Trimethyl Borate Research Articles (Page 1)

Integration of an electron beam ion trap source into an electrostatic accelerator for pre-clinical cancer research.

Trimethyl borate assisted chemoselective synthesis 1,5-dihydrodiazepines from hemicurcuminoids and o-phenylenediamines

Borate and its fluorination, as an electrolyte additive or solvent, have been proven to enhance electrochemical performance in high-voltage lithium-ion batteries and lithium metal batteries. However, there is a research gap in the comparison of borates with and without fluorination. In light of the above-mentioned research gap, quantum chemical calculations were employed to evaluate traditional solvents─ethylene carbonate (EC), methyl ethyl carbonate (EMC), trimethyl borate (TMB), and triethyl borate (TEB)─and 19 fluorinated borates designed from TMB and TEB (named TMB- and TEB-group fluorides) in this work, and the following results were obtained. First, as the number of F atoms increases, the oxidation resistance of the molecule is enhanced. Moreover, when the number of F atoms is the same, molecules with an evenly distributed fluorination across the three side chains exhibit greater oxidation resistance than those with fluorination concentrated in a single side chain. Meanwhile, we compared the oxidation potentials of each fluorinated molecule with that of the solvent EC (whose oxidation potential is higher than that of EMC). Molecules with lower oxidation potentials than EC were considered as additives, while those with higher oxidation potentials were regarded as solvents or diluents. Subsequently, we evaluated the application potential of each molecule across different dimensions. Second, we screened 13 molecules suitable as additives across six dimensions: binding energy with O2-, HF, F-, Li+; LUMO (lowest unoccupied molecular orbital)-HOMO (highest occupied molecular orbital) energy gap; and the binding energy of decomposition products with Li+. TEB_23 (the structure is presented in Supporting Information) showed the greatest potential as an additive. Third, we evaluated and compared eight molecules as normal diluents or polarity diluents using four dimensions: the LUMO-HOMO energy gap, binding energy with Li+, dipole moment (only for polarity diluents), and minimum electrostatic potential. The result has showed that TMB_333 (the structure is presented in Supporting Information) showed the greatest potential as a normal diluent, while TMB_222 (the structure is presented in Supporting Information) showed the greatest potential as a polarity diluent. This work emphasizes the significance of the appropriate number and position of fluorine substitutions in borates and provides a practical strategy for improving the performance of various high-voltage lithium-ion batteries and lithium metal batteries.

ABSTRACT In this study, the reaction kinetics of ulexite with CO2 in methanol were investigated in a pressurised reactor for the synthesis of trimethyl borate (TMB). The experimental parameters were varied as follows: temperature (T), 40–100 °C; solid-to-liquid ratio (SL), 0.05-0.2 g/mL; reaction time (t), 10–120 min; pressure (P), 10–30 bar; particle size (PS) 63–180 µm; stirring speed (SS), 500–750 rpm. The results indicated that the dissolution rate increased with higher reaction temperatures and pressures, but decreased with larger particle sizes and higher solid to liquid ratio. However, stirring speed had no significant effect on the dissolution rate. It was observed that CaCO3 crystals that formed on the surface of the solid during the reaction, inhibiting the dissolution of the mineral. Calcium carbonate was produced in the aragonite phase without the use of additives. Thus, a method has been proposed to utilise CO2 and sequester it in a stable and permanent manner. In this study, a novel production process for trimethyl borate (TMB) was investigated, and the reaction mechanism was elucidated. A comprehensive analysis of the reaction mechanism related in the TMB synthesis process were obtained. For kinetic analysis, various empirical models were applied to fit the experimental data. Scanning Electron microscopy (SEM) and X-Ray diffraction (XRD) analyses were performed on the solid sample remaining after dissolution, and the results were supported by statistical analysis. The reaction rate was found to best described by the Avrami model. The activation energy of this process was calculated as 21 kJ/mol.

Proteomic evaluation of borosilicate hybrid sol-gel coatings with osteogenic, immunomodulatory and antibacterial properties.

