Antimony Pentoxide Research Articles

Integration of Hydrated Antimony Pentoxide in Poly(vinylidene fluoride) Films for Enhanced Energy Storage and Harvesting

Integration of Hydrated Antimony Pentoxide in Poly(vinylidene fluoride) Films for Enhanced Energy Storage and Harvesting

Composite Flame Retardants Based on Conjugated Microporous Polymer Hollow Nanospheres with Excellent Flame Retardancy.

The development of polymer materials with excellent flame retardancy has been paid increasing attention for their valuable applications in saving energy in modern architecture. Herein, conjugated microporous polymers hollow nanospheres (CMPs-HNS) were prepared by Sonogashira-Hagihara cross-coupling reaction with 1,3,5-triacetylenebenzene, 3-amino-2,6-dibromopyridine, and 2,4,6-tribromoaniline as building blocks using SiO2 nanoparticles as hard templates. To enhance the flame-retardant performance of the CMPs-HNS, antimony pentoxide solution (Sb2O5) and bisphenol A-bis (diphenyl phosphate) (BDP) were coated onto the as-prepared CMP-HNS (CMPs-HNS-BSb) by a simple immersion method. The peak heat release (pHRR) from microscale combustion colorimeter (MCC) of CMPs-HNS-BSb was 76.5 and 73.05 W g-1, respectively. By introducing CMPs-HNS-BSb into the epoxy resin (EP) matrix, the CMP2-HNS-BSb/EP (0.5) composites show that the pHRR values were 809.3 and 645.2 kW m-2, reduced by 21% as measured by conical calorimetry (CC), and total heat release (THR) reduced by 29.7%, going from 101 to 70.8 MJ/m2 when compared to the pure sample. Besides, total smoke production (TSP) reduced about 23.7%. The hollow structure can enhance the thermal insulation performance. As measured, the thermal conductivity of CMP1-HNS-BSb and CMP2-HNS-BSb is 0.044 and 0.048 W m-1 K-1. Based on the advantages of simple manufacture, superior thermal insulation, and flame retardancy, our CMPs-HNS-BSb/EP composites may find useful applications in various aspects such as building energy saving in future development.

Effects of Sb doping on the electrical characteristics of Ta-doped SnO2 varistors

This article describes the combined mixture of antimony and tantalum in SnO2 varistors. The results show that a moderate level of antimony can reduce the grain resistivity and maintain a high voltage gradient while providing good nonlinearity. The best electrical properties were obtained by doping 0.5 mol% antimony pentoxide and 0.003 mol% tantalum pentoxide. The nonlinear coefficient of 51, the leakage current of 5.7 μA/cm2, the voltage gradient of 480 V/mm and the grain resistance of 5.0 Ω.

Equilibrium mass-dependent isotope fractionation of antimony between stibnite and Sb secondary minerals: A first-principles study

Antimony (Sb) isotopes are gaining increasing interest for their potential as geochemical tracers in geological, environmental and archaeological studies. However, little is known about the parameters controlling Sb isotope fractionation, which is essential to interpret variations of isotopic signature in natural systems. In this study, equilibrium mass-dependent isotope fractionation factors (β-factor) were calculated between different Sb-bearing minerals commonly found in mining environments including primary Sb sulphide (stibnite Sb2S3) and its oxidation products (valentinite Sb2O3, senarmontite Sb2O3, cervantite Sb2O4) and synthetic antimony pentoxide Sb2O5. First-principles calculations within the Density Functional Theory (DFT) were performed with different functionals to test the robustness of the method. Among the studied minerals, stibnite has the lowest β-factor (ln(β) = 0.71 ‰ at 22°C), then β-factors progressively increase from valentinite (ln(β) = 1.64 ‰ at 22°C), to senarmontite (ln(β) = 1.80 ‰ at 22°C), cervantite (ln(β) = 2.20 ‰ at 22°C) and antimony pentoxide (ln(β) = 3.03 ‰ at 22°C). The factors that most fractionate Sb isotopes are found to be i) the change of Sb oxidation state (Sb isotope ratio in Sb(V)-bearing minerals is higher than in Sb(III)-bearing minerals), ii) the change of first neighbour of Sb (Sb isotope ratio in SbO bonds is higher than in SbS bonds) and iii) distortion of the atomic SbO polyhedrons. The negligible differences in the β-factors obtained with different functionals showed the robustness of the approach for the calculation of β-factors, despite differences in the calculated mineral lattice and Raman frequencies. The results of this study provide a theoretical basis to interpret natural Sb isotope variations. The results suggest that a significant enrichment in the heavy isotope could occur during oxidative dissolution of stibnite and subsequent precipitation of Sb(III) and Sb(V) oxides in sulphide environments. More generally, this work strongly supports that Sb isotopes may be a useful tracer of Sb transformation processes in nature.

