Organic-free synthesis of nanostructured SnO2 thin films by chemical solution deposition

Novel synthetic approach for preparation of single phase porous SnO2 thin films with controllable grain size and porosity has been developed. The entire process requires neither organic solvents nor addition of any complexing agent. The thin films were deposited using the spin coating technique from an aqueous solution prepared by dissolving tin(II) oxalate in hydrogen peroxide. X-ray diffraction analysis showed that the deposited films are single-phase and their crystallite size increases as the annealing temperature is increased from 300 to 800 °C. It was also found that the films exhibit a preferred (110) orientation of the crystallites. Scanning electron microscopy and atomic force microscopy were employed for the estimation of thickness and surface morphological features of the films. Thickness of the films after 10 deposition cycles was about 160 nm. Roughness of the films increased with the annealing temperature increasing. It has been found from the UV–Vis spectrometry measurements that the films are highly transparent in visible spectral range. The optical band gap was determined to be in the range from 3.86 to 4.00 eV depending on the annealing temperature.publishe

Chemical solution deposition of la-substituted BiFe0.5Sc0.5O3 perovskite thin films on different substrates

In the present work, polycrystalline Bi0.67La0.33Fe0.5Sc0.5O3 thin films were synthesized using a simple and cost‐effective chemical solution deposition process employing the spin coating tech‐ nique. In order to check the feasibility of the fabrication of thin films on various types of substrates, the films were deposited on Pt‐coated silicon, silicon, sapphire, corundum, fused silica and glass. Based on the results of thermogravimetric analysis of precursor and thermal stability study, it was determined that the optimal annealing temperature for the formation of perovskite structure is 600 °C. It was observed that the relative intensity of the pseudocubic peaks (001)p and (011)p in the XRD patterns is influenced by the nature of substrates, suggesting that the formed crystallites have some preferred orientation. Roughness of the films was determined to be dependent on the nature of the substrate.publishe

Sol-Gel Synthesis and Characterization of Novel Y3−xMxAl5−yVyO12 (M—Na, K) Garnet-Type Compounds

In this study, for the first time to the best of our knowledge, the new garnets Y3−xNaxAl5O12, Y3−xKxAl5O12, Y3Al5−yVyO12, and Y3−xNaxAl5−yVyO12 with various stoichiometric compositions were successfully synthesized by the aqueous sol-gel method. All obtained samples were characterized by X-ray diffraction (XRD) analysis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). It was determined from the XRD results that the formation of monophasic Y3−xNaxAl5O12, Y3−xKxAl5O12, Y3Al5−yVyO12, and Y3−xNaxAl5−yVyO12 garnets is possible only at limited doping levels. The highest substitutional level of doped metal was observed for the YAG doped with sodium (x = 1), and the lowest substitutional level was observed for the YAG doped with vanadium (y = 0.05). Furthermore, the obtained FTIR spectroscopy results were in good agreement with the XRD analysis data, i.e., they confirmed that the YAG is the main crystalline phase in the end products. The SEM was used to study the morphology of the garnets, and the results obtained showed that all synthesized samples were composed of nano-sized agglomerated crystallites

Investigation of lanthanum substitution effects in yttrium aluminium garnet: importance of solid state NMR and EPR methods