CO₂-Enhanced Synthesis of Trimethyl Borate from Ulexite: Innovations in Pervaporation Separation

Total syntheses of borolithochromes H1, H2, I1, and I2, the red pigments isolated from fossils of Jurassic putative red alga Solenopora jurassica, have been achieved. The naphthoquinone possessing a chiral sec-butyl side chain has been synthesized from (S)-2-methylbutanol. The Diels-Alder reaction of the chiral naphthoquinone and the previously reported diene was followed by one pot S-methylation/intramolecular Corey-Chaykovsky reaction/epoxide rearrangement to provide the benzo[gh]tetraphene skeleton. Complexation of the resulting ligand with trimethyl borate and the following O-demethylation furnished a 1:1 mixture of borolithochromes I1 and I2, which were separated by HPLC using CHIRALPAK IC® to afford optically pure borolithochromes I1 (6) and I2 (7). On the other hand, borolithochromes H1 and H2 were not separated by HPLC in our laboratory. Fortunately, the mixture of the methyl ethers of borolithochromes H1 and H2 were separated and O-demethylation with magnesium iodide furnished optically pure borolithochromes H1 (4) and H2 (5).

Abstract This paper presents the results of neutron detection efficiency and dosimetry between a borated centrifugally tensioned metastable fluid detector (B-CTMFD) configured to detect thermal to fast neutrons versus two widely used neutron detection devices of similar form factors: moderated He-3 based Ludlum-42-49B neutron detector, and, the Fuji Electric's NSN3TM (NNSN3) pressurized nitrogen-methane filled neutron detector. The one-on-one performance comparisons were conducted using soft (Cf-252 fission) neutron spectrum isotope neutron sources positioned behind various levels of lead and concrete shielding ranging in thickness from 0 cm (unshielded) to up to 30 cm. The comparisons were conducted with Monte Carlo N-Particle transport code (MCNP) code simulations to account for three-dimensional effects and to relate the absolute detection rate with the dose rate—to derive the sensitivity factor (cpm/μSv/h). While the Ludlum 42-49B and NSN3 detectors operate at a fixed sensitivity setting, the centrifugally tensioned metastable fluid detector (CTMFD) can be (and was) operated to detect and separate the contributions from epithermal (0.02 eV–0.2 MeV) and from fast (>0.2 MeV) neutrons at various sensitivity levels by varying the tensioned metastable negative pressure (Pneg) from 0.3 MPa to 0.7 MPa. The B-CTMFD (configured for detecting the full 0.02 eV to 12 MeV neutrons >0.1 MeV neutron detection at Pneg = 0.7 MPa) offered relative sensitivity enhancements of up to ∼22× greater than Ludlum and over 5× greater than NSN3, over the 0-15 cm range of Pb shielding, and the 0–30 cm concrete shield thickness. The contribution from detecting down scattered neutrons increases with increased thickness, especially for concrete shielding. The B-CTMFD design overcomes the detection penalty (up to 60% depending on shielding type and thickness) inherent in the nonborated centrifugally tensioned metastable fluid detector (NB-CTMFD), designed only to detect fast-energy neutrons—as described in the companion (Part-1) paper. However, unlike the NB-CTMFD, which used 100% decafluorapentane (DFP) (C5H2F10), the B-CTMFD requires the use of an azeotropic mixture of DFP, methanol, and tri-methyl borate (TMB—C3H9BO3, using natural boron) in 80:4:16 proportion. The B-CTMFD was about 6 times more sensitive than NB-CTMFD under the most heavily shielded condition and, taken together, also offered 2-energy bin neutron spectroscopic enablement, together with 22-5× higher absolute efficiency and relative sensitivity compared with the nonspectroscopic Ludlum (He-3) and NSN3 (methane-nitrogen) based detectors. From an intrinsic efficiency standpoint, the B-CTMFD operating at Pneg = 0.7 MPa state demonstrated ∼103× higher intrinsic efficiency over Ludlum 42-49B and NSN3 detectors, respectively.

ABSTRACT Trimethyl borate (TMB) is an excellent alternative to alter the combustion of conventional fuels due to the combination of boron, stable methyl groups, and oxygen, which can improve the combustion behavior in many ways compared to alcohols and etheric hydrocarbon structures. In this research, the combustion and energetic phenomena trends of trimethyl borate blends was investigated on a droplet scale. The camera systems were used at the combustion characteristics look at how the size of the droplets, the structure of the flame, and the flame temperature changed over time. The additions of 20%, 40%, 60%, and 80% trimethyl borate fuel to gasoline were tested for their ability to burn. As the amount of TMB increased, high variations in droplet deformation and high breakups from the hemispheric geometry occurred. At this point, changes were observed in droplet shape change independent of mixing ratio. TMB droplet had the highest flame temperature of 600 K and the lowest extinction time of ~ 1270 ms. As the gasoline content of the droplets increased, the droplet flame temperature tended to decrease. Also, the shortest ignition delay time was observed for pure TMB and fuel droplets containing 40%, 60% and 80% TMB (~0.714 ms).