Study on the Flame Retardancy and Hazard Evaluation of Poly(acrylonitrile-co-vinylidene chloride) Fibers by the Addition of Antimony-Based Flame Retardants.

Antimony oxide (ATO) is used mainly as a flame retardant, but it is classified as a hazardous substance. Therefore, regulations on the use of antimony trioxide (ATO(3)) and antimony pentoxide (ATO(5)) in textile products are being developed. Accordingly, there is a need for alternative flame retardants. In this study, antimony tetroxide (ATO(4)), which has higher thermal stability and resistance to acids and alkalis than ATO(3) or ATO(5), was selected to assess its use as an alternative flame retardant. First, ATO(3) or ATO(4) were added to poly(acrylonitrile-co-vinylidene chloride) (PANVDC), and the film and wet-spun fiber were prepared. The PANVDC film with flame retardants was prepared to evaluate the flame retardancy and the mechanism of action of the flame retardants. Flame retardancy analysis showed that a limiting oxygen index of 31.2% was obtained when ATO(4) was added, which was higher than when ATO(3) was used. Subsequently, PANVDC fibers with antimony oxide were manufactured and showed improved mechanical and thermal properties when ATO(4) was used, compared to when ATO(3) was tested. In addition, migration analysis due to antimony in the fiber confirmed that the elution amount was below the acceptable standard when PANVDC fibers with ATO(4) were added. Therefore, based on these results, the flame-retardant and thermal properties of antimony tetroxide were superior to antimony trioxide, and it was confirmed that ATO(4) could be used as an alternative flame retardant to ATO(3).

Thermolysis of Hydrated Antimony Pentoxide

The thermolysis of hydrated antimony pentoxide (HAP) has been studied in the temperature range from 25 to 1000°C using a variety of experimental techniques: thermogravimetry, X-ray diffraction, pycnometry, elemental microanalysis, and mass spectrometry. The composition and structure of the forming phases have been determined. It has been shown that the initial stages of HAP thermolysis, in the temperature range 24–500°C, include dehydration processes and the formation of anhydrous antimony pentoxide, Sb2O5. At temperatures above 500°C, the process includes oxygen removal, the reduction of Sb(V) to Sb(III), and the formation of Sb6O13 and Sb2O4. The pyrochlore structure of HAP (sp. gr. Fd3m) has been shown to persist in the course of the phase transformations at temperatures below 700°C. Analysis of our experimental data has allowed us to propose a model for crystallographic site occupancies in the pyrochlore-type structure of the phases obtained and determine their temperature stability ranges.

Superhydrophobicity, Self-cleaning and Flame Retardancy Properties of Cotton Fabric

A simple and facile method for fabricating the cotton fabric with superhydrophobicity, self-cleaning and flame retardancy was described in the present work. Three types of antimony pentoxide sol (Sb2O5), aluminum hydroxide sol (Al(OH)3) and 1H,1H,2H,2H-perfluorodecyltriethoxysilane (fluoroalkyl silanes) were used as coating for the cotton fabric. It was found that Sb2O5 and Al(OH)3 exhibited significant synergistic effects on the flame retardancy. When the weight ratio of Sb2O5/Al(OH)3(content 30 wt%) was 1:3, the results showed that the limiting oxygen index (LOI) value was 45.1 %, smoke density (SDR) value was 35 %, and it still passed UL94 V-0 rating. The cotton fabrics coated with fluoroalkyl silanes/Sb2O5/ Al(OH)3 showed a superhydrophobicity, anti-contamination and self-cleaning properties. In addition, the results exhibited the outstanding superhydrophobicity, oil/water separation, excellent waterproofing durability and flame retardancy of cotton fabric after 1000 cycles of washing by water, the LOI value was 40.1 %, SDR value was 39 % and WCA was 152° after 1000 cycles of washing. We believe that this simple, environmentally friendly and versatile fabrication of the cotton fabric had excellent real-life applications.

