Absence Of Boric Acid Research Articles

The Multifaceted Role of Boric Acid in Nickel Electrodeposition and Electroforming

This study involved an investigation of the role of boric acid in nickel electroforming from sulfamate electrolytes, especially in relation to its ability to minimise interfacial pH changes during electrodeposition. Initial speciation calculations indicated that buffering by polyborate species and nickel-borate complexes are most likely responsible for this effect. However, the concentration of nickel-borate complexes was too low even at elevated pH to be a significant electroactive species. Polarisation and electrochemical quartz crystal microbalance measurements indicated that, in the absence of boric acid, electrodeposits typically contained Ni(OH)2, while boric acid additions resulted in pure Ni being deposited with a current efficiency approaching unity. Boric acid additions substantially modified the nickel and hydrogen partial currents, and influenced the overall current efficiency. Studies in nickel-free solutions indicated that boric acid adsorbs on the surface which explains the suppression of H2O reduction observed in the electroforming experiments. Collectively, solution buffering due to polyborate and nickel-borate species and inhibition of H2O reduction by adsorbed boric acid minimised interfacial pH changes and prevented the formation of nickel hydroxide.

Electrodeposition of Pt1-XMx (M=Ni,Co) Alloys for Magnetic Thermometry

Electrodeposited Pt1-xMx (M=Ni,Co) alloys were studied for possible use in a magnetic thermometry application. The effects of boric acid and potential on the deposition process and on magnetic properties of the resulting films were examined. Both alloy series showed a monotonic decrease in platinum content as the potential was stepped to progressively more reducing potentials. While films in the Pt1-xNix series were all face centered cubic (fcc), those in the Pt1-xCox series showed a transition from fcc to hexagonal close packed as the films became more cobalt rich. For the Pt1-xNix system, the presence of B(OH)3 during deposition was accompanied by decreased Coulombic efficiency at more reducing deposition potentials, increased oxygen incorporation, and decreased magnetization relative to films deposited in the absence of boric acid.[1] For the Pt1-xCox system, the presence of B(OH)3 also resulted in lower Coulombic efficiency and in lower magnetizations over an intermediary potential range. In contrast to the Pt1-xNix, the decreased Coulombic efficiency for the Pt1-xCox system was also accompanied by a strong suppression of the deposition process. For both series, the Curie temperature decreased with increasing platinum content, allowing the magnetic thermosensitivity to be optimized for a particular temperature range of interest by appropriate selection of the deposition potential.

Adsorption of Lactose Using Anion Exchange Resin by Adding Boric Acid from Milk Whey

The influence of adding boric acid (BA) on the adsorption behavior of lactose onto an anion exchange resin (IRA402) was investigated. By adding BA, the amount of lactose adsorbed onto IRA402 was increased ca. 20% compared to without adding BA. In the presence of BA, ca. 70% of the adsorbed lactose could desorb from IRA402, while the absorbed lactose hardly desorbed in the absence of BA. Lactose molecules were considered to bind to tertiary amine group on IRA402 by Maillard reaction. The optimum conditions of the dosage of BA and pH were found at the molar ratio of BA to lactose ranging from 1–2, and pH 7–9. The kinetics and equilibrium of lactose adsorption could be explained by the Langmuir adsorption model (best model). In the case of a real whey solution, phosphate strongly affected the adsorption behavior and could be removed as precipitation from the whey over pH 10. Whey proteins had little effect on lactose adsorption, which was ca. 30% less than that in the model system. Moreover, the different kinds of whey proteins and amino acids had little effect on the amount adsorbed. Minerals in the whey may also be considered to be responsible for the decreased adsorption in the whey.