Copyright © 2020, Springer Science Business Media, LLC, part of Springer NatureIn this study, yttrium aluminium garnet (YAG) specimens in which yttrium was partially substituted by lanthanum Y3-xLaxAl5O12 (YLaAG) were prepared by an aqueous sol-gel method. YLaAG samples were analyzed by X-ray diffraction (XRD), solid state nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) methods. The presence of Ce3+ ions as an impurity originating from starting material was determined, therefore, luminescence measurements of YLaAG samples were also recorded. It was demonstrated that luminescent properties are strongly dependent on the phase composition of synthesized species. The XRD analysis results showed that only low substitution of yttrium by lanthanum is possible in Y3-xLaxAl5O12 without destroying garnet crystal structure. It was also demonstrated, that solid state NMR and EPR methods are indispensable tools for the explanation of processes and properties observed in the newly synthesized Y3-xLaxAl5O12 compounds. ---- / / / ---- This is the preprint version of the following article: Laurikenas, A., Sakalauskas, D., Marsalka, A. et al. Investigation of lanthanum substitution effects in yttrium aluminium garnet: importance of solid state NMR and EPR methods. J Sol-Gel Sci Technol (2020). https://doi.org/10.1007/s10971-020-05445-2, which has been published in final form at https://link.springer.com/article/10.1007/s10971-020-05445-2. This article may be used for non-commercial purposes in accordance with Springer Terms and Conditions for Sharing and Self-Archiving.This work was supported by a Research grant NEGEMAT (No. S-MIP-19-59) from the Research Council of Lithuania. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²

A novel sol-gel Bi2-xHfxO3+x/2 radiopacifier for mineral trioxide aggregates (MTA) as dental filling materials

Funding Information: The authors would like to thank Taipei Medical University Hospital for financially sup-porting this work under grant no. 110TMU-TMUH-16 and partially supported by MOST 109-2221-E-038-014. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Mineral trioxide aggregate (MTA) is well known as an effective root canal filling material for endodontics therapy. Within MTA, bismuth oxide (Bi2O3) serving as the radiopacifier still has biocompatibility concerns due to its mild cytotoxicity. In the present study, we tried to modify the Bi2O3 radiopacifier by doping hafnium ions via the sol-gel process and investigated the effects of different doping ratios (Bi2-xHfxO3+x/2, x = 0–0.3) and calcination temperatures (400–800 °C). We mixed various precursor mixtures of bismuth nitrate (Bi(NO3)3·5H2O) and hafnium sulfate (Hf(SO4)2) and controlled the calcination temperatures. The as-prepared Hf-doped Bi2O3 radiopaci-fier powders were investigated by thermogravimetric analysis (TGA), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). Portland cement/radiopacifier/calcium sulfate (75/20/5) were mixed and set by deionized water (powder to water ratio = 3:1). Changes in radiopacity, diametral tensile strength (DTS), and in vitro cell viability of the hydrated MTA-like cement were carried out. The experimental results showed that the group containing radiopacifier from sol-gelled Bi/Hf (90/10) exhibited significantly higher radiopacity (6.36 ± 0.34 mmAl), DTS (2.54 ± 0.29 MPa), and cell viability (84.0±8.1%) (p < 0.05) when compared to that of Bi/Hf (100/0) powders. It is suggested that the formation of β-Bi7.78Hf0.22O12.11 phase with hafnium addition and calcining at 700 °C can prepare novel bismuth/haf-nium composite powder that can be used as an alternative radiopacifier for root canal filling mate-rials.publishersversionPeer reviewe

The Processing and Electrical Properties of Isotactic Polypropylene/Copper Nanowire Composites