In English

In this study cellulose-inorganic sorbents based on bleached cotton fibres and hydrated antimony pentoxide were prepared and used for strontium ions sorption from model aqueous solutions. The adsorption of strontium ions was determined by the radiotracer method using radioisotopes. A comparative analysis was made of sorption properties of the obtained sorption materials with different contents of hydrated antimony pentoxide towards strontium ions. The efficiency of strontium sorption increases with the increase in the modifier content in the composite cellulose-inorganic sorbents. The maximum efficiency of strontium sorption from solution (99 %) and the maximum distribution coefficient (1400 ml/g) correspond to the sorbents with the hydrated antimony pentoxide content 2.9 %. The effect of pH on the density of ions sorption on the cellulose-inorganic sorbent and the distribution coefficient was investigated. The experimentally determined density of ions sorption and distribution coefficient for strontium varied between 0.045 and 0.076 µmol/m 2 and between 100 and 1400 ml/g respectively depending on pH of model aqueous solutions. Chemical and structural properties were investigated by the low temperature nitrogen adsorption–desorption method, X-ray diffraction, infrared spectroscopy, differential thermal analysis. Surface area of the sorbents was determined by Brunauer, Emmett and Teller method. All composite cellulose-inorganic sorbents were characterized by a low specific surface area (1 m 2 /g). Hydrated antimony pentoxide characterized by amorphous structure and modification process does not affect cellulose crystallinity.

New Composite Sorbents for Caesium and Strontium Ions Sorption

(PDF) Graphical Abstract: Composite lignocellulose-inorganic sorbents derived from plant residues of agriculture and food industry, modified with ferrocyanides of d-metals and hydrated antimony pentoxide were prepared. Caesium and strontium ions removal from water was tested by radiotracer method. Sorption of heavy metal ions, methylene blue, gelatin, vitamin B12 was also studied.

Removal of antimony from concentrated solutions with focus on tripuhyite (FeSbO4) synthesis, characterization and stability

The precipitation of antimony (Sb) from acidic aqueous solutions (6g·L−1 Sb) as ferric antimonate, FeSbO4 (tripuhyite), its further crystallization by hydrothermal or calcination treatment and the determination of its degree of stability were investigated. The precipitation was studied over the pH range 1.5–5.3 at 95°C via the oxidation of Sb(III) and Fe(II) by drop-wise H2O2 addition. Among all tests, oxidation at pH5.3 over ≈3.5h with 10wt% H2O2 was retained as best precipitation protocol. The precipitate was characterized as poorly crystalline tripuhyite (possessing high specific surface area in the order of 160–200m2·g−1). Hydrothermal treatment in pH1 water was done at 200°C for 12h, while calcination at 950°C for 12h to increase crystallinity, the latter being more effective. A separate highly crystalline tripuhyite product was synthesized at high temperature (950°C) by solid–state reaction of goethite and antimony pentoxide in order to serve as reference. The stability/leachability tests indicated that pseudo–equilibrium was attained by all synthesized materials in ≈15days. Between pH6 and 8, the untreated precipitate released 100–170mg·L−1 Sb, hydrothermally treated precipitate released ≈0.5mg·L−1 Sb, calcined precipitate released 10–35mg·L−1 Sb, and the reference tripuhyite released ≈0.5mg·L−1 Sb. The results suggested that stability was mainly a function of tripuhyite crystallinity rather than pH (over the 6–8 range tested). The hydrothermally treated precipitate demonstrated the highest stability (aside from the synthetic reference material). The relatively higher Sb release recorded by the calcined precipitate was traced to its contamination with NaSbO3, a secondary high temperature phase. Lastly, tripuhyite produced via aqueous precipitation and hydrothermal treatment appears to offer a viable option in fixing antimony from metallurgical waste streams.

Selective esterification of glycerol with acetic acid to diacetin using antimony pentoxide as reusable catalyst

Glycerol can be obtained as a by-product during biodiesel manufacture. It is important to convert glycerol to value-added products. Glycerol esterification with acetic acid is one of the most promising approaches for glycerol utilization. It is usually difficult to obtain diacetin with good activity and selectivity. In this work, glycerol esterification with acetic acid over different metal oxides, such as Bi2O3, Sb2O3, SnO2, TiO2, Nb2O5 and Sb2O5, was investigated. It was found that in the six investigated metal oxides, only Sb2O5 resulted in good activity and selectivity to diacetin. Under the optimized conditions, the glycerol conversion reached 96.8%, and the selectivity to diacetin reached 54.2%, while the selectivity to monoacetin and triacetin was 33.2% and 12.6%, respectively. The catalysts were characterized with FT-IR spectra of adsorbed pyridine, which indicated that in the six investigated metal oxides, only Sb2O5 possessed Brønsted acid sites strong enough to protonate adsorbed pyridine. The good catalytic activity and selectivity to diacetin might be mainly attributable to the Brønsted acid sites of Sb2O5. Reusability tests showed that with Sb2O5 as catalyst, after six reaction cycles, no significant change in the glycerol conversion and the selectivity to diacetin was observed.