Electrodeposition of Platinum-Transition Metal Alloys for Magnetic Thermometry

The present work seeks to develop materials and structures with temperature-dependent magnetic properties providing optimal sensitivity for near-room temperature thermometry. Studies of the electrodeposition of Pt1-xMx (M=Ni,Co) alloys will be presented. The effects of boric acid and deposition potential on the deposition process and magnetic properties of Pt1-xNix and Pt1-xCox films will be compared. For Pt1-xNix, it was found that the presence of boric acid during deposition was accompanied by decreased Coulombic efficiency at more reducing deposition potentials, increased oxygen incorporation, and decreased magnetization relative to films deposited in the absence of boric acid.[1] Preliminary results for the Pt1-xCox system indicate its behavior is not simply analogous to the Pt1-xNix system.[1] Rus, E. D.; L. Corrêa, E.; Groopman, E.; Williamson, T.; Hijazi, H.; Kasaei, L.; Dennis, C. L.; Moffat, T. P., Magnetic Characterization of Electrodeposited Pt1−xNix Alloy Films: Influence of Deposition Potential and the Presence of Boric Acid, J. Electrochem. Soc. 2022, 169 (9), 10.1149/1945-7111/ac8ad1.

Electrochemical detection of boric acid using gallacetophenonato-(β-diketonato) ruthenium complex in water.

A simple and practical method for boron detection in water is desired in various fields such as seawater desalination, water conservation, and plant production. To develop a method for detecting boron as boric acid in water, we synthesized [Ru(acac)2(H2thap)] (acac = acetylacetonat ion, thap = 2',3',4'-trihydroxyacetophenonate (gallacetophenonate) ion) possessing a cis-diol moiety that interacts with boric acid. A comparison of UV-visible (UV-vis) absorption spectra measured in the presence and absence of boric acid at various pH values revealed that [Ru(acac)2(H2thap)] shows the highest response to boric acid at pH 8.5. Cyclic voltammograms (CVs) and differential pulse voltammograms (DPVs) of [Ru(acac)2(H2thap)] aqueous solution at pH 8.5 with varying boric acid concentrations showed a decrease in the peak current value at 0.032V (vs. Ag|AgClaq.) and an increase in the peak current value at 0.444V with increasing boric acid concentration. On the basis of the relationship between the ratio of current values (at 0.032V and 0.444V) and boric acid concentrations, the binding constant (assuming a 1:1 binding model) for the interaction between [Ru(acac)2(H2thap)] and boric acid was estimated to be 135.1 ± 9.1mol-1 dm3, and the Limit of Detection (LOD) was calculated to be 1.03mg B L-1.

Catalytic oxidation performance and ion-exchange of Ti-MWW zeolite membrane with dual organic template agents and potassium carbonate

In the absence of boric acid, the tubular Ti-MWW zeolite membranes are prepared with dual organic template agents and potassium carbonate by secondary hydrothermal synthesis. 12MR cage and 10 MR of the MWW zeolite topology structure is stabilized by TMAdaOH and HMI organic template agents, K+ cations is a critical mineralization agent for preparing Ti-MWW zeolite membrane with bi-layer Ti-MWW zeolites layer in this work. Besides, ion-exchange could greatly improve the catalytic performance of the Ti-MWW zeolite membrane for phenol hydroxylation with H2O2, influences of ammonium salt, ion-exchange time and temperature on the micro-structure and catalytic performance are investigated. The upper network-like Ti-MWW zeolite layer could be dissolved and removed by ion-exchange with 0.5 M (NH4)2SO4 solution at 60 °C for 24 h, and the “lying” Ti-MWW zeolites layer is kept on the mullite support. On the other hand, ion-exchange could promote the transformation of hexacoordinated extra-framework titanium species to tetracoordinated state in the framework, part of K+ cations of Ti-MWW zeolites are replaced with NH4+ cations. Total flux and phenol conversion of the ion-exchanged Ti-MWW zeolite membrane are 14.89 kg·m−2·h−1 and 36.49 % for phenol hydroxylation by H2O2 at 50 °C.

