline/POSS-PSS (PANI/POSS-PSS) nanoparticles. The prepared aqueous emulsion shows good processibility and high stability. The electrochemical characteristics and electrochromic properties of PANI/POSS-PSS were studied. In comparison with polyaniline (PANI) doped with linear PSS dopant, the star-like POSS-PSS dopant renders PANI/POSS-PSS-based electrochromic device higher optical contrast and faster switching speed owing to the faster ion transportation resulting from the porous morphology of PANI/POSS-PSS. [Copyright &y& Elsevier]

Microporous metal-organic frameworks (MOFs) that display permanent porosity show great promise for a myriad of purposes. The potential applications of MOFs can be developed further and extended by encapsulating various functional species (for example, nanoparticles) within the frameworks. However, despite increasing numbers of reports of nanoparticle/MOF composites, simultaneously to control the size, composition, dispersed nature, spatial distribution and confinement of the incorporated nanoparticles within MOF matrices remains a significant challenge. Here, we report a controlled encapsulation strategy that enables surfactant-capped nanostructured objects of various sizes, shapes and compositions to be enshrouded by a zeolitic imidazolate framework (ZIF-8). The incorporated nanoparticles are well dispersed and fully confined within the ZIF-8 crystals. This strategy also allows the controlled incorporation of multiple nanoparticles within each ZIF-8 crystallite. The as-prepared nanoparticle/ZIF-8 composites exhibit active (catalytic, magnetic and optical) properties that derive from the nanoparticles as well as molecular sieving and orientation effects that originate from the framework material. [ABSTRACT FROM AUTHOR]

Abstract: Highly transparent Er:YAG ceramics with different Er doping concentrations were fabricated by a reactive sintering method under vacuum. The optical properties and the microstructures of the Er:YAG ceramics were investigated. For 3mm thickness samples, the in-line transmittances of the as-fabricated Er:YAG ceramics at the wavelength of 1100nm and 400nm were about 84% and 82%, respectively. The micrograph of the Er:YAG transparent ceramics exhibited a pore-free structure and the average grain size was about 10μm. The grain boundary of the ceramics was clean and no secondary phase was detected. The absorption and emission spectra, the fluorescence decay traces of the Er:YAG ceramics were measured and discussed. The ceramics obtained may have potential use for eye-safe solid-state lasers partly replacing Er:YAG single crystals. [Copyright &y& Elsevier]

Abstract: Nd:YAG transparent ceramics were fabricated by a reactive sintering method under vacuum using SiO2, MgO and compound additives (SiO2 and MgO) as sintering aids. The effects of SiO2 and MgO on the microstructure and sintering process of Nd:YAG ceramics were studied. High quality Nd:YAG ceramics with compound sintering aids obtained by vacuum sintering at 1780°C are composed of grains of the size ∼10μm, and their transmittance is 82% at 400nm. It was found the absorption coefficient of 1.0mol% Nd:YAG ceramic was 8.6cm−1 at 808nm and its absorption cross section was calculated to be 6.26×10−20 cm2. [Copyright &y& Elsevier]

Abstract: High optical quality transparent Yb:YAG laser ceramics have been successfully fabricated by a vacuum reactive sintering method. Commercial Al2O3 powder and co-precipitated Y2O3 and Yb2O3 powders were used as the raw materials. In-line transmittances at 1300nm and 400nm were measured to be 83.6% and 81.8% respectively for a 3mm thick mirror polished Yb:YAG ceramics sample. Continuous wave (CW) lasing at the wavelength of 1030nm was achieved when pumped by a 940nm fiber coupled laser diode. A slope efficiency as high as 62.7% was obtained. [Copyright &y& Elsevier]

Abstract: High quality transparent yttrium aluminum garnet (YAG) ceramics with an average grain size of about 12μm have been fabricated by a solid state reactive sintering method. Plasma resistance property of the fabricated YAG ceramics was studied and compared with that of the Y2O3 ceramics, silicate glass and quartz. The YAG ceramics showed an excellent plasma resistance as well as Y2O3 ceramics. After etching in F-plasma for 6h, the eroded depth of YAG ceramics was about 100nm. The plasma resistance of YAG ceramics was far better than that of silicate glass and quartz. [Copyright &y& Elsevier]