Antimony recovery from SbCl5 acid solution by hydrolysis and aging

This study aimed to find an efficient way to recover Sb from the SbCl5 acid solution obtained by the chloride leaching process of the tin-depleted residue. Sb was recovered in the form of hydrated antimony pentoxide through the hydrolysis process. The effects of hydrolysis ratio and aging time on the Sb recovery process were studied, and the corresponding trends were established. The experimental results show that the amount of the antimony free ions increases with the hydrolysis ratio and aging time. This decreases the concentration quotient of the hydrolysis reaction and thus facilitates the reaction. Product crystallinity is affected by the solution supersaturation, which varies at different stages with aging time. As a result, the optimal conditions of recovering Sb correspond to the hydrolysis ratio of 1.5 and aging time of 7 days with the recovery rate of 97 %.

Preparation of Colloidal Antimony Pentoxide and Synergist Effect on Brominated Flame Retardant

Colloidal Antimony Pentoxide was prepared through a simple method based on reflux oxidization system. Detailed investigations about the effects of experimental parameters on the colloid stability and size distribution of the final products were carried out. The use of the combination of a brominated flame retardant 2,3-dibromo-succinic anhydride (DBrFR) as the flame-retarding agent and colloidal antimony pentoxide (APO) as the synergist to reduce the flammability of PET/cotton blend fabric was also studied. The BFR was effective in reducing the flammability of the blended fabric whereas APO enhances the effectiveness of DBrFR due to bromine–antimony synergism. The limiting oxygen index (LOI) value and the breaking strength retention of PET/ cotton fabric treated with DBrFR and APO were studied and the thermal behaviors of different treated fabrics were investigated via thermo gravimetric analysis (TGA).

Strontium(II) adsorption on Sb(III)/Sb2O5

The rapid development of the nuclear power plants (NPPs) in China leads to an increasing attention to the treatment of low-level radioactive wastewater (LLRW). One of the possibilities is the application of antimony pentoxide based ion exchange materials, which can exhibit effective adsorption of 90Sr. In this paper, a novel sorbent Sb(III)/Sb2O5 is prepared by sol–gel method and its structure and surface properties are determined by X-ray photoelectron spectra (XPS), X-ray diffraction (XRD), zeta potential, surface area and porosity analysis. The batch experiments demonstrate a very efficient and selective Sr(II) elimination over a wide pH range from 2.0 to 12.0. At Sb(III)/Sb (total) ratio of 0.41, the optimum adsorption can be achieved with Kd value of 8.8×108mL/g. The co-existing calcium ions can affect the adsorption of strontium, since the Kd value drops to 103–102mL/g with calcium concentration increases to 0.1mol/L. Compared with divalent cations, the monovalent cations like Na+ and K+ have only minor influence. The strontium adsorption isotherm coincides very well with Freundlich model. The KF values are 10.7mg/g at 283K, 23.2mg/g at 303K, and 40.6mg/g at 323K. The thermodynamic studies reveal an endothermic and spontaneous process. The kinetic performance follows the pseudo-second-order adsorption model, with intra particle diffusion as the rate controlling step.

K 0-RNAA used in determination of 129I in a mixed resin sample

A k 0-RNAA procedure was developed to determine 129I in a mixed resin sample. CH4 extraction and (NH4)2SO3 back-extraction were used to separate 129I in ashed samples. The 129I target sample for irradiation in the reactor was prepared by heating the (NH4)2SO3 back-extraction solution to reduce its volume and then to dry it in a quartz ampoule. No MgO and LiOH were needed during the target sample preparation. After irradiation, the nuclide 130I was purified by combining hydrated antimony pentoxide column and CH4 extraction separations. A k-factor was determined for the reaction of 127I (n, 2n) 126I and used for iodine chemical yield determination. The apparent 129I concentrations of five nuclear reaction interferences were calculated. The relative standard deviation of three 129I determinations was found to be 3.5 %. The 129I content in the analyzed resin was found to be 1.36 × 10−9 g/g (8.63 × 10−3 Bq/g) with a relative uncertainty of 9.1 %. The detection limit of 129I was calculated to be 7.4 × 10−13 g (4.7 × 10−6 Bq) in a k 0-RNAA of a blank sample.

