Boric Oxide Research Articles

Synthesis of plate-like cordierite using a small amount of H3BO3 flux

This work aimed to prepare high-purity, plate-like cordierite powder at a lower cost. Kaolin, talc and alumina were used as the starting materials for cordierite synthesis, and only a small amount of boric acid (H3BO3) was used as the flux. Despite the limited amount of liquid phase formed, the addition of H3BO3 could effectively promote the formation of plate-like cordierite polycrystals, which might be related to the gas-phase-mass transfer of molten boron trioxide (B2O3) at high temperatures and the selective adsorption of [BO3] on different crystal planes during crystallization. Moreover, it is necessary to closely control the calcining temperature, as the morphological development of cordierite polycrystals was sensitive to temperature. Plate-like α-cordierite polycrystals with submicron size could be obtained with the addition of 3 wt% H3BO3 at a calcining temperature of 1180 °C. This study broadens the range of complex oxides that can be obtained by the flux method and provides some references for the preparation of cordierite powder with good sinterability.

Physico-chemical features of tool wear of PCBN

The effects of physical and chemical interaction between a tool equipped with a superhard composite based on cubic boron nitride (SBNB) and the components of the material being processed and air oxygen were studied using the results of the study of model thermal activation and real thermal triboactivation of the tool contact areas in the cutting zone. It is shown that, depending on the thermobaric load, chemical interaction between the elements of the contacting materials and air oxygen is realized at the working areas of the tool: – the tool material is oxidized by air oxygen to form boric anhydride; – the metals that make up the processed material interact with boron nitride to form borides of the MeхB type; – the effect of contact-reactive melting is realized on the contact surfaces of the tool with the formation and melting of eutectics of the Me-MeхB type. The performance of a cutting tool equipped with a composite based on cubic boron nitride is limited by the chemical interaction of the tool material with the material being processed and air oxygen in the cutting zone. The cutting temperature corresponding to the formation of a liquid phase from the products of interaction on the working areas of the tool is an attractor for increasing the cutting speed.

Effect of gamma ray irradiation on optical and luminescence properties of CeO2 doped bismuth glass

High lead oxide based Radiation Shielding Window (RSW) glass is highly toxic in nature and thus health hazardous. Therefore, a new way to design environmental friendly non-toxic lead-free RSW glass for nuclear application is very much required. In this work, a lead-free non-toxic glass based on multi-component Bi2O3–BaO–B2O3–ZnO–As2O3–MgO–Na2O system has been studied with different concentrations of cerium oxide (CeO2) as doping agent for enhancing radiation shielding effect. The optical properties of cerium doped bismuth based lead-free radiation shielding glass after exposure to gamma radiation up to 105 rad have been studied. The densities of glass varied from 4.59 to 5.05 g/cc on varying concentrations of bismuth oxide and boron trioxide in glass system. The transmission properties in visible regions from 400 to 1000 nm are investigated through UV–visible spectrometer after exposure to gamma radiation on developed glass using 60Co Gamma Chamber GC5000. The structure of glass as characterized by Raman spectroscopy, XRD, Photoluminescence (PL), FESEM with EDAX, refractive index measurement and dilatometry test has been correlated with its properties. The developed bismuth glass could find its application as lead-free RSW glass in nuclear reactors as an alternative to high lead containing glass.

A novel method of enhancing valuable element recovery for ultra-high-titanium magnetite

The metallization reduction-magnetic separation process was adopted to carry out the experiments to promote the recovery ratio of valuable elements by adding diboron trioxide additive in this work. It is demonstrated that diboron trioxide has the function of destroying Si–O–Si bond for the reduction of ultra-high-titanium magnetite. The optimum experimental condition is found to be the reduction temperature of 1125 °C, the reduction time of 30min, and the diboron trioxide percent of 8 wt% for which the metallization ratio is 92%, and the recovery ratio of ferrum, vanadium, titanium is 90.9%, 78.5%, 76.1%, respectively. V and Ti are synchronously concentrated in non-magnetic materials. The phase composition transformation rule of the valuable components was Fe3O4 (FeTiO3) → FeO → Fe; FeTiO3 (→ FeTi2O5) → (Fe,Mg)Ti2O5; FeTiO3 → TiO2 → Ti3O5 → Ti2O3; (Fe3O4 + TiO2) → Fe3Ti3O10 → Fe. Increasing the temperature can promote the aggregation and growth of iron particles, but too high temperature is not conducive to the separation of Fe, V and Ti. It is evidently observed that when the temperature exceeds 1150 °C, the iron particles are closely connected with the gray titanium oxide, while at 1125 °C, the iron particles are relatively independent. Meanwhile, part of Ti is observed in silicate phase as solid-dissolved form because of high temperature and cause loss. Overall speaking, the metallization reduction-magnetic separation process with diboron trioxide as an additive has achieved the better separation of valuable components, with a higher degree of metallization, and large-scale lowered reaction temperature and time.