Abstract: Lead-free piezoelectric 0.94(K0.5Na0.5)NbO3–0.06LiNbO3 (0.94KNN–0.06LN) ceramics were prepared by solid state reaction process modified by introducing polyvinylpyrrolidone (PVP) of different molecular weights in the starting raw materials. The chemical interaction between the metal cations and the PVP, particularly through the N in PVP, was observed. The effects of PVP for suppressing the loss of alkali ions, promoting the perovskite phase formation, and improving the piezoelectric properties were characterized and discussed. With molecular weight ranging from 55K to 1300K, PVP with lower molecular weight exhibited more significant effect. This study showed that introducing PVP in the starting raw materials may be an effective method for obtaining stoichiometric KNN–LN and other ceramics with volatile alkali ions. [Copyright &y& Elsevier]

High optical quality holmium doped yttrium aluminum garnet ( Ho:YAG) transparent ceramics that contained 0.5-2.0 at.% holmium additives were fabricated by a reactive sintering method under vacuum. Fully dense Ho:YAG ceramics with the average grain size of ~10 μm were obtained after vacuum sintered at 1780°C for 8 h. The in-line transmittances in the visible and infrared region are higher than 82% and 84%. The absorption coefficients of the 0.8, 1.0, 1.5, and 2.0 at.% Ho:YAG ceramics at 1907 nm was calculated to be 0.72, 0.89, 1.32, and 1.78 cm−1, respectively. The absorption cross-section of Ho:YAG ceramic was 0.645 × 10−20 cm2. The 1.5 and 2.0 at.% Ho:YAG ceramic slabs were in-band pumped by a Tm:fiber laser at 1907 nm. A maximum output power of 20.6 W at 2097 nm was obtained with a corresponding slope efficiency of 60.9%. [ABSTRACT FROM AUTHOR]

Well-dispersed Nd:YO powders with uniform particle size of about 60 nm were synthesized from freeze-dried precursors. Highly transparent 2 at.% Nd:YAG ceramics were fabricated from the as-synthesized Nd:YO powders and commercial AlO powders by vacuum sintering at 1,750 °C for 5 h. Phase evolution, microstructures, and spectroscopic properties of the Nd:YAG transparent ceramics were investigated. Freeze-drying played an important role in the synthesis of high-quality Nd:YO nanosized powders, which were essential for the fabrication of highly transparent Nd:YAG ceramics. Optical transmittance of a 3-mm thick sample reached 82% in the wavelength range of 200-900 nm. 5.23 W output power was obtained with 14.3 W diode laser pumping, giving a slope efficiency of 36.5%. [ABSTRACT FROM AUTHOR]

Abstract: In this work, the effects of thermal annealing on the structures and properties of an ionic liquid (IL) of 1-butyl-3-methylimidazolium hexafluorophosphate-loaded supercritical carbon dioxide-treated electrospun poly(vinylidene fluoride)-hexafluoropropylene (PVDF-HFP) membrane were studied and compared with a corresponding IL/PVDF-HFP gel membrane. The results show that although the annealing causes slight distortion of the nanofibers as well as some small changes in crystallinity and crystal size, the nanofibrous and microporous morphology of the membrane is not altered and hence the membrane can retain its high optical transparency and ionic conductivity after the annealing, whereas the gel exhibits significantly reduced optical transmittance and ionic conductivity owing to annealing-induced phase separation. The IL/PVDF-HFP electrospun membranes before and after annealing were used as the electrolyte layer in electrochromic devices, respectively. The device with the annealed IL/PVDF-HFP electrospun membrane shows no performance deterioration, demonstrating the potential of such thermally stable electrolyte for electrochromic devices used in harsh environments. [Copyright &y& Elsevier]

This article examines the use of doped amorphous silica nanoparticles for surface-assisted laser desorption/ionisation-time of flight-mass spectrometry (SALDI-TOF-MS) of hydrophilic and hydrophobic compounds. A range of particles with surface aliphatic carboxylic, aminophenyl, phenyl or aminopropyl groups have been produced and these have been doped with carbon black, polyaniline or graphite. The effects of surface groups and dopants on the laser desorption/ionisation process were studied. The key factor in effective LDI was the presence of carbon black dopant carrying carboxyphenyl or phenyl residues for positive and negative ion formation. The second key factor was the presence of hydrophilic surface functional groups for hydrophilic amino acid analytes for their detection in positive or negative mode as protonated or de-protonated species respectively whereas hydrophobic surfaces were need for ionisation viacationisation for the hydrophobic analyte squalene. The mechanism for LDI of these particles appears to involve initial adsorption of the analyte onto the surface of the particle, formation of primary ions viaadsorption of laser UV irradiation by carboxyphenyl residues attached to the carbon black network which act in an equivalent way to the matrix in matrix-assisted LDI. This is followed by reaction of the primary ions with neighbouring adsorbed analyte molecules. The latter are then released possibly viathermal desorption following proton donation or acceptance from/to viasurface residues such carboxylate groups associated with the carbon black within the dopant. Alternatively in the absence of such proton donor/acceptor residues as with hydrophobic particles, the primary ions are released from the particles during desorption and form cation adducts as sodiated and potassiated species in the gas phase above the surface. [ABSTRACT FROM AUTHOR]

