Borate Hydroxide Research Articles

Improved thermal stability and flame retardancy of soybean oil-based polyol rigid polyurethane foams modified with magnesium borate hydroxide and ammonium polyphosphate

The concept of sustainable development has led to a growing research interest in bio-based flame-retardant polyurethane foams. These foams offer environmentally friendly, sustainable, and flame-retardant raw materials for the construction, automotive, and furniture industries. The 15 wt% soybean oil-based polyol rigid polyurethane foams (RPUF-S3A20B system) were modified with 20 wt% ammonium polyphosphate (APP) and homemade magnesium borate hydroxide (MgBO2(OH)). Thermogravimetric analysis, pyrolysis kinetic analysis, limiting oxygen index (LOI) test, cone calorimetry (CONE), morphological analysis, and smoke density (Ds) were employed to investigate the impact of MgBO2(OH) on the thermal stability and flame-retardant properties of the RPUF-S3A20B system. The results indicated that RPUF-S3A20B12.5 with 12.5 wt% MgBO2(OH) had better thermal stability and higher activation energy. In addition, its LOI was increased by 3.1% compared to RPUF-S3A20 without MgBO2(OH). The peak heat release rate (PHRR) and total heat release rate (THR) of RPUF-S3A20B12.5 at a radiant flux of 25 kW/m2 were reduced by 45.8% and 35.0% compared with RPUF-S3A20. RPUF-S3A20B12.5 demonstrated the lowest smoke density (17.4 and 17.5) and highest light transmission (73.9% and 73.7%) in both flameless and flame conditions, indicating superior flame-retardant and smoke-suppression properties. These findings offered valuable insights for further research on synergistic flame-retardant systems in bio-based polyurethane foams.

Ulexite/HDPE-Bi2O3/HDPE layered composites for neutron and gamma radiation shielding

In this study, 5, 10, and 15 wt% ulexite (NaCaB5O6(ΟH)6·5H2O, hydrated sodium calcium borate hydroxide) and 15 wt %Bi2O3 filled high density polyethylene (HDPE) composite materials were fabricated through conventional melt-extrusion processing techniques in the form of a layered structure in order to absorb both neutron radiations and the secondary radiations resulting from neutron induced reactions. In the layered structure, HDPE was used to slow down neutrons, while ulexite and Bi2O3 were used to capture thermal neutrons and secondary gamma radiations, respectively. The properties of ulexite/HDPE and Bi2O3/HDPE composites were investigated through scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA). The mechanical properties (tensile and hardness) of composite materials were also investigated. The results showed that the addition of ulexite and Bi2O3 particles does not change the thermal and mechanical properties of the HDPE composites significantly. Total macroscopic cross-section of the composites was determined using a 239Pu–Be (α,n) neutron source, while their linear and mass attenuation coefficients were determined using a137Cs gamma-ray source. The results show that ulexite filled HDPE composites enhance neutron shielding property and Bi2O3 filled HDPE composites provide good shielding performance for gamma rays.

Enhanced wear resistance while maintaining transparency of epoxy resin coatings filled with novel one-dimensional magnesium borate hydroxide nanorods

Wear resistance and transparency are critical properties of polymer coatings. In this study, a novel nanocoating filler composed of one-dimensional inorganic magnesium borate hydroxide (MBH) nanorods was used to improve the wear resistance and transparency of epoxy resin (EP) coatings. After successfully synthesizing MBH nanorods, different amounts were added to EP coatings to prepare EP/MBH nanocomposites, denoted as ExMBH (x = 1, 5, and 10 wt% MBH). The transparency and wear resistance of the neat and MBH-filled EP coatings were estimated using optical transmittance and nanoscratch testing, respectively. The results indicate that E10MBH displays a transmittance of more than 85 % in the visible region and a low value in the UV region, resulting from the similar refractive indices of the MBH filler and EP. Additionally, the scratch recovery index and scratch hardness increase by 53 % and 22 %, respectively, while the plastic deformation energy decreases by 67 % compared to that of the neat EP coating. The E10MBH nanocoating presents excellent wear resistance due to the formation of a solid three-dimensional network structure between EP and MBH. This paper demonstrates an effective strategy for designing inorganic nanofillers to improve the mechanical durability and optical properties of EP nanocoatings.

Comments on the paper “Synthesis and characterization of inorganic nonlinear optical material: Potassium sodium hydroxide borate hydrate (KSB) single crystal”

The authors of the title paper (Mater. Lett. 188 (2017) 156–158) claimed to have grown potassium sodium hydroxide borate hydrate (KSB) single crystal and reported its mechanical properties in a subsequent paper (Mater. Lett. 215 (2018) 165–168). In this letter, many points of criticism concerning the crystal growth, structure characterization and interpretation of the spectral and thermal data of the so-called KSB crystal are described to prove that it is a dubious material.

