scholarly journals Probing the Effect of Titanium Substitution on the Sodium Storage in Na3Ni2BiO6 Honeycomb-Type Structure

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6498
Author(s):  
Eugen Zemlyanushin ◽  
Kristina Pfeifer ◽  
Angelina Sarapulova ◽  
Martin Etter ◽  
Helmut Ehrenberg ◽  
...  
Keyword(s):  
Critical Concentration ◽  
Sol Gel ◽  
Honeycomb Structure ◽  
Electrochemical Process ◽  
Electrochemical Kinetics ◽  
Fast Diffusion ◽  
Reversible Phase Transition ◽  
Synchrotron Radiation Diffraction ◽  
Na Ions ◽  
The Stability

Na3Ni2BiO6 with Honeycomb structure suffers from poor cycle stability when applied as cathode material for sodium-ion batteries. Herein, the strategy to improve the stability is to substitute Ni and Bi with inactive Ti. Monoclinic Na3Ni2-xBi1-yTix+yO6 powders with different Ti content were successfully synthesized via sol gel method, and 0.3 mol of Ti was determined as a maximum concentration to obtain a phase-pure compound. A solid-solution in the system of O3-NaNi0.5Ti0.5O2 and O3-Na3Ni2BiO6 is obtained when this critical concentration is not exceeded. The capacity of the first desodiation process at 0.1 C of Na3Ni2BiO6 (~93 mAh g−1) decreases with the increasing Ti concentration to ~77 mAh g−1 for Na3Ni2Bi0.9Ti0.1O6 and to ~82 mAh g−1 for Na3Ni0.9Bi0.8Ti0.3O6, respectively. After 100 cycles at 1 C, a better electrochemical kinetics is obtained for the Ti-containing structures, where a fast diffusion effect of Na+-ions is more pronounced. As a result of in operando synchrotron radiation diffraction, during the first sodiation (O1-P3-O’3-O3) the O’3 phase, which is formed in the Na3Ni2BiO6 is fully or partly replaced by P’3 phase in the Ti substituted compounds. This leads to an improvement in the kinetics of the electrochemical process. The pathway through prismatic sites of Na+-ions in the P’3 phase seems to be more favourable than through octahedral sites of O’3 phase. Additionally, at high potential, a partial suppression of the reversible phase transition P3-O1-P3 is revealed.

UV Curable Organic-Inorganic Hybrid Materials

2000 ◽  
Vol 628 ◽  
Author(s):  
Guang-Way Jang ◽  
Ren-Jye Wu ◽  
Yuung-Ching Sheen ◽  
Ya-Hui Lin ◽  
Chi-Jung Chang
Keyword(s):  
Hybrid Materials ◽  
Colloidal Silica ◽  
Sol Gel ◽  
Solution Ph ◽  
Uv Curable ◽  
Inorganic Hybrid ◽  
Degradation Temperature ◽  
Sol Gel Process ◽  
The Stability ◽  
Thermal Degradation Temperature

This work successfully prepared an UV curable organic-inorganic hybrid material consisting of organic modified colloidal silica. Applications of UV curable organic-inorganic hybrid materials include abrasion resistant coatings, photo-patternable thin films and waveguides. Colloidal silica containing reactive functional groups were also prepared by reacting organic silane and tetraethyl orthosilicate (TEOS) using sol-gel process. In addition, the efficiency of grafting organic moiety onto silica nanoparticles was investigated by applying TGA and FTIR techniques. Experimental results indicated a strong interdependence between surface modification efficiency and solution pH. Acrylate-SiO2 hybrid formation could result in a shifting of thermal degradation temperature of organic component from about 200°C to near 400°C. In addition, the stability of organic modified colloidal silica in UV curable formula and the physical properties of resulting coatings were discussed. Furthermore, the morphology of organic modified colloidal silica was investigated by performing TEM and SEM studies‥

scholarly journals Kinetics and mechanism of sol-gel transformation between some trivalent- and tetravalent-metal ions and Sodium alginate Anionic polyelectrolyte with formation of coordination Biopolymeric structure polymembranes Hydrogels of Capillary Structures Ex

2007 ◽  
Vol 3 (1) ◽  
pp. 133-142 ◽  
Author(s):  
Ishaq Abdullah Zaafarany
Keyword(s):  
Sodium Alginate ◽  
Metal Ion ◽  
Sol Gel ◽  
Coordination Geometry ◽  
Large Excess ◽  
First Order ◽  
Pseudo First Order ◽  
The Stability ◽  
Kinetics Of ◽  
Overall Kinetics

Abstract          The kinetics of sol-gel transformation between A13+, La 3+ and Th4+ metal ion electrolytes and sodium alginate sol have been studied complexometrically at various  temperatures. In the presence of a large excess of sodium alginate sol concentration over that of metal ion electrolyte, the pseudo first–order plots of exchange showed sigmoidal curves with two distinct stages. The initial part was relatively fast and curved significantly at early times, followed by a slow decrease in the rates of exchange over longer time periods. The rate constants of gelation showed second-order overall kinetics which was first order in the concentration of both reactants. The thermodynamic parameters have been evaluated and tentative gelation mechanisms consistent with the kinetic results of gelation are suggested. The stability of these ionotropic metal-alginate complexes has been discussed in terms of the coordination geometry and strength of chelated bonds.