Premixed atmospheric flat flame deposition is a large-scale composite fabrication method that combined the advantages of flame synthesis and thermal evaporation. The technology has been successfully developed to sythesize SnO2 nanowires. The results showed that the as-prepared SnO2 nanowires with special tips are uniform single crystals, growing along [001] direction. Meanwhile, the growth mechanism of the present novel structure, which is a combination of both a vapor-solid (VS) growth mechanism and a particle formation mechanism in a flame without any catalyst, is also proposed. Furthermore, the optical property is investigated by photoluminescence (PL) spectroscopy, indicating that such SnO2 nanowires exhibit a much stronger emission peak at 620 nm. More importantly, this approach also provides a new pathway for sequentially engineering one-dimensional nanomaterials. [ABSTRACT FROM AUTHOR]

Abstract: Neodymium doped YAG transparent ceramics were fabricated by vacuum reactive sintering method using commercial α-Al2O3, Y2O3 and Nd2O3 powders as the starting materials with both tetraethyl orthosilicate (TEOS) and MgO as sintering aids. The morphologies and microstructure of the powders and Nd:YAG transparent ceramics were investigated. Fully dense Nd:YAG ceramics with average grain size of ∼10μm were obtained by vacuum sintering at 1780°C for 8h. No pores and grain-boundary phases were observed. The in-line transmittance of the ceramic was 83.8% at 1064nm. [Copyright &y& Elsevier]

A single-step fabrication of ZnSb nanostructures using template-free electrochemical deposition was developed. Results have indicated that ZnSb nanoflakes, nanowires, or nanoparticles with controlled composition could be obtained by adjusting the precursor concentration, applied voltage, and substrate type. The ZnSb nanostructures deposited on Cu foils were directly used as Li-ion battery anodes without the addition of any binder. Electrochemical analyses revealed that the interconnected ZnSb nanoflakes depicted high discharge capacities and a stable performance, which were better than that of ZnSb nanowires and nanoparticles. With an initial discharge capacity of 735 mA h/g and an initial Columbic efficiency of 85%, the ZnSb nanoflakes maintained a discharge capacity of 500 mA h/g with a Coulombic efficiency of 98% after 70 cycles at a current density of 100 mA/g (0.18 C). The ZnSb nanowires and nanoparticles showed a capacity of 190 and 40 mA h/g, respectively, after 70 cycles at the same current density. The improved performance of the interconnected ZnSb nanoflakes is attributed to their open structure, with a large surface area and small crystal grains, to facilitate the diffusion of Li ions and to buffer the large volume swings during the lithium intercalation process. A single-step fabrication of ZnSb nanoflakes, nanowires, or nanoparticles with controlled composition and phase, using template-free electrochemical deposition, was developed. The binder-free ZnSb nanoflake electrodes applied in Li-ion battery cells depicted promising lithium storage performance. [ABSTRACT FROM AUTHOR]

Abstract: Spherical monodispersed, submicron-sized Y2O3 powder was prepared via a homogeneous precipitation method using nitrate and urea as raw materials. The structure, phase evolution and morphology of Y2O3 precursor and the calcined powder were studied by FTIR, TG/DTA, XRD and SEM methods. The sphere size of the precursor was about 250nm and that of Y2O3 powder calcined at 800°C for 2h was about 200–210nm. With the spherical Y2O3 powder and a commercial Al2O3 ultrafine powder, high transparent YAG ceramics was fabricated by vacuum sintering at 1780°C for 6h through a solid-state reaction method. The in-line transmittances of the as-fabricated YAG ceramics at the wavelength of 1064nm and 400nm were 82.8% and 79.5%, respectively, which were much higher than that of the YAG ceramics with a commercial Y2O3 powder and a commercial Al2O3 ultrafine powder directly. The superior properties are attributed to the good morphology, dispersibility and uniform grain size of the as-prepared spherical Y2O3 powder, which matches that of the commercial Al2O3 powder. [ABSTRACT FROM AUTHOR]