Reply to “Comment on the paper “Synthesis and characterization of inorganic nonlinear optical material: Potassium sodium hydroxide borate hydrate (KSB) single crystal”

The authors of the title paper (Mater. Lett. 188 (2017) 156–158) has grown potassium sodium hydroxide borate hydrate (KSB) I single crystal using slow evaporation method. In this letter, crystal growth, unit cell measurement, FTIR and thermal analysis are described in order to prove that the grown single crystal (KSB) is a trustworthy material.

Surface-diffusion mechanism for synthesis of substrate-free and catalyst-free boron nitride nanosheets

This study presents an innovative surface-diffusion mechanism for the growth of substrate-free and catalyst-free boron nitride nanosheets (BNNSs) by annealing an ammonium borate hydroxide hydrate precursor in a NH3 chemical vapor deposition system. At elevated temperatures, part of NH4B5O8 slowly decomposes and forms B2O3, and flowing NH3 gradually diffuses to the B2O3 surface to form vertically aligned BNNSs. The lateral dimension and crystallinity of the BNNSs increase, while their thickness decreases with the continuous surface-diffusion reaction. The residual NH4B5O8 and B2O3 absorbs moisture in the air to constitute NH4B5O8·4H2O and H3BO3 substrates. With increasing annealing temperature and soaking time (at 1400 °C for 7 h), all NH4B5O8 decomposes and the surface-diffusion reaction between B2O3 and NH3 completely occurs, forming substrate-free BNNSs with a lateral dimension of 1 μm and a thickness of 10 nm. This reliable approach for synthesizing BNNSs paves the way for future applications in advanced ceramic composites.

Layered double hydroxide–borate composites supported on magnetic nanoparticles: preparation, characterization and molecular dynamics simulations

Magnetic nanocomposites involving tetraborate ion (TB)-intercalated Mg–Al-layered double hydroxide (LDH) shell supported on magnesium ferrite core particles are synthesized, characterized, and compared with their non-magnetic analogues. The compositions of the obtained nanocomposites were determined and structural investigations were made by powder X-ray diffraction and Fourier transform infrared spectroscopy. Particle characteristics were examined by size distribution, specific surface area measurements, scanning electron microscopy and transmission electron microscopy. Room-temperature magnetic measurements were performed with a vibrating sample magnetometer. The dynamics and structure of the interlayer water molecules and borate ions were studied by molecular dynamics simulations. Analytical and modeling studies verified that the TB ions were arranged between the LDH layers in oblique positions. The products were found to carry ca. 6% boron (1017 B atom/μg nanocomposite). The magnetic nanocomposite showed superparamagnetic properties and can potentially find applications in biomedical fields for the site-specific delivery of bio-potent boron agents.

Study on the mechanical properties of potassium sodium hydroxide borate hydrate (KSB) single crystals by using Vickers microhardness tester

The mechanical properties of solution grown potassium sodium hydroxide borate hydrate single crystal (KSB) have been obtained by using Vickers microhardness studies in the load range from 10 to 70 g. The variation of microhardness with load represents the load independent value of hardness (Indentation size effect). The meyer’s index number ‘n’ is calculated as 1.81 and it belongs to soft material category. Various mechanical parameters such as yield strength, elastic stiffness constant, fracture toughness, brittleness index, hardness contour and crack propagation of KSB single crystal are discussed in detail.

Front Cover: Structure Elucidation and Characterization of the High‐Pressure Nickel Borate Hydroxide NiB3O5(OH) (Z. Anorg. Allg. Chem. 21/2017)

Front Cover: Structure Elucidation and Characterization of the High‐Pressure Nickel Borate Hydroxide NiB₃O₅(OH) (Z. Anorg. Allg. Chem. 21/2017)

Structure Elucidation and Characterization of the High‐Pressure Nickel Borate Hydroxide NiB3O5(OH)

The high‐pressure nickel borate hydroxide NiB3O5(OH) was synthesized in a high‐temperature/high‐pressure reaction at 4 GPa and 1023 K using a Walker‐type multianvil apparatus. Single‐crystal X‐ray diffraction was used to determine the structure of NiB3O5(OH). It crystallizes in the monoclinic space group P21/c (no. 14) with a = 4.3222(1), b = 9.5888(2), c = 8.5067(3) Å, and β = 90.50(1)°. Furthermore, the compound was characterized by powder X‐ray diffraction, vibrational spectroscopy, and magnetic measurements. The effective magnetic moment is μeff = 3.30(1) μB and the Weiss constant θP = –28.3(1) K indicates antiferromagnetic interactions in the paramagnetic regime.