The effects of boron trioxide on the structure and degradation behaviour of borosilicate bioactive glass

ABSTRACT Degradation behaviour of bioactive glass (bioglass) is one of the most important factors affecting bone repair, because an excellent and controllable degradation rate can match the rate of new bone formation. In this research, the derived borosilicate bioglasses based on the 6Na2O-8K2O-8MgO-22CaO-18B2O3-54SiO2-2P2O5 component were synthesized. The effects of B2O3 on the structure, degradation behaviour and cytocompatibility of borosilicate bioglasses were systematically studied. The results showed that with B2O3 addition, the network-forming units became diversified and part of BO4 units transformed into BO3 units. These factors weakened the chemical durability of borosilicate bioglass, thus accelerating the bioglass shedding and altering the ions release, especially B. This study provides a theoretical basis for designing borosilicate bioglass with adjustable degradation rate and ion release behaviour to meet the diverse needs of clinical bone repair.

Effect of B2O3 on viscosity of high-magnesia blast furnace slag

Metallurgical companies in the Urals account for 50 – 60 % of local raw materials. Its deficit is compensated by the use of materials imported from Central Russia, the Kola Peninsula and Kazakhstan. Replacing them with the local raw materials would increase the competitiveness of metal produced in the Urals, so the question of assessing the possibility of replacing imported raw materials with local ones is very relevant. Such raw materials could be siderite ores from the Bakal deposit. They are not in demand by metallurgists because of their low iron content and high magnesium content. With growth of siderites in a charge the magnesium oxide content in slag increases that influences its viscosity and makes it difficult or impossible to smelt using more than 20 % of siderites. The use of boron oxide has been suggested to liquefy the slag. The synthetic slag containing 26.8 % CaO, 38.1 % SiO2 , 11.8 % Al2O3 , 23.6 % MgO, simulating composition of slag from MMK blast-furnace smelting with the addition of 30 % of burnt siderites is short and unstable. The temperature corresponding to the slag viscosity at the blast furnace outlet (0.5 Pa·s) is 1390 °C and the temperature corresponding to the melting point (viscosity 2.5 Pa·s) is 1367 °C. If boric anhydride is added to such a slag, it becomes long and stable. In the melts, when the proportion of B2O3 is increased from 0 to 12 %, the temperature at which the slag viscosity is 0.5 Pa·s and 2.5 Pa·s decreases to 1260 °C, and 1100 °C, respectively. This makes it possible to significantly increase the siderite content in blast furnace charge.

Non-toxic precursor for chemical vapor deposition of borophene on Cu(111) surface

In this work, conventional CVD technique, which had already been available in industries and laboratory, was proposed to utilize as an alternating method to synthesize borophene. This approach used the boron and diboron trioxide as boron source, Therefore, there was no extra cost for the toxic waste treatment. In addition, by blending their adjusted similar size into homogeneous mixture, it had demonstrated to improve the efficiency of overall process, and was able to achieve thin film layer of borophene with approximately 500 × 300 nm2 and about 3 nm thick. The metallic boron (B1s (Metal)) and crystalline systems in both single boron form (α-B) of borophene and copper-boron alloy form (β-B) were present. This report of facile borophene fabrication would potentially open up the feasibility of synthesizing methods in similar systems that will help the further application and development of 2-dimensional materials.