Abstract: The effect of sulfur poisoning on the activity and performance of Ni/Y2O3–ZrO2 (Ni/YSZ) and Ni/Gd2O3–CeO2 (Ni/GDC) cermet anodes of solid oxide fuel cells has been examined by polarization and electrochemical impedance spectroscopy (EIS) measurements at 800 °C. The anodes are alternately polarized in pure H2 and H2S-containing H2 fuels with H2S concentration gradually increased from 5 ppm to 700 ppm at 200 mA cm−2 for 2 h. The results show that the anode potential of Ni/YSZ electrodes measured in pure H2 decreases from 0.61 V to 0.34 V after exposure to H2S-containing H2 fuels with H2S concentration increased from 5 to 700 ppm. On the other hand, the anode potential of Ni/GDC electrodes measured in pure H2 decreases from 0.78 V to 0.72 V under identical test conditions. The degradation in performance for the hydrogen oxidation in H2S-containing H2 fuels is substantially smaller on Ni/GDC anodes, as compared to that on Ni/YSZ anodes. Similar trend is also observed for the change of the electrode polarization resistance for the hydrogen oxidation reaction on the Ni/YSZ and Ni/GDC anodes after exposure to H2S-containing H2 fuels. The SEM results indicate the structure modification of Ni/YSZ anodes only occurs on Ni particles, and in the case of Ni/GDC anodes, structural modification on both Ni and GDC phases occurs. The mixed ionic and electronic conductivity of GDC phase could be the primary reason for the high sulfur tolerance of the Ni/GDC cermet anodes. [Copyright &y& Elsevier]

To study the effect of different surface structures on resultant mechanical and rheological properties, nano-CaCO3 particles were treated with isopropyl tri-stearyl titanate (H928), isopropyl tri-(dodecylbenz-enesulfonyl) titanate (JN198), and isopropyl tri-(dioctylpyrophosphato) titanate (JN114). Scanning electron microscopy (SEM) and dynamic mechanic analysis (DMA), carried out to characterize the effective interfacial interaction between the nano-CaCO3 particles and a poly(vinyl chloride) (PVC) matrix, indicated that JN114 treated nano-CaCO3 particles had the strongest interfacial interaction with a PVC matrix, while H928 treated nano-CaCO3 had the weakest. The rheological and mechanical properties of PVC/nano-CaCO3 composites were investigated as a function of surface structure and filler volume fraction. The tensile yield stress and elongation at break decreased with the increasing of calcium carbonate content while tensile modulus increased. PVC filled with JN114 treated nano-CaCO3 had the highest tensile modulus and tensile yield stress, while those filled with H928 treated nano-CaCO3 had the highest elongation at break at the same filler content. The impact strength of PVC/nano-CaCO3 composites increased with the increasing of CaCO3 content, and PVC composites filled with JN198 treated nano-CaCO3 particle had a higher impact strength than those with JN114 or H928 treated, with the value reaching 23.9 ± 0.7 kJ/m2 at 11 vol% CaCO3, four times as high as that of pure PVC. Rheological properties indicated that a suitable interfacial interaction and a good dispersion of inorganic filler in a PVC matrix could reduce the viscosity of PVC/nano-CaCO3 composites. The interfacial interaction was quantitatively characterized by semiempirical parameters calculated from the tensile strength of PVC/nano-CaCO3 composites to confirm the results from the SEM and DMA experiments. [ABSTRACT FROM AUTHOR]