Boric Acid Detection in Water by Gallacetophenone

The detection of boron down to ppt order in ultrapure water is required to ensure high-quality and stable semiconductor manufacturing. To realize a simple yet sensitive method for the detection of boron (=boric acid), we designed a ruthenium complex possessing a stable ligand with boric acid sensing function. Gallacetophenone (2’,3’,4’-trihydroxyacetophenone) ligand has a β-diketone moiety that can coordinate to a metal and a cis-diol moiety that shows reactivity with boric acid. Comparison of UV-vis absorption spectra measured in the presence and absence of boric acid at various pH revealed that gallacetophenone showed the greatest response to boric acid at pH 8.58. From the spectral changes in the absorbance of gallacetophenone aqueous solution in various concentrations of boric acid at pH 8.58, decreases in the absorbance at the wavelength of 330 nm were observed with increasing boric acid concentration. On the basis of the relationship between the absorption spectra and the boric acid concentration, the binding constant (assuming a 1:1 binding model) for the interaction between gallacetophenone and boric acid was estimated to be 420.7 ± 28.0 mol-1 dm3. The electrochemical detection of boric acid was also conducted.

Electrodeposition of Transition Metal Alloy Films for Magnetic Thermometry

As part of an effort to develop methodology for magnetism-based thermometry, the present work seeks to develop materials and structures with temperature-dependent magnetic properties providing optimal sensitivity near room temperature, leveraging previous work which demonstrated compositional control of alloy films by varying the deposition potential. We will discuss deposition and characterization of these films with an emphasis on factors affecting their temperature-dependent magnetic properties, namely the effects of deposition potential and the presence of boric acid. A series of electrodeposited platinum nickel alloy films was characterized by superconducting quantum interference device vibrating sample magnetometry (SQUID VSM), and it was found that films deposited at more reducing potentials (those with higher nickel content) had predominantly ferromagnetic behavior, while films deposited at more positive potentials showed behavior with ferromagnetic and paramagnetic contributions. Depositions at more reducing potentials in the presence of boric acid proceeded with lower Coulombic efficiency and resulted in films with higher oxygen content and diminished magnetization relative to depositions in the absence of boric acid.

DNA Strand Breaks Induced by Fast and Thermal Neutrons from YAYOI Research Reactor in the Presence and Absence of Boric Acid.

It is well known that neutrons have more damaging effects, with high relative biological effectiveness or a radiation weighting factor depending on neutron energy, compared to low-LET ionizing radiations. In the current work, we evaluated the contribution of the indirect effect induced by radicals for the purpose of studying the mechanisms of fast neutron effects or mechanisms of boron neutron capture therapy (BNCT) using relatively lower energy neutrons. Plasmid pBR322 DNA with a supercoiled structure was irradiated with fast neutrons (1-10 MeV) in the reactor core of the YAYOI research reactor at the University of Tokyo, and with thermalized neutrons passing through a phantom made of acrylic resin to simulate a human body. The single- and double-strand breaks (SSBs and DSBs) of the plasmid were evaluated from the numbers of its open circular and linear forms, respectively, detected using agarose gel electrophoresis. The number of supercoiled forms decreased exponentially with the absorbed dose of fast neutrons. The decrease was inhibited by dimethyl sulfoxide (DMSO) in a concentration-dependent manner. The contributions of the indirect effect to DNA strand breaks by fast neutrons and thermalized neutrons were calculated to be 50-65% which, while lower than the value for X rays, still accounts for the majority of the DNA strand breaks. In the case of thermalized neutrons, SSB and DSB yields were increased by the addition of boric acid. Moreover, an increased 10B isotope concentration was found to increase the DSB/SSB ratio.

Investigation of phase stability of poly(1-oxotrimethylene)-dissolved aqueous solutions containing ZnCl2/CaCl2/LiCl: Influence of boric acid introduction and aging time

Poly(1-oxotrimethylene) (POTM) was dissolved in aqueous solutions containing ZnCl2, CaCl2, and LiCl, and the effects of boric acid introduction on the phase stability of the POTM solutions over various aging times were investigated. In the absence of boric acid, aging at 70°C for 8 h notably reduced the loss tangent (tanδ) for the 7.0 wt.% POTM solutions. Addition of boric acid into unaged solutions had little effect on tanδ over the frequency range measured, regardless of its content, whereas addition of 0.3-1.0 wt.% of boric acid into aged solutions increased tanδ. The dynamic viscosity of the POTM solutions with 1.0 wt.% boric acid was affected little by aging time. Conversely, the POTM solutions without boric acid exhibited increased dynamic viscosity in the low-frequency range with aging time. In addition, the slope of the solutions in the Cole-Cole plot decreased with increasing aging time in the absence of boric acid, whereas aging time had little effect in the presence of 1.0 wt.% boric acid. For dilute POTM solutions (i.e., 0.5 g/dL), the reduced viscosity decreased with increasing aging time in the absence of boric acid, while it was affected little in solutions with the addition of 1.0 wt.% boric acid. In the UV-Vis spectra, the aging-time-dependent increase of the absorbance peak at 390 nm was associated with the generation of a chromophoric complex in the POTM solutions. Conversely, the disappearance of the peak due to the addition of boric acid indicated suppression of complex formation.