Application of h‐BN particles using Ca‐assisted carbothermal reduction nitridation to high‐thermal‐conductive resin/h‐BN composites

AbstractHexagonal boron nitride (h‐BN) particles exhibit high thermal conductivity and are promising fillers for resin filling. However, h‐BN particles are plate‐like particles with thermal anisotropy in the planar and thickness directions. Therefore, their applications are limited due to low thermal conductivity in the direction of the thickness of a resin sheet filled with h‐BN particles. In this study, we control the size and thickness of h‐BN particles using carbothermal reduction nitridation (CRN), which involves the carbothermic reduction of boric oxide in an N2 gas atmosphere and develop them into resin sheets. In CRN using a CaO promoter, a novel method is developed to control the shape, size, and thickness of h‐BN particles. Using h‐BN particles grown in the thickness direction, we have successfully provided resin sheets with high thermal conductivity.

Mechanical activation time of 6B2O3–13Al powder mixture vs. structure and phase composition of SHS products

The paper discusses the time of mechanical activation of the 6B2O3–13Al powder mixture affecting the self-propagating high-temperature synthesis (SHS), exothermic reaction temperature, structure, and phase composition of synthesis products. It is found that the time increase of the mechanical activation up to 180 min leads to a reduction in the average size of aluminum and boron trioxide particles down to 4.8 and 3.5 μm, respectively. Aluminum particles with boron trioxide inclusions are observed on the particle surface and inside their structure. Changes in the particle size and structure in the initial mixture components modify the SHS reaction front from chaotic to by layers. The structure of SHS products consists of the alumina layer (63–68 wt%) with aluminum dodecaboride (AlB12) particles (32–37 wt%) distributed under this layer. After 10 and 60 min of mechanical activation, acicular and elongated AlB12 particles appear in products synthesized from the 6B2O3–13Al powder mixture. Based on the data obtained, the SHS with subsequent mechanical activation is proposed for the fabrication of the Al2O3/AlB12 nanocomposite from the 6B2O3–13Al powder mixture. It is shown that after washing grinded SHS products with hydrochloric acid solution, the synthesized powder contains 100 wt% AlB12.

Optimization of Aluminum Boride Synthesis in the Self-Propagating High-Temperature Synthesis Mode to Create Waste-Free Technology

This paper is the continuation of our previous paper. In this work, we optimized the synthesis of aluminum borides by the SHS method. The purpose of the research was to develop the foundations of waste-free technology. The initial components were powders of boric anhydride (B2O3), aluminum (Al), the oxide-heating additive (KNO3), various fluxing additives, including mixed ones. The optimal ratios of the initial components for increasing the yield of aluminum boride with a high boron content and obtaining slag suitable for the production of high-alumina clinkers were determined. Studies have shown that the development of a waste-free technology for producing aluminum borides by the method of self-propagating high-temperature synthesis (SHS) is possible and yields target (alloy) and by-product (slag) products that meet the requirements for chemical and phase composition.

Biodegradable boron-containing poly(lactic acid) for fertilizers with prolonged action

A new strategy for obtaining long-acting fertilizers in the process of joint polycondensation of lactic and boric acids is presented. The article shows the effect of boric acid or boric anhydride additives in an amount of 0.1-1%wt. on the synthesis and final properties of poly(lactic acid). With increase in the amount of boric acid or boric anhydride in poly(lactic acid), polymers show higher T g and T m at approximately equal molecular weights compared to poly(lactic acid) without additives. Comprehensive studies of the structure of the obtained compositions were carried out: theoretical calculations using method DFT (Becke-Lee-Yang-Parr) and experimental - proton NMR, IR spectroscopy and melt rheometry. It has been suggested that the addition of boric acid when heated promotes the formation of B-O-C bonds and the branching of lactic acid oligomer chains. The compositions and the dynamic of boric acid release by granules obtained from boron-containing poly(lactic acid) melts were studied using elemental analysis for aqueous systems. During 7 days of testing in aqueous medium, the granules lose from 16 to 72% of boric acid. This study can serve as further development of the use of low-molecular-weight poly(lactic acid) with different molecular weights in the design of long-acting fertilizers. • Boric acid and boric anhydride were added to a lactic acid during synthesis of poly(lactic acid); • The effect of additives on the thermophysical, molecular-mass and rheological properties of poly(lactic acid) is estimated; • B-O-C bonds are not preserved in polycondensation products; • The results of hydrolysis indicate a prospect of using boric acid-containing poly(lactic acid) as a slow-release fertilizer.