Beaver-dam-like membrane: A robust and sulphifilic MgBO2(OH)/CNT/PP nest separator in Li-S batteries

The assembly of various low dimensional nanomaterials into hierarchical nanostructures is a central issue since it inherits the advantages of each component and even leads to the formation of advanced materials with unforeseen properties. The rational integration of nanomaterials into an effective membrane is expected to regulate the complex energy chemistry of lithium–sulfur (Li–S) batteries. In this contribution, a bio-inspired beaver-dam-like membrane was proposed as a robust and sulphifilic nest separator for advanced Li–S cells. The nest separator was integrated by a continuous polypropylene, a highly electrical conducting network of carbon nanotubes (CNTs), and lithium polysulfide (LiPS)-suppressing adsorbents of magnesium borate hydroxide (MBOH) nanofibers to enhance the redox reaction of LiPS intermediates and retard their migration in a working cell. The kinetic behavior of LiPS conversion on sulphifilic surface was well understood through direct measurements of lithium sulfide nucleation and potentiostatic discharge profiles, demonstrating the interfacial affinity between MBOH and LiPS. The smart hybridization of MBOH and CNTs in nest separators rendered the Li–S cell with long cycling stability of 785mAhg−1 after 200 cycles, high rate capability of 500mAhg−1 at 6C, enhanced areal capacity of 2.91mAhcm−2, and improved thermal stability. The presented bio-inspired design sheds fresh light on a novel electrolyte system to demonstrate the superb electrochemical performances of Li–S batteries and affords new insights into understanding the interfacial interaction between LiPS and adsorbents.

Synthesis and characterization of inorganic nonlinear optical material: Potassium sodium hydroxide borate hydrate (KSB) single crystal

Using the slow evaporation solution growth technique, a new compound of potassium sodium hydroxide borate hydrate (KSB) single crystal has been prepared. The title compound crystallized in a noncentrosymmetric hexagonal system with P6¯2c space group was confirmed by single crystal X-ray diffraction. The functional group was determined by using FTIR spectrum. The absorption spectrum shows an absorption edge at 265nm with a band gap of 4.68eV. The melting point of the material was found to be 105°C using TG/DSC analysis. The frequency dependence of dielectric, ac conductivity and the relaxation of an ionically conducting crystal have been studied for different temperatures. Nonlinear optical measurement of the grown crystal can displays a SHG response which is almost equivalent to that of KDP.

In-vacuum thermolysis of ethane 1,2-diamineborane for the synthesis of ternary borocarbonitrides

High-temperature (1000 °C) thermolytic decomposition of ethane 1,2-diamineborane (BH3NH2CH2CH2NH2BH3) deposited onto a Cu foil has been performed in an ultra-high-vacuum environment. A combined thermolytic, structural (x-ray diffraction), microscopic (scanning electron microscopy) and spectroscopic (Raman, x-ray photoemission spectroscopy) analysis, has identified a ternary borocarbonitride (BCN) compound as a result of the process. The obtained BCN compound is nanocrystalline, surrounded by crystallites of ammonium hydroxide borate hydrate. The ternary compound presents a 0.2:0.6:0.2 B:C:N composition in the bulk and 0.11:0.76:0.13 stoichiometry at the very surface, richer in C–C networks with respect to the bulk. Furthermore, the resulting BCN compound does not show oxidation at the surface due to the in-vacuum thermolysis of the single precursor.

One-dimensional manganese borate hydroxide nanorods and the corresponding manganese oxyborate nanorods as promising anodes for lithium ion batteries

Novel manganese and boron containing nanomaterials have been investigated for applications in rechargeable lithium ion batteries (LIBs) in recent years owing since they are more environmentally-benign and more abundant in nature than the materials currently employed. In this study, one-dimensional (1D) Mn3B7O13OH nanorods and MnBO2OH nanorod bundles were controllably fabricated by using NH4HB4O7 and Mn(NO3)2 as reagents via a hydrothermal or solvothermal process, respectively, without any surfactants or templates at 220 °C. It is interesting to find that both materials are transformed into Mn2OBO3 nanorods/nanorod bundles by subsequent calcination. The formation processes of the above 1D borate containing products were investigated and the as-obtained four kinds of borates were studied as novel anode materials. It was found that the Mn2OBO3 nanorods displayed the best performance among the four borates, delivering an initial discharge capacitiy of 1,172 mAh·g−1 at 100 mA·g−1, and 724 mAh·g−1 could be retained after 120 cycles. A full battery composed of a Mn2OBO3 nanorod anode and a commercial LiFePO4 (or LiCoO2) cathode has also been assembled for the first time, which delivered an initial discharge capacity of 949 mAh·g−1 (779 mAh·g−1 for LiCoO2). The excellent cycle and rate performances of the products reveal their potential applications as anodes for LIBs.