scholarly journals Critical Concentration of Lecithin Enhances the Antimicrobial Activity of Eugenol against Escherichia coli

2017 ◽  
Vol 83 (8) ◽  
Author(s):  
Haoshu Zhang ◽  
Edward G. Dudley ◽  
P. Michael Davidson ◽  
Federico Harte
Keyword(s):  
Escherichia Coli ◽  
Essential Oils ◽  
Food Systems ◽  
Critical Concentration ◽  
Physical Stability ◽  
Antimicrobial Properties ◽  
Content Type ◽  
Antimicrobial Effects ◽  
Wide Range ◽  
The Stability

ABSTRACT Lecithin is a natural emulsifier used in a wide range of food and nonfood applications to improve physical stability, with no known bioactive effects. In this study, the effect of lecithin on the antimicrobial performance of a constant eugenol concentration was tested against three Escherichia coli strains (C600, 0.1229, and O157:H7 strain ATCC 700728). This is the first study, to our knowledge, focusing on lecithin at concentrations below those commonly used in foods to improve the stability of oil in water emulsions (≤10 mg/100 ml). For all three cultures, significant synergistic antimicrobial effects were observed when E. coli cultures were exposed to a constant eugenol concentration (ranging from 0.043 to 0.050% [wt/wt]) together with critical lecithin concentrations ranging from 0.5 to 1 mg/100 ml. Increasing the concentration of lecithin above 1 mg/100 ml (up to 10 mg/100 ml lecithin) diminished the antibacterial effect to values similar to those with eugenol-only treatments. The formation of aggregates (<100 nm) at the critical lecithin concentration was observed using cryo-transmission electron microscopy (cryo-TEM), together with a reduction in light absorbance at 284 nm. At critically low concentrations of lecithin, the formation of nanoscale aggregates is responsible for improving eugenol antimicrobial effects. IMPORTANCE Essential oils (EOs) are effective natural antimicrobials. However, their hydrophobicity and strong aromatic character limit the use of essential oils in food systems. Emulsifiers (e.g., lecithin) increase the stability of EOs in water-based systems but fail to consistently improve antimicrobial effects. We demonstrate that lecithin, within a narrow critical concentration window, can enhance the antimicrobial properties of eugenol. This study highlights the potential bioactivity of lecithin when utilized to effectively control foodborne pathogens.

Investigation of vacancy defects and substitutional doping in AlSb monolayer with double layer honeycomb structure: a first-principles calculation

2021 ◽  
Author(s):  
Asadollah Bafekry ◽  
M. Faraji ◽  
Siavash Karbasizadeh ◽  
Hamad R. Jappor ◽  
Abdolhosseini Sarsari ◽  
...  
Keyword(s):  
Formation Energy ◽  
Bulk Material ◽  
Functional Method ◽  
Honeycomb Structure ◽  
First Principles Calculation ◽  
Ferromagnetic Behavior ◽  
Hybrid Functional ◽  
Vacancy Defects ◽  
Substitutional Doping ◽  
The Stability

Abstract The experimental knowledge of the AlSb monolayer is largely based on the recent publication [Le Qin et al., ACS Nano 2021, 15, 8184], where this monolayer was recently synthesized. Therefore, the aim of our research is to consequently explore the effects of substitutional doping and vacancy point defects on the electronic and magnetic properties of the novel hexagonal AlSb monolayer. Besides experimental reports, the phonon band structure and cohesive energy calculations confirm the stability of the AlSb monolayer. Its direct bandgap has been estimated to be 0.9 eV via the hybrid functional method (HSE), which is smaller than the value of 1.6 eV of bulk material. The majority of vacancy defects and substitutional dopants change the electronic properties of the AlSb monolayer from semiconducting to metallic. Moreover, the Mg_Sb impurity has demonstrated the addition of ferromagnetic behavior to the material. It is revealed through the calculation of formation energy that in Al-rich conditions, the vacant site of V_Sb is the most stable, while in Sb-rich circumstances the point defect of V_Al gets the title. The formation energy has also been calculated for the substitutional dopants, showing relative stability of the defected structures. We undertook this theoretical study to inspire many experimentalists to focus their efforts on AlSb monolayer growth incorporating different impurities. It has been shown here that defect engineering is a powerful tool to tune the properties of novel AlSb two-dimensional monolayer for advanced nanoelectronic applications.

scholarly journals Chemical Preparation Routes and Lowering the Sintering Temperature of Ceramics

Ceramics ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 312-339
Author(s):  
Philippe Colomban
Keyword(s):  
Electrode Materials ◽  
Sintering Temperature ◽  
Microwave Sintering ◽  
Sol Gel ◽  
Transient Liquid Phase ◽  
Ceramic Matrix Composites ◽  
Thermomechanical Properties ◽  
Matrix Composites ◽  
Chemical Preparation ◽  
The Stability