Engineering Nanostructured Interfaces of Hexagonal Boron Nitride-Based Materials for Enhanced Catalysis.

ConspectusHexagonal boron nitrides (h-BNs) are attractive two-dimensional (2D) nanomaterials that consist of alternating B and N atoms and layered honeycomb-like structures similar to graphene. They have exhibited unique properties and promising application potentials in the field of energy storage and transformation. Recent advances in utilizing h-BN as a metal-free catalyst in the oxidative dehydrogenation of propane have triggered broad interests in exploring h-BN in catalysis. However, h-BN-based materials as robust nanocatalysts in heterogeneous catalysis are still underexplored because of the limited methodologies capable of affording h-BN with controllable crystallinity, abundant porosity, high purity, and defect engineering, which played important roles in tuning their catalytic performance. In this Account, our recent progress in addressing the above issues will be highlighted, including the synthesis of high-quality h-BN-based nanomaterials via both bottom-up and top-down pathways and their catalytic utilization as metal-free catalysts or as supports to tune the interfacial electronic properties on the metal nanoparticles (NPs). First, we will focus on the large-scale fabrication of h-BN nanosheets (h-BNNSs) with high crystallinity, improved surface area, satisfactory purity, and tunable defects. h-BN derived from the traditional approaches using boron trioxide and urea as the starting materials generally contains carbon/oxygen impurities and has low crystallinity. Several new strategies were developed to address the issues. Using bulk h-BN as the precursor via gas exfoliation in liquid nitrogen, single- or few-layered h-BNNS with abundant defects could be generated. Amorphous h-BN precursors could be converted to h-BN nanosheets with high crystallinity assisted by a magnesium metallic flux via a successive dissolution/precipitation/crystallization procedure. The as-fabricated h-BNNS featured high crystallinity and purity as well as abundant porosity. An ionothermal metathesis procedure was developed using inorganic molten salts (NaNH2 and NaBH4) as the precursors. The h-BN scaffolds could be produced on a large scale with high yield, and the as-afforded materials possessed high purity and crystallinity. Second, utilization of the as-prepared h-BN library as metal-free catalysts in dehydrogenation and hydrogenation reactions will be summarized, in which they exhibited enhanced catalytic activity over the counterparts from the previous synthesis method. Third, the interface modulation between metal NPs with the as-prepared defects' abundant h-BN support will be highlighted. The h-BN-based strong metal-support interaction (SMSI) nanocatalysts were constructed without involving reducible metal oxides via the ionothermal procedure we developed by deploying specific inorganic metal salts, acting as robust nanocatalysts in CO oxidation. Under conditions simulated for practical exhaust systems, promising catalytic efficiency together with high thermal stability and sintering resistance was achieved. Across all of these examples, unique insights into structures, defects, and interfaces that emerge from in-depth characterization through microscopy, spectroscopy, and diffraction will be highlighted.

Reinforced via the insulative boric oxide in the BaTiO3 amorphous thin film with high energy storage capability and stability

Dielectric film capacitors are considered as a potential candidate for advanced power electronics technology due to their fast charging and discharging rate and stability. However, the further improvement of energy storage density is still a major challenge. Herein, a reasonable amorphous structure is applied to the preparation of dielectric film capacitors to improve the dielectric and energy storage properties. The high breakdown strength and energy storage density in the amorphous film are assigned by the disordered structure and intrinsic high insulative for B2O3. As a result, a high discharge energy storage density of 68.64 J cm−3 and an efficiency of 85% can be achieved in the BaTiO3-5wt%B2O3 amorphous thin film at 7.3 MV cm−1, together with excellent thermal stability (20–200 °C) and cyclic stability (up to 105 times) This work provides a paradigmatic method to achieve high energy storage density and stability.