ABSTRACT Hydrogen plays a critical role in reducing dependence on fossil fuels and combating climate change as a clean, highly efficient, and renewable energy source. In this study, hydrogen production via methanolysis of sodium borohydride (NaBH4) has been investigated in the presence of boric acid (H3BO3) catalyst. The effect of various parameters on hydrogen generation rate has been reported and the effect of temperature, H3BO3 catalyst concentration, methanol volume and NaBH4 concentration has been studied in the range of 20–50°C, 0.539–2.695 mM, 2–20 mL, and 0.176–0.881 mM, respectively. The kinetic parameters are estimated with the power law model and the reaction order and activation energy are found as 2 and 33.25 kJ·mol−1, respectively. The highest hydrogen generation rate (HGR) is achieved as 628,117 mL·min−1·g cat−1 at 50°C with 1.078 mM H3BO3 and 0.352 M NaBH4 concentrations and 15 mL methanol volume. This study’s notable result is the emphasis on the effect of using a very small amount of boric acid. Because the use of a high amount of boric acid as a catalyst causes steric hindrance in the methanolysis reaction of trimethyl borate, which is the product of the equilibrium reaction between boric acid and excess alcohol in the solution. This situation has been avoided by using a lower amount of boric acid. Thus, it demonstrates that environmentally friendly, efficient, and cost-effective boric acid has great potential in hydrogen production via methanolysis and that its performance can be further improved with more work on the optimization of catalyst concentration.

Abstract Total syntheses of borolithochromes A, D and G, red pigments isolated from fossils of Jurassic putative red alga Solenopora jurassica, have been achieved. The benzo[gh]tetraphene skeletons of the borate ligands in these substances were constructed using Diels–Alder reactions of aryl dienes with naphthoquinone, followed by intramolecular Corey–Chaykovsky reactions. Complexation of these ligands with trimethyl borate generated homocomplexes, which upon sequential O‐demethylation produced borolithochromes A and G. In the route to borolithochrome D, a heterocomplex was prepared by stepwise complexation of the ligands with 2‐(dimethylamino)ethyl dimethyl borate. The strategy devised to accomplish the first total synthesis of borolithochromes A, D and G should be applicable to the preparation of other borolithochromes as well as spiroborates possessing two fused polycyclic aromatic ligands.

Total syntheses of borolithochromes A, D and G, red pigments isolated from fossils of Jurassic putative red alga Solenopora jurassica, have been achieved. The benzo[gh]tetraphene skeletons of the borate ligands in these substances were constructed using Diels-Alder reactions of aryl dienes with naphthoquinone, followed by intramolecular Corey-Chaykovsky reactions. Complexation of these ligands with trimethyl borate generated homocomplexes, which upon sequential O-demethylation produced borolithochromes A and G. In the route to borolithochrome D, a heterocomplex was prepared by stepwise complexation of the ligands with 2-(dimethylamino)ethyl dimethyl borate. The strategy devised to accomplish the first total synthesis of borolithochromes A, D and G should be applicable to the preparation of other borolithochromes as well as spiroborates possessing two fused polycyclic aromatic ligands.

Interface engineering strategy via electron-defect trimethyl borate additive toward 4.7 V ultrahigh-nickel LiNi0.9Co0.05Mn0.05O2 battery