Dispersion of Vesicles Composed of Industrially Produced Alkyl (Oligo) Glucoside Using Diol-Boron Complexation.

Alkyl (oligo)glucosides (AOG) are known to be environmentally compatible amphiphiles whose commercial applicability should be broadened. The present paper describes the preparation of molecular assemblies of industrially produced AOG, which is a mixture composed of different length of alkyl chains (C9-C12) with oligoglucoside moiety with a few (1-3) of glucose units. It was also described that regulation of the dispersibility of the molecular assemblies prepared by diol-boron complexation between the sugar moiety on AOG and boric acid in a dispersion medium. The molecular assembly of AOG was successfully formed by mixing AOG and cholesterols (CH). When using a suitable amount of CH (20-40 mol% with respect to AOG), the molecular assembly formed a vesicle structure. The dispersion ability of the resulting vesicle was dependent on both the boric acid concentration and pH of the dispersion medium. The light-scattering and ζ-potential measurements revealed that high concentrations (≥10 mM) of boric acid improved dispersibility the vesicles. In contrast, the vesicle agglomerated at low concentrations of boric acid (1-7.5 mM). In the absence of boric acid in dispersion medium, the vesicles were completely agglomerated. The optimum pH range for vesicle dispersion was found to be from neutral to basic (7.4-10.1). The (11)B NMR study revealed that borate ester formation occurred between boric acid and the diol of the sugar moiety on AOG vesicle. The present data suggest that borate ester formation that occurred on the surface of the vesicle provided negative charge to the vesicles, contributing to their dispersion via repulsive forces.

Characteristics of β-glucosidase production by Paecilomyces variotii and its potential application in bioassay system for boric acid determination

This study reports the potential application of Paecilomyces variotii immobilized in calcium alginate beads as a sensing element in the analysis of boric acid. In the presence of boric acid, β-glucosidase production of P. variotii was inhibited and the changes of β-glucosidase concentration were correlated to the concentrations of boric acid. The optimum conditions of β-glucosidase production were observed when 6% (w/v) mycelia of P. variotii was immobilized in 2% (w/v) sodium alginate with 0.25 M calcium chloride, at initial pH 7 and temperature 45°C. The response time of less than 3 h exhibited by P. variotii towards boric acid was observed. A linear response range of boric acid concentration was obtained within the range of 0.05 to 0.215% (w/v), with a detection limit of 0.037% (w/v). The immobilized cell beads were considered reproducible with the relative standard deviation (RSD) of 4.96 and 4.81% in the presence (0.2% w/v) and absence of boric acid, respectively. From the results, P. variotii could be beneficially useful towards developing an alternative approach for boric acid analysis.

Co–Ni alloy electrodeposition under different conditions of pH, current and composition

Linear sweep voltammetry and cathodic polarization experiments were conducted to investigate the effects of electrolyte composition and current/overpotential on Co–Ni alloy co-deposition in sulphate solutions and its anomalous behavior whereby Co is preferentially deposited over Ni. Ni deposition was shown to be inhibited in the presence of CoSO4 in solution, whereas the rate of Co deposition was not accelerated and, in fact, completely unaffected by the presence of NiSO4. The extent of anomalous behavior was found to be affected strongly by the CoSO4 concentration, but was less pronounced when Co(II) reduction became mass transfer-controlled or the NiSO4 concentration exceeded the CoSO4 concentration by at least one order of magnitude. Analysis of the linear scans and measurement of the deposition current efficiencies indicated that the onset of reactions occurred in the following order with increasing cathodic overpotential: H+ reduction, Ni(II) reduction, Co(II) reduction and H2O reduction. Boric acid was found to have little effect on alloy composition whenever deposition occurred to any significant extent. On the other hand, the presence of boric acid was required to attain acceptably high current efficiencies over a wide range of current densities. Moreover, effective Co–Ni deposition was not possible in the absence of boric acid.