B2O3 reinforced polylactic acid/thermoplastic polyethylene glycol shape memory composites

AbstractRecently, there has been a great demand for boron‐containing compounds (BCCs) with unique biological properties. The demand for the use of these compounds not alone but as additives in composite materials is increasing day by day. In this study, the effect of adding B2O3 compound to the blend of PLA and PEG polymers, which is an important biocompatible shape memory polymer, was investigated. In order to examine the effect of increasing B2O3 additive on the thermal properties of PLA‐PEG blend, it was determined by using a Differential Scanning Calorimetry (DSC) and thermogravimetric analyzer (TGA), and it was seen that while the melting temperature of PEG decreased, the melting temperature of PLA increased. In addition, when the thermal stability of the composites was examined, increasing of thermal stability was observed with the addition of B2O3 and a three‐step degradation occurred. It was determined that the B2O3/PLA‐PEG composite was homogeneous by taking X‐ray measurements and SEM measurements. The antimicrobial property of the PLA‐PEG blend improved with the increasing B2O3 contribution were observed from the antimicrobial activity measurements of the composite against 4 different bacteria. However, it was determined that the PLA‐PEG blend preserved its shape memory effect with increasing diboron trioxide contribution.

Electrochemical deposition of nickel from local nickel sulphate solution on copper substrate

In this work, nickel was deposited on copper substrate through electrodeposition which was abstracted from local sulphate salt. Nickel deposition on copper substrate was done in both presence of vitamin C and saccharin additive. Boric oxide was used as buffering agent and pH of the solution bath was maintained through sulfuric acid and ammonium hydroxide. Round shape deposition on copper substrate was observed in the presence of vitamin C, while columnar shape particles were observed in the presence of saccharin additive. Deposition of nickel was done through sulfate bath on copper substrate. Boric acid was used as buffering agent and direct current electrolysis were conduct throughout this experimental work. pH of the solution was kept constant with the help of diluted sulfuric acid and ammonium hydroxide. The deposited nickel particles were obtained in round shape in the presence of vitamin additive, while columnar shape particles obtained in saccharin additive. The experimental conditions were optimizing to get smooth, adherent, and acid resistance surface. This research work reported that, rate of sulfate bath deposition increases lineally with increase in temperature and pH of the solution.

Kinetics of the Synthesis of Aluminum Boride by the Self-Propagating High-Temperature Synthesis Method

The influence of certain factors on the kinetics of the process of obtaining aluminum borides (burning rate, ingot formation, and phase separation) was investigated. In this study, we report the registration of diboride using the SHS protocol. The synthesis of aluminum diboride from boric anhydride occurred by the aluminothermic method. The initial components were boron trioxide and aluminum in the form of powders. Researchers paid special attention to the degree of grinding of the charge fluxing substances. The influence this had on the rate of development of the degree of charge concentration was studied. To calculate the degree of charge, a composition was chosen according to the speed obtained from a number of experiments where melting was carried out with the following charge densities in g/cm3: 0.80; 1.08; 1.18; 1.74. The method of melting was ignition from above. The experimental results allowed us to conclude that the nature of the change in the combustion rate of the system, where there was an excess of the reducing agent in the charge, is the same. An increase in the combustion rate, where there was an excess of aluminum of up to 20%, was likely due to the fact that the reaction area of the charge components increased. In addition, an increase in speed can be explained by a decrease in heat losses due to a reduction in the melting time. With an increase in excess aluminum above 20% of the stoichiometry, the observed decrease in the combustion rate can be explained by a decrease in the specific heat of the process due to the melting of the excess aluminum, which played the role of a ballast.

Exposure to boron trioxide nanoparticles and ions cause oxidative stress, DNA damage, and phenotypic alterations in Drosophila melanogaster as an in vivo model.

Boron trioxide nanoparticles (B2 O3 NPs) have recently been widely used in a range of applications including electronic device technologies, acousto-optic apparatus fields, and as nanopowder for the production of special glasses. We propose Drosophila melanogaster as a useful in vivo model system to study the genotoxic risks associated with NP exposure. In this study, we have conducted a genotoxic evaluation of B2 O3 NPs (size average 55.52 ± 1.41 nm) and its ionic form in D.melanogaster. B2 O3 NPs were supplied to third instar larvae at concentrations ranging from 0.1-10mM. Toxicity, intracellular oxidative stress (reactive oxygen species, ROS), phenotypic alterations, genotoxic effect (via the wing somatic mutation and recombination test, SMART), and DNA damage (via Comet assay) were the end-points evaluated. B2 O3 NPs did not cause any mutagenic/recombinogenic effects in all tested non-toxic concentrations in Drosophila SMART. Negative data were also obtained with the ionic form. Exposure to B2 O3 NPs and its ionic form (at two highest concentrations, 2.5 and 5mM) was found to induce DNA damage in Comet assay. Additionally, ROS induction in hemocytes and phenotypic alterations were determined in the mouths and legs of Drosophila. This study is the first study reporting genotoxicity data in the somatic cells of Drosophila larvae, emphasizing the importance of D. melanogaster as a model organism in investigating the different biological effects in a concentration-dependent manner caused by B2 O3 NPs and its ionic form. The obtained in vivo results contribute to improvement the genotoxicity database on the B2 O3 NPs.