ABSTRACT There is considerable interest in the utilization of fuels derived from boron materials, with their high calorific value, in various applications ranging from propellants to pyrotechnics. Conversely, their impact on the combustion behavior of conventional hydrocarbon fuels remains largely unclear. In this study, ignition, combustion, micro-explosion and simultaneous atomization behaviors of gasoline-based alternative fuels containing metallic (28–35 µm MgB2), nonmetallic (1 µm amorphous boron, 10 µm AlB12 with 86–88% and 95–97% purity) and organo-metallic boron derivatives (triethyl borate (TEB) containing C2H5 groups and trimethyl borate (TMB) containing CH3 groups) were investigated. The experiments were carried out at droplet scale and recorded using a high-speed camera and a thermal camera. The findings revealed a systematic reduction in ignition delay for each gasoline fuel enriched with boron derivatives. 2.5%AlB12/G and pure TMB droplets were the fastest extincting fuel droplets (0.9678 s and 1.245 s, respectively). The highest maximum flame temperature was recorded as 626 K and 610 K for pure TMB and 80%TEB/G, respectively. Droplet diameter regression analyses showed that the diameters of fuel droplets containing predominantly metallic and nonmetallic boron derivatives decreased in accordance with the d 2 -law. This study demonstrated that cost-effective and easily producible amorphous boron and organometallic boron derivatives are promising energy carriers for hydrocarbon fuels.

Preparation of boron-doped diamond-like carbon films via enhanced-PECVD using an additional cathode

Non-π-conjugated [B(OH)3CH3] units as novel deep-ultraviolet (DUV) building blocks are found by the intrinsic modification of the tetrahedron, and the first methyl borate DUV optical crystal, NaB(OH)3CH3, is successfully synthesized.

A copper-catalyzed asymmetric vinylogous conjugate addition of butenolide to 2-ester-substituted chromones is described, and it delivers syn- or anti-chromanone lactones with high stereoselectivities. The enantioselectivity-determining step varied with the use of B(OMe)3 as an additive, resulting in enhanced stereoselectivities, as revealed by density functional theory calculations, which also provided theoretical insight into the origin of the ligand-dependent diastereodivergence.

Evaluation of the boron dose is essential for boron neutron capture therapy (BNCT). Nevertheless, a direct evaluation method for the boron-dose distribution has not yet been established in the clinical BNCT field. To date, even in quality assurance (QA) measurements, the boron dose has been indirectly evaluated from the thermal neutron flux measured using the activation method with gold foil or wire and an assumed boron concentration in the QA procedure. Recently, we successfully conducted optical imaging of the boron-dose distribution using a cooled charge-coupled device (CCD) camera and a boron-added liquid scintillator at the E-3 port facility of the Kyoto University Research Reactor (KUR), which supplies an almost pure thermal neutron beam with very low gamma-ray contamination. However, in a clinical accelerator-based BNCT facility, there is a concern that the boron-dose distribution may not be accurately extracted because the unwanted luminescence intensity, which is irrelevant to the boron dose is expected to increase owing to the contamination of fast neutrons and gamma rays. The purpose of this research was to study the validity of a newly proposed method using a boron-added liquid scintillator and a cooled CCD camera to directly observe the boron-dose distribution in a clinical accelerator-based BNCT field. A liquid scintillator phantom with 10 B was prepared by filling a small quartz glass container with a commercial liquid scintillator and boron-containing material (trimethyl borate); its natural boron concentration was 1wt%. Luminescence images of the boron-neutron capture reaction were obtained in a water tank at several different depths using a CCD camera. The contribution of background luminescence, mainly due to gamma rays, was removed by subtracting the luminescence images obtained using another sole liquid scintillator phantom (natural boron concentration of 0wt%) at each corresponding depth, and a depth profile of the boron dose with several discrete points was obtained. The obtained depth profile was compared with that of calculated boron dose, and those of thermal neutron flux which were experimentally measured or calculated using a Monte Carlo code. The depth profile evaluated from the subtracted images indicated reasonable agreement with the calculated boron-dose profile and thermal neutron flux profiles, except for the shallow region. This discrepancy is thought to be due to the contribution of light reflected from the tank wall. The simulation results also demonstrated that the thermal neutron flux would be severely perturbed by the 10 B-containing phantom if a relatively larger container was used to evaluate a wide range of boron-dose distributions in a single shot. This indicates a trade-off between the luminescence intensity of the 10 B-added phantom and its perturbation effect on the thermal neutron flux. Although a partial discrepancy was observed, the validity of the newly proposed boron-dose evaluation method using liquid-scintillator phantoms with and without 10 B was experimentally confirmed in the neutron field of an accelerator-based clinical BNCT facility. However, this study has some limitations, including the trade-off problem stated above. Therefore, further studies are required to address these limitations.

An experimental study on droplet-scale combustion and atomization behavior in pure ethanol, methanol, and trimethyl borate, and their blends

Controllable preparation of boron nitride microspheres and their epoxy-based thermoconductive composites