Structure and electrokinetic study of nickel electrodeposition

Electrodeposited layers of nickel show different growth characteristics depending on the composition of the electrolyte, namely the type of the anion, the presence or the absence of boric acid and the pH. These process parameters are examined in the present work in order to elucidate their influence upon the growth texture and the related surface morphology of the electrodeposits. The relationship between process and structure is investigated by studying the transient electrochemical behavior during deposition, in order to discriminate between different interface conditions corresponding to different growth modes. The observed preferred orientations can be in this way linked to different reactive species, which are assumed to be present at the surface, and to their stability. The correlation between kinetics and structure in nickel electrodeposition reported in the present work and the similar correlation found in cobalt electrodeposition suggest a rationalization of the growth modes of ECD inert metals, based on the correspondence between the transient Tafel parameter and the growth texture observed in defined conditions.

Influence of Boric Acid in the Extraction of Uranium (VI), Plutonium (IV) and Europium (III) from Fast Reactor Fuel Dissolver Solution

Addition of boric acid to dissolver solution has been proposed for minimizing the criticality concern associated with reprocessing of fast reactor fuel. Extraction of uranium (VI) and plutonium (IV) from the resultant nitric acid – boric acid medium by a solution of tri-n-butyl phosphate (TBP) in n-dodecane (n-DD) has been studied at 298 K. The distribution ratios of uranium (VI) and plutonium (IV) were found to be comparable with those obtained in the absence of boric acid. Extraction of europium (III) from nitric acid – boric acid by a solution of 1.2 M TBP–0.2 M n-octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in n-DD was also studied. The solubility limit of boric acid as a function of nitric acid concentration was determined and it was found to decrease from 61.5 g/L in 0.1 M HNO3 to 32.4 g/L in 4 M HNO3 at 303 K. Extraction of boric acid in 1.1 M TBP/n-DD and in a solution of 1.2 M TBP–0.2 M CMPO in n-DD was studied and it was found to increase with increase in the concentration of boric acid above ~0.2 M. The study indicated that the interference of boric acid during the extraction of uranium (VI) plutonium (IV) by PUREX solvent and Eu(III) by TRUEX solvent was negligible and the added boric acid could be quantitatively retained in aqueous phase provided the boric acid concentration was fixed below 6 g/L (~0.1 M) in the feed solution.

Poly(borosiloxanes) as precursors for carbon fiber ceramic matrix composites

Ceramic matrix composites (CMCs), constituted of a silicon boron oxycarbide (SiBCO) matrix and unidirectional carbon fiber rods as a reinforcement phase, were prepared by pyrolysis of carbon fiber rods wrapped in polysiloxane (PS) or poly(borosiloxane) (PBS) matrices. The preparation of the polymeric precursors involved hydrolysis/condensation reactions of alkoxysilanes in the presence and absence of boric acid, with B/Si atomic ratios of 0.2 and 0.5. Infrared spectra of PBS showed evidence of Si-O-B bonds at 880 cm-1, due to the incorporation of the crosslinker trigonal units of BO3 in the polymeric network. X ray diffraction analyses exhibited an amorphous character of the resulting polymer-derived ceramics obtained by pyrolysis up to 1000 °C under inert atmosphere. The C/SiBCO composites showed better thermal stability than the C/SiOC materials. In addition, good adhesion between the carbon fiber and the ceramic phase was observed by SEM microscopy

Viabilidade do pólen e desenvolvimento do tubo polínico em macieira (Malus spp.)