Chemically and thermally stable ceramics are required for many applications. Many characteristics (electrochemical stability, high thermomechanical properties, etc.) directly or indirectly imply the use of refractory materials. Many devices require the association of different materials with variable melting/decomposition temperatures, which requires their co-firing at a common temperature, far from being the most efficient for materials prepared by conventional routes (materials having the stability lowest temperature determines the maximal firing temperature). We review here the different strategies that can be implemented to lower the sintering temperature by means of chemical preparation routes of oxides, (oxy)carbides, and (oxy)nitrides: wet chemical and sol–gel process, metal-organic precursors, control of heterogeneity and composition, transient liquid phase at the grain boundaries, microwave sintering, etc. Examples are chosen from fibers and ceramic matrix composites (CMCs), (opto-)ferroelectric, electrolytes and electrode materials for energy storage and production devices (beta alumina, ferrites, zirconia, ceria, zirconates, phosphates, and Na superionic conductor (NASICON)) which have specific requirements due to multivalent composition and non-stoichiometry.

Environmental Effects in Gel Derived Silicates

1984 ◽  
Vol 32 ◽  
Author(s):  
L.L. Hench
Keyword(s):  
Corrosion Resistance ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Thermal Exposure ◽  
Scientific Basis ◽  
Environmental Stability ◽  
Processing Variables ◽  
End Use ◽  
The Stability ◽  
Gel Processing

Various methods have been developed for producing crystals, powders, coatings and monoliths from gels [1]. The scientific basis for understanding compositional effects, gelation, aging, drying and densification is also advancing rapidly [2]. However, there is as yet relatively little information on the durability, weathering, or corrosion resistance of glasses, glass-ceramics, ceramics, or composites made via the gel route. Data is also sparse on the effects of vacuum, thermal exposure, or mechanical stress on the stability of gel-derived solids. Relationships between sol-gel processing variables and environmental stability are especially lacking at the present time. Since many end-use applications of gel derived materials involve exposure to severe environments, it is essential that the durability of these materials be established during their development.

scholarly journals Sol-gel prepared active ternary oxide coating on titanium in cathodic protection

2007 ◽  
Vol 72 (12) ◽  
pp. 1393-1402 ◽  
Author(s):  
Vladimir Panic ◽  
Branislav Nikolic
Keyword(s):  
Cathodic Protection ◽  
Sol Gel ◽  
Oxide Coating ◽  
Molar Ratio ◽  
Ternary Oxide ◽  
Electrochemical Characteristics ◽  
Accelerated Corrosion ◽  
Metal Chlorides ◽  
Corrosion Stability ◽  
The Stability

The characteristics of a ternary oxide coating, on titanium, which consisted of TiO2, RuO2 and IrO2 in the molar ratio 0.6:0.3:0.1, calculated on the metal atom, were investigated for potential application for cathodic protection in a seawater environment. The oxide coatings on titanium were prepared by the sol-gel procedure from a mixture of inorganic oxide sols, which were obtained by forced hydrolysis of metal chlorides. The morphology of the coating was examined by scanning electron microscopy. The electrochemical properties of activated titanium anodes were investigated by cyclic voltammetry and polarization measurements in a H2SO4- and NaCl-containing electrolyte, as well as in seawater sampled on the Adriatic coast in Tivat, Montenegro. The anode stability during operation in seawater was investigated by the galvanostatic accelerated corrosion stability test. The morphology and electrochemical characteristics of the ternary coating are compared to that of a sol-gel-prepared binary Ti0.6Ru0.4O2 coating. The activity of the ternary coating was similar to that of the binary Ti0.6Ru0.4O2 coating in the investigated solutions. However, the stability in seawater is found to be considerably greater for the ternary coating.

TiO2 and ZnO Water Sol Preparation by Sol–Gel Method and Application on Polyester Fabric of Antistatic Finishing

2011 ◽  
Vol 331 ◽  
pp. 270-274 ◽  
Author(s):  
Yan Yan Chu ◽  
Qing Wang ◽  
Shi Zhong Cui
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Sol Gel ◽  
Physical And Mechanical Properties ◽  
Polyester Fabric ◽  
Pure Tio2 ◽  
The Other ◽  
Baking Process ◽  
Result Show ◽  
The Stability

Abstract：Pure TiO2 water sol, pure ZnO water sol and three compound TiO2/ZnO water sols are prepared under low temperature. Then the padding and baking process is used to put the functional sol liquid on the fabric. SEM is use to analyzed the change of surface feature and the result show that all of the water sol except pure ZnO water sol liquid formed a thin film on the fiber The stability of pure ZnO water sol is the best one and the pure TiO2 water sol is the worst one at temperature of 15°C. The compound water sols stabilities are between these two water sols and with the more amount of ZnO, the stability last longer. Both mole of TiO2 and ZnO with the rate of 5 to 5 and 7 to 3 display the best antistatic behavior, but the washing fastnesses are not good. After treatment, the moisture regain displays most dramatically changes; the next one is whiteness of fabric, but the other physical and mechanical properties have a little change.

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