Evaluation of Colemanite against Wood-Destroying Insects

Colemanite is hydrated calcium borate hydroxide and a borate mineral found in evaporate deposits of alkaline lacustrine environments. It is a secondary mineral that forms by alternation of borax and ulexite. As this chemical is less toxic to human beings and other organisms, it was chosen to assess its efficacy against various wood destroying insects. Colemanite at 1% concentration is the lethal dose found in the present investigation to make plywood free from wood destroying insects. In India, this is the first report where colemanite is used in the preservation of plywood.

Flame Retardancy Research of Rubber Powder Modified Asphalt

Based on the tunnel pavement flame retardantcy requirement, flame retardant is added into rubber powder modified asphalt, and then study the flame retardant performance.For flame retardant we chose Decabromodiphenyl ethane instead of decabromodiphenyl ether, silicon is dimethyl silicone oil of flame retardant ,which can improve the flame retardant material performance,we also choose the zinc borate and aluminum hydroxide, through the orthogonal experiment and gray relational analysis method, fire retardant best species composition and dosage level is concluded.

Ulexite-galena intermediate-weight concrete as a novel design for overcoming space and weight limitations in the construction of efficient shields against neutrons and photons

Recently, due to space and weight limitations, scientists have tried to design and produce concrete shields with increased attenuation of radiation but not increased mass density. Over the past years, the authors' had focused on the production of heavy concrete for radiation shielding, but this is the first experience of producing intermediate-weight concrete. In this study, ulexite (hydrated sodium calcium borate hydroxide) and galena (lead ore) have been used for the production of a special intermediate-weight concrete. Shielding properties of this intermediate-weight concrete against photons have been investigated by exposing the samples to narrow and broad beams of gamma rays emitted from a ⁶⁰Co radiotherapy unit. Densities of the intermediate-weight concrete samples ranged 3.64-3.90 g cm⁻³, based on the proportion of the ulexite in the mix design. The narrow-beam half-value layer (HVL) of the ulexite-galena concrete samples for 1.25 MeV ⁶⁰Co gamma rays was 2.84 cm, much less than that of ordinary concrete (6.0 cm). The Monte Carlo (MC) code MCNP4C was also used to model the attenuation of ⁶⁰Co gamma-ray photons and Am-Be neutrons of the ulexite-galena concrete with different thicknesses. The ⁶⁰Co HVL calculated by MCNP simulation was 2.87 cm, indicating a good agreement between experimental measurements and MC simulation. Furthermore, MC-calculated results showed that thick ulexite-galena concrete shields (60-cm thickness) had a 7.22 times (722 %) greater neutron attenuation compared with ordinary concrete. The intermediate-weight ulexite-galena concrete manufactured in this study may have many important applications in the construction of radiation shields with weight limitations such as the swing or sliding doors that are currently used for radiotherapy treatment rooms.

Efficacy of colemanite against mould fungi on rubber wood veneer

Colemanite, also called as hydrated calcium borate hydroxide, is a borate mineral found in evaporite deposits of alkaline lacustrins environments. It is a secondary mineral that forms by alternation of borax and ulexite. As this chemical is not toxic to human beings and other mammals, it has been chosen for the present preliminary work on assessing the efficacy against mould fungi on rubber wood veneers. Colemanite at two different levels of concentrations, 3 and 5 % was tested against moulds and it has been found that 5 % concentration acts as an effective mouldicide. In India this is the first report where colemanite was used against mould fungi.

Preparation of Magnesium Borate Nanomaterials by Hydrothermal Route

Magnesium borate ball of wires, nanowires and petaliforms were prepared via calcination of magnesium borate hydroxide synthesized by hydrothermal route. Results of SEM characterization indicated that the morphology of magnesium borate hydroxide and magnesium borate could be talored via varying reaction temperature, reaction time and water's volume. And pure magnesium borate could be achieved when magnesium borate hydroxide was calcinated at 700°C.

Hydrothermal Synthesis of MgBO<sub>2</sub>(OH) Nanomaterials

Magnesium borate hydroxide (MgBO2(OH) ) were synthesized using magnesium nitrate hexahydrate(MgNO3.6H2O) and borax decahydrate(Na2B4O7.10H2O) by hydrothermal route. Effect of reaction temperature , reaction time and water's volume on the composition , structure , and crystal morphology of the products were investigated, and the products were characterized by XRD and SEM. The results indicated that all of the products were szaibelyite with the reaction condition investigated, and crystal morphology could be tailored via varying the reaction condition.