No presente trabalho, estudaram-se características associadas à germinação in vitro e ao desenvolvimento in vivo do tubo polínico em seis variedades-copa e de porta-enxertos de macieira como subsídios para o estabelecimento de programas de melhoramento genético. Utilizou-se de pólen de seis cultivares de macieira inoculado em meio de cultura com ágar (10 g.L-1) em água destilada, combinados com concentrações de sacarose (0; 10; 20; 30; 40 e 50%) e ácido bórico (0 e 40 mg.L-1). Para o estudo do desenvolvimento do tubo polínico, realizou-se coleta das flores em quatro períodos (6; 12; 24 e 48 horas após as polinizações) em M9 x Marubakaido e a autofecundação em M9, sendo os tubos polínicos analisados em coloração de azul de anilina acidificada/carmim acético e em fluorescência. A sacarose, em concentrações entre 15% a 25%, pode ser empregada com sucesso para a germinação in vitro de grãos de pólen da macieira. O ácido bórico não teve efeito positivo para esta característica. Na ausência do ácido bórico e na presença de 15% de sacarose, observaram-se os maiores percentuais de germinação: Fuji (51,1%), Imperatriz (31,7%), M.9 (20,8%), Catarina (19,2%), Gala (13,7%) e Marubakaido (6,1%). Quanto ao desenvolvimento do tubo polínico, com 12 horas da polinização, iniciou-se a germinação no pólen, no estigma, no cruzamento M.9 x Marubakaido, e após 24 horas da polinização observou-se 83% de germinação. As técnicas de coloração com azul de anilina acidificada com carmim acético e de visualização em fluorescência foram eficientes na visualização e coloração dos grãos de pólen e do desenvolvimento dos tubos polínicos.

A study on effect of hydrogen reduction reaction on the initial stage of Ni electrodeposition using EQCM

Electrodeposition of Ni from acidic sulfate solution with/without the addition of boric acid was studied by electrochemical quartz crystal microbalance (EQCM) to further investigate the initial stage of Ni deposition. EQCM analysis showed that nickel hydroxide was formed due to the pH increase near the electrode caused by hydrogen evolution in the absence of boric acid. In the presence of boric acid, nickel hydride was formed. EQCM was found to be a useful in-situ tool for investigating the effects of the evolution and absorption of hydrogen on metal deposition and separating the charge used for Ni deposition and for hydrogen reduction.

Effect of Mg2+, Li+, Na+ and K+ on the electrocrystallization of nickel from aqueous sulfate solutions containing boric acid

The effects of metal ions such as Mg2+, Li+, Na+ and K+ on the cathodic current efficiency, deposit morphology, crystallographic orientation and polarization behaviour during nickel deposition on stainless steel from aqueous sulfate solutions containing boric acid were investigated. There was virtually no change in current efficiency in presence of these metal ions, but changes were observed in the deposit morphologies and crystal orientations even though all the deposits looked bright, smooth and coherent. Changes were also observed in the polarization behaviour during nickel electrocrystallization in presence and absence of boric acid. An attempt has been made to correlate the effect of these metal ions on various parameters studied.

Oxygen Incorporation during the Electrodeposition of Ni, Fe, and Ni‐Fe Alloys

This study sought to quantify the oxygen content of electrodeposited Ni, Fe, and Ni‐Fe alloys and to identify mechanisms by which the oxygen is incorporated in the deposits. In the absence of boric acid in the bath, the oxygen content of electrodeposited Ni increases with increasing applied current density. This behavior corresponds to a significant increase in the pH of the solution adjacent to the cathode, which results in the precipitation of on the cathode and occlusion of this material in the growing deposit. The incorporation of oxygen during Ni‐Fe electrodeposition is similar, except that an increase in the concentration in the bath reduces the oxygen content. This behavior results from buffering provided by that accompanies the in this system. When boric acid is present in the bath, oxygen incorporation is low in all three electrodeposition systems. This observation is consistent with buffering of the cathode pH resulting from boric acid’s ability to complex with , which generates as a by‐product. The oxygen that is incorporated may be attributed to hydroxide ion that fails to leave the surface following its participation in the electroreduction process. In Ni‐Fe electrodeposition, oxygen incorporation by particle codeposition is shown to play an insignificant role.