Kinetic analysis of formation of boron trioxide from thermal decomposition of boric acid under non-isothermal conditions

Aghili, Siavash; Panjepour, Masoud; Meratian, Mahmood

doi:10.1007/s10973-017-6740-3

Cited by 40 publications

(26 citation statements)

References 75 publications

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“…4 e. This causes decomposition to begin below 200 °C, with a mass loss of 50% at 225 °C. In addition, it is reported that boric acid tends to form B 2 O 3 as it decomposes by heat, and this characteristic is known to affect the decomposition and flame retardant properties 32 . POSS-APBA remains stable up to 280 °C, and was decomposed very slowly as the temperature rises, leaving the half residual mass at 455 °C.…”

Section: Resultsmentioning

confidence: 99%

Insulin smart drug delivery nanoparticles of aminophenylboronic acid–POSS molecule at neutral pH

Kim

Kwon

Cho

et al. 2021

Sci Rep

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Self-regulated “smart” insulin administration system that mimic pancreatic endocrine function would be highly desirable for diabetes management. Here, a glucose-responsive continuous insulin delivery system is developed, where novel polyhedral oligosilsesquioxane (POSS) modified with 3‐aminophenylboronic acid (APBA) were used to encapsulate insulin (insulin entrapment efficiency: 73.2%) to prepare a fast response, high stability, good distribution, and excellent biocompatible system. Due to the strong hydrophobicity of POSS, the POSS moiety is located at the core in aqueous solution and combines with the boronic group of APBA and the diol generated in PEG-insulin to form a nanomicelle structure, that is, nanoparticles naturally. Micelles self‐assembled from these molecules possess glucose‐responsiveness at varying glucose concentrations. The interaction of the PBA and diol containing insulin via boronate ester bond and its interchange with glucose was investigated by FT-IR, 1H NMR and XPS. Furthermore, the successful glucose-triggered release of insulin from the POSS-APBA micelles was investigated at neutral pH. A linear graph was plotted with the measured released insulin vs glucose concentrations, with a linear correlation coefficient (R2) value close to 1. Circular dichroism (CD) spectroscopy analysis was performed to measure insulin activity by comparing secondary structures of insulin, PEG-Insulin, and POSS-APBA@insulin. When confirming intracellular apoptosis signaling, cleaved caspase 3 and caspase 9 were not increased by 640 μg/ml POSS-APBA and POSS-APBA@insulin in HeLa, HDF and HUVE cells. Application in the biomedical field for controlled delivery of insulin appear to be promising.

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Section: Resultsmentioning

confidence: 99%

Insulin smart drug delivery nanoparticles of aminophenylboronic acid–POSS molecule at neutral pH

Kim

Kwon

Cho

et al. 2021

Sci Rep

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“…The first weight loss of ~10% from room temperature to 100°C associated with endothermic signals appearing on the DSC profile at 91°C 69 is connected with the evacuation of solvent and the bound water 70 in the porous structure of the fibers. The second weight loss of ~14% occurs in the range 100‐330°C, associated with some exothermic signals appearing on the DSC profile at 136, 191, and 286°C, can be attributed to the decomposition and dehydration stages of H 3 BO 3 71 . The third weight loss of ~45% in the range 330‐440°C connected with exothermic signals appearing on the DSC profile at 416°C can be due to higher degrees of crosslinking as a result of thermal polycondensation and degradation of PVP to form amorphous carbon 72,73 and decomposition of organic residues 70 .…”

Section: Resultsmentioning

confidence: 98%

“…The second weight loss of ~14% occurs in the range 100-330°C, associated with some exothermic signals appearing on the DSC profile at 136, 191, and 286°C, can be attributed to the decomposition and dehydration stages of H 3 BO 3 . 71 The third weight loss of ~45% in the range 330-440°C connected with exothermic signals appearing on the DSC profile at 416°C can be due to higher degrees of crosslinking as a result of thermal polycondensation and degradation of PVP to form amorphous carbon 72,73 and decomposition of organic residues. 70 The fourth weight loss between 440 and 600°C (~8%) with some exothermic peaks at 446, 461, and 561°C in the DSC curve correlates to dehydroxylation of Hf-OH into HfO 2 .…”

Section: Ftir Analysis Of Precursor Fibers Prepared Under Differentmentioning

confidence: 99%

A different chemical route to prepare hafnium diboride‐based nanofibers: Effect of chemical composition

Ghelich

Abdizadeh

Jahannama³

et al. 2020

Int J Applied Ceramic Tech

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This study reports on the synthesis of hafnium diboride (HfB2)‐based nanofibers via electrospinning of polyhafnoxanesal (PHO)‐based solution followed by pyrolyzing hafnium‐boron containing polyvinylpyrrolidone precursor fibers by a moderate heat treatment at 1500°C under argon atmosphere. The influence of the molar ratios of C/Hf and B/Hf in preceramic polymer method is investigated on the final phase of HfB2‐based nanofibers. Structural, thermal, microstructural, and physical properties of the hafnium‐based fibers are evaluated using Fourier transform infrared spectra (FTIR), thermogravimetry and differential scanning calorimetry (TG/DSC), X‐ray diffractometer (XRD), high‐temperature X‐ray diffraction (HT‐XRD), field‐emission scanning electron microscope/energy‐dispersive spectrometer (FE‐SEM/EDS), and Brunauer‐Emmett‐Teller (BET). The results unveiled that the acidic pH was the optimal condition needed for obtaining the single phase of HfB2 nanofibers. The precursor fibers with the stoichiometric ratio of 1:4:5 of Hf:B:C prepared under the acidic conditions converted into pure HfB2 nanofibers having rough and porous surface after pyrolysis at 1500°C for 2 hour in argon, whereas HfB2‐HfC composite nanofibers with smooth surface were produced in the neutral conditions. The HfB2 nanofibers with a mean diameter of ~100 nm prepared under the acidic conditions showed a higher specific surface area compared to HfB2‐HfC composite nanofibers with a diameter of ~121 nm derived in the neutral conditions.

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“…The mass loss was attributed to each of this reaction steps. Within this new approach different crystalline modifications of boric acid were analysed, however, in this case the crystalline modifications of metaboric acid appear to be insignificant for the reaction [22,23]:…”

Section: Discovery and Mechanismmentioning

confidence: 99%

Boric Acid: A High Potential Candidate for Thermochemical Energy Storage

et al. 2019

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This paper aims to describe the capability of the system boric acid–boron oxide for thermochemical energy storage. As part of the systematic research and in-depth analysis of potential solid/gas reaction systems, performed during the last years, this reaction system appears to be highly promising for the future of worldwide sustainable energy supply. The analysis of the reaction heat, by means of thermogravimetric and macroscopic investigations, not only showed a significantly higher energy density of 2.2 GJ/m3, compared to sensible- and latent energy storages, but the reaction kinetic further demonstrated the reactions’ suitability to store energy from renewable energy and waste heat sources. This paper, therefore, shows a new approach regarding the application of the boric acid–boron oxide reaction system and elaborates on the advantages and challenges for its use as energy storage.

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Kinetic analysis of formation of boron trioxide from thermal decomposition of boric acid under non-isothermal conditions

Cited by 40 publications

References 75 publications

Insulin smart drug delivery nanoparticles of aminophenylboronic acid–POSS molecule at neutral pH

Insulin smart drug delivery nanoparticles of aminophenylboronic acid–POSS molecule at neutral pH

A different chemical route to prepare hafnium diboride‐based nanofibers: Effect of chemical composition

Boric Acid: A High Potential Candidate for Thermochemical Energy Storage

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