Substituting of Ru with Sn and Sb in the phase RuZn3led to two new zinc-rich ternary compounds: Ru4Sn2.9Zn11.6(SnRZ: Monoclinic, C2/m, Pearson symbol oC46–δ, a= 6.8011(14), b= 7.9760(16), c= 11.083(2) Å, β= 97.56(3)°, Z= 2) and Ru3.0Sb0.97Zn11.0(SbRZ: Orthorhombic, Cmcm, Pearson symbol oC60, a= 7.8936(16), b= 6.8347(14), c= 16.904(3) Å, Z= 4). The structures of SnRZand SbRZare composed of four identical atomic layers but with different stacking sequences. They exhibit structural units of either three or two interpenetrating icosahedra fusing to form chains along the caxis. Their aand blattice parameters are alike—interchanged in the chosen conventional setting—while the cparameters are related by cSbRZ/2 × (1 + τ) 2cSnRZwith τ= (1 + √5)/2 being the golden mean (known as τ-inflated phases). Both two compounds exhibit diamagnetic properties, and SnRZand SbRZcongruently melt at 1296 K and 1233 K, respectively. Temperature-dependent resistivities reveal metallic behavior. The negative Seebeck coefficients indicate transport processes are dominated by electrons as carriers. [ABSTRACT FROM AUTHOR]

Abstract: B-site modification lead strontium zirconate titanate Pb0.4Sr0.6Zr x Ti1− x O3 (PSZT, x =0–0.7) thin films were prepared on Pt/TiO2/SiO2/Si substrates by a sol–gel method. The XRD results indicate that paraelectric PSZT thin films at room temperature are obtained as x approaches 0.2. The temperature-dependent dielectric and hysteresis loop measurements reveal that the thin films have diffuse phase transition characteristics and relaxor-like behavior with nano-polar regions in the paraelectric films at room temperature. The Curie temperature of the PSZT thin films varies with the Zr contents, exhibiting a complex trend. This can be attributed to two competitive factors: higher mobility of Ti4+ than Zr4+ and smaller open space left for the displacement of Ti ions with the increase of Zr content. The further increase of the Zr contents leads to the simultaneous decrease of dielectric constant, dielectric loss and tunability. PSZT (x =0.4) thin film shows the largest figure of merit of 24.3 with a moderate tunability of 55.8% and a dielectric loss of 0.023. This suggests that B-site ions have different roles in modifying the electrically tunable performance of PSZT thin films for tunable microwave device applications. [Copyright &y& Elsevier]

A modified sol–gel processing has been developed by using polyvinylpyrrolidone (PVP) as modifier and lead nitrate as lead source to synthesize (1− x)Pb(Mg1/3,Nb2/3)O3− xPbTiO3 (PMN–PT) thin films with x=0.23–0.43. The composition distribution and morphology of the gel particles in the PMN–PT solutions have been investigated. It shows that PVP addition results in spatial separation between Pb and Nb ions in the gel particles, leading to the perovskite crystallization via a columbite-like route in the resultant PMN–PT thin films. Pyrochlore phase is circumvented and perovskite phase can directly crystallize from amorphous films at the temperature as low as 460°C, while in the non-PVP films, B-site rich pyrochlore phase (Pb1.83Nb1.71Mg0.29O6.39) is always formed in the temperature range used (460°–650°C). [ABSTRACT FROM AUTHOR]

Abstract: A novel photocatalyst ZnTiO3 powder was prepared by a modified alcoholysis method, using ethylene glycol as reagent/solvent and acetylacetone as stabilizer. A series of analytical techniques were used to characterize the crystallinity, composition, bandgap, morphology, specific surface area and grain size of ZnTiO3 powders. The relationship between the physicochemical property and the photocatalytic activity was deeply investigated, too. It is found that the photocatalytic activity is dependent on the phase of catalysts. The product of ZnTiO3 with pure hexagonal-phase calcined at 800°C for 3h exhibits the maximum photocatalytic performance in the photochemical degradation of the azo dye methyl violet under solar light irradiation. The processing parameters such as the concentration of catalysts and the pH value also play an important role in tuning the photocatalytic activity. The optimal concentration and pH value of the pure hexagonal-phase ZnTiO3 is around 4g/L and 8 in a 10mg/L dye-aqueous solution, respectively. [Copyright &y& Elsevier]

Abstract: Yttria nanopowders have been synthesized by carbonate precipitation process. The thermal decomposition behavior of the carbonate precipitate, crystal phase, microstructure and sinterability of the powders were examined. The precipitate precursor was decomposed completely at 700°C and then crystallized well into cubic yttria phase. Our results suggested that the most favorable calcination temperature was 1100°C for obtaining good dispersion, high-reactive yttria nanopowders. The nanopowders were almost spherical and had weak agglomeration and narrow particle size distribution with a mean grain size of about 80nm. Using these yttria nanopowders, nearly full dense yttria ceramic with ∼99.2% of theoretical density was obtained at 1600°C for 2h without any additives. [Copyright &y& Elsevier]