Investigation of the Role of Calcium Borate in the Growth of Hexagonal Boron Nitride Particles

Hexagonal boron nitride (h-BN) powder is a promising thermally conductive filler in resins and controlling its particle size is important. To obtain h-BN powder with a large particle size as well as high purity and crystallinity, high-temperature heat treatment over 1800 oC in N2 gas atmosphere is effective. Carbothermal reduction nitridation (CRN) involves carbothermic reduction of boric oxide in N2 gas atmosphere. In CRN using a CaO promoter, h-BN particles with large sizes can be produced through a simple heat-treatment process. During CRN, CaO forms calcium borate (CaO-B2O3), which prevents the vaporization of B2O3 and promotes h-BN particle growth at high temperatures. Up to now, the effect of CaO-B2O3 on the growth of h-BN particles during CRN is unclear. In this study, the role of CaO-B2O3 in the growth of h-BN particles during CRN was clarified via experimentation using various approaches. The results led to the ideal reaction process of CRN using a CaO promoter to produce large-particle-size h-BN powder.

Probing the chemical reactivity of the B2O3 -I (1 0 1) Surface: Interaction with H2O and H2S

Diboron trioxide is of interest because of its unique unreactive functionality properties. In this work we have studied – via computational first-principle techniques - the adsorption and dissociation mechanisms of two hydrogen chalcogenides, namely water (H2O) and hydrogen sulfide (H2S) molecules, over the B2O3 -I (101) surface. We show that the water molecules undergo dissociative adsorption over diboron via an activation energy of 39 kJ/mol. Furthermore, desorption of both molecularly adsorbed and dissociated structures of water molecules from the B2O3 -I (101) surface requires activation energies of 124–127 kJ/mol. Our investigation on the other hydrogen-chalcogenide compound, i.e. H2S, reveals that diboron trioxide attracts H2S molecules and forms molecular adsorption via sp3 hybridisation between the lone pair electron of the H2S and the empty p orbital of the Bsurf atom without encountering an activation barrier. However, the energy barrier required to dissociate H2S over the B2O3 -I (101) surface appears exceedingly high at 310 kJ/mol. The present insight resolves the two different behaviours of B2O3 concerning hydrogen chalcogenides reported in the literature. While acting as a water scavenger to generate dissociated radicals, it exhibits an inhibitor characteristic towards the dissociation of H2S molecules, representing an ideal reactor wall coating for desired pure gas phase reactions.

Calculated substantiation of isolation of boron and sodium cations from molten working and heating medium during hardening of restored parts

Scientific and technological research in the development of the technical process for the restoration and strengthening of worn parts using calculated justification allowed us to make an optimal technical decision on the development of a method for surfacing and electrolysis borating of parts to increase their service life. The working medium for strengthening the restored tillage organs of agricultural aggregates is substantiated theoretically using the developed mathematical model describing the working medium as a thermodynamic system consisting of boron cations, sodium and oxygen anions. The creation of a potential difference in this medium will provide a process in which boron and sodium ions are discharged at the cathode, and oxygen ions at the anode. For this, it is necessary to theoretically determine the electromotive forces of polarization of electrolytic cells and compare them. The solution to this problem requires an assessment of the change in the Gibbs energy during the decomposition of sodium oxide and boric anhydride for the temperature of the borating process, taking into account its change under standard conditions, the chemical potentials of the reacting components and phase transitions, the melting of substances and their sublimation. The order in which boron and sodium are separated at the cathode is determined by comparing the electromotive forces of polarization of boric anhydride and sodium oxide. It was found that sodium oxide is more stable than boric anhydride. Consequently, boron atoms are reduced on the cathode surface, and calculations have confirmed the possibility of its use.