Nanocrystalline Antimony Oxide Films for Dye-Sensitized Solar Cell Applications

A new photoelectrode composed of nanoparticles with the size of 20-30 nm has been prepared via thermolysis of a colloidal antimony pentoxide tetrahydrate () suspension. The electrode showed good semiconducting properties applicable to dye-sensitized solar cells (DSSCs); the energy band gap was estimated to be eV and the position of conduction band edge was close to those of and ZnO. The DSSC assembled with the photoelectrode and a conventional ruthenium-dye (N719) exhibited the overall photo-current conversion efficiency of 0.74% ( = 0.76 V, , fill factor = 0.49) under AM 1.5, illumination.

Assessment of the effect of nanomaterials on sediment-dwelling invertebrate Chironomus tentans larvae

Studies were conducted to determine the effects of a panel of seven nanomaterials (NMs), namely: α-alumina, γ-alumina, precipitated silica; silica fume, calcined silica fume, colloidal antimony pentoxide (Sb2O5), and superfine amorphous ferric oxide (Fe2O3), on sediment dwelling invertebrates Chironomus tentans under controlled laboratory conditions. Percentage survival, enzyme activities, growth development, and DNA fragmentation parameters were studied as acute, biochemical, and physiological toxicities of NMs, respectively. Quantitation of catalase and peroxidase enzyme activity demonstrated that toxicant stress of the NMs increased enzyme activity in a concentration dependent fashion across all treatments. The percentage growth length of the test specimens exposed to different NMs was significantly reduced compared to the negative control while only five concentrations were not in the toxic range, namely; Fe2O3 (5μg/kg); silica fume (5μg/kg, 50μg/kg); Sb2O5 (5μg/kg) and calcined silica fume (5μg/kg). Genotoxic stress assessed by use of DNA laddering showed complementary findings to the other ecotoxicological endpoints tested in this study—the percentage survival and growth length inhibition.

Review on oxides of antimony nanoparticles: synthesis, properties, and applications

In this article, synthesis methods, properties, and applications of antimony oxide nanoparticles are reviewed. Oxides of antimony exist in three phases, namely antimony trioxide, antimony tetroxide, and antimony pentoxide. Physical and optical properties of these nanoparticles are reviewed and compared with their bulk forms. According to literature works, a total of eight synthesis methods have been used to produce these nanoparticles. The size, distribution, shape, and structure of the nanoparticles which are synthesized by different methods are compiled and compared. It is reported that the properties are strongly dependent on the synthesis methods. Advantages and disadvantages of each synthesis method are discussed and compared. Most literatures report on the optical and physical properties of the nanoparticles. Reports on the electrical properties are scarce. As the applications of these nanoparticles cover a wide range, several challenges must be overcome to use them well. These challenges are also being presented and explained in this article.

Synthesis of nearly monodisperse ultrafine antimony pentoxide

Nearly monodisperse antimony pentoxide with a mean diameter of 2 nm and polydispersity of 0.047 was prepared through a simple method based on reflux oxidization system. By adjusting the synthetic parameters (kinds of stabilizing agents, size and purity of original Sb 2O 3 etc.), the controllable synthesis of ultrafine Sb 2O 5 can be easily achieved. Detailed investigations about the effects of experimental parameters on the colloid stability and size distribution of the final products were carried out. The particles were characterized using various experimental techniques such as transmission electron microscopy (TEM), X-ray diffraction (XRD) and particle size distributions.

Mechanochemical synthesis of FeSbO 4-based materials from FeOOH and Sb 2O 5 powders

Iron antimony oxide (FeSbO 4) with specific surface area (SSA) over 50 m 2/g was synthesized mechanochemically by milling a mixture of iron oxy-hydroxide (FeOOH) and antimony pentoxide (Sb 2O 5) using a planetary ball mill at room temperature. The mechanochemical reaction proceeds with an increase in milling time and has been completed by 120 min. The prepared product powders are in the state of agglomerates consisted of fine particles of several dozen nanometers. This method has been extended to synthesis of FeSbO 4-based materials with different Fe/Sb atomic ratios (1 ≤ Fe/Sb ≤ 4). The SSA value of these prepared samples is in the range of 50 to 65 m 2/g.