Funding Information: The authors would like to thank MOST for financially supporting this work under grant No. MOST 110-2224-E-038-001. Publisher Copyright: © 2022 by the authors.Polypropylene (PP), a promising engineering thermoplastic, possesses the advantages of light weight, chemical resistance, and flexible processability, yet preserving insulative properties. For the rising demand for cost-effective electronic devices and system hardware protections, these applications require the proper conductive properties of PP, which can be easily modified. This study investigates the thermal and electrical properties of isotactic polypropylene/copper nanowires (i-PP/CuNWs). The CuNWs were harvested by chemical reduction of CuCl 2 using a reducing agent of glucose, capping agent of hexadecylamine (HDA), and surfactant of PEG-7 glyceryl cocoate. Their morphology, light absorbance, and solution homogeneity were investigated by SEM, UV-visible spectrophotometry, and optical microscopy. The averaged diameters and the length of the CuNWs were 66.4 ± 16.1 nm and 32.4 ± 11.8 µm, respectively. The estimated aspect ratio (L/D, length-to-diameter) was 488 ± 215 which can be recognized as 1-D nanomaterials. Conductive i-PP/CuNWs composites were prepared by solution blending using p-xylene, then melt blending. The thermal analysis and morphology of CuNWs were characterized by DSC, polarized optical microscopy (POM), and SEM, respectively. The melting temperature decreased, but the crystallization temperature increasing of i-PP/CuNWs composites were observed when increasing the content of CuNWs by the melt blending process. The WAXD data reveal the coexistence of Cu 2O and Cu in melt-blended i-PP/CuNWs composites. The fit of the electrical volume resistivity (ρ) with the modified power law equation: ρ = ρ o (V - Vc) -t based on the percolation theory was used to find the percolation concentration. A low percolation threshold value of 0.237 vol% and high critical exponent t of 2.96 for i-PP/CuNWs composites were obtained. The volume resistivity for i-PP/CuNWs composite was 1.57 × 10 7 Ω-cm at 1 vol% of CuNWs as a potential candidate for future conductive materials.publishersversionPeer reviewe

Sonication accelerated formation of Mg-Al-phosphate layered double hydroxide via sol-gel prepared mixed metal oxides

Single-phase magnesium-aluminium layered double hydroxide (LDH) intercalated with dihydrogen phosphate was successfully produced by hydration of nanopowder of the respective mixed metal oxide (MMO) obtained using sol-gel based method followed by a two-step anion exchange hydroxide-to-chloride and chloride-to-phosphate. The MMO with the metal cation ratio of Mg/Al = 2:1 was prepared using the aqueous sol-gel method. Processes of the parent Mg2Al-OH LDH formation and the successive anion-exchanges, ОН- → Cl- and Cl- → H2PO4-, were considerably accelerated via the application of high-power (1.5 kW) ultrasound. The crystalline phases formed at all stages of the Mg2Al-H2PO4 LDH production were characterized using X-ray diffraction, scanning electron microscopy, scanning transmission electron microscopy, inductive coupled plasma optical emission spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Based on the data of chemical analysis and the XRD data, the type of the intercalated phosphate anion was determined and the arrangement of this anion in the interlayer was modelled.publishe

Advances in Functional Inorganic Materials Prepared by Wet Chemical Methods

Functional inorganic materials are an indispensable part of innovative technologies, which are essential to the development of many fields of industry [...

Advances in Functional Inorganic Materials Prepared by Wet Chemical Methods (Volume II)

Functional inorganic materials are an indispensable part of innovative technologies, which are essential for development in many fields of industry [...

Hydrothermal Synthesis of Well-Defined Red-Emitting Eu-Doped GdPO4 Nanophosphors and Investigation of Their Morphology and Optical Properties

Rare-earth-doped GdPO4 nanoparticles have recently attracted much scientific interest due to the simultaneous optical and magnetic properties of these materials and their possible application in bio-imaging. Herein, we report the hydrothermal synthesis of GdPO4:Eu3+ nanoparticles by varying different synthesis parameters: pH, &lt;Gd&gt;:&lt;P&gt; molar ratio, and Eu3+ concentration. It turned out that the Eu3+ content in the synthesized nanoparticles had little effect on particle shape and morphology. The synthesis media pH, however, has showed a pronounced impact on particle size and distribution, i.e., the nanoparticle length can be adjusted from hundreds to tens of nanometers by changing the pH from 2 to 11, respectively. Increasing the &lt;Gd&gt;:&lt;P&gt; molar ratio resulted in a decrease in nanoparticle length and an increase in its width. The temperature-dependent measurements in the 77&ndash;500 K range revealed that the GdPO4:50%Eu3+ sample maintains half of its emission intensity, even at room temperature (TQ1/2 = 291 &plusmn; 19 K)