Hydrolytic Stability and Photostability of Boron Complexes of Dibenzoylmethane with Various Substituents at the Boron Atom

Porous boron nitride is gaining significant attention for applications in molecular separations, photocatalysis, and drug delivery. All these areas call for a high degree of stability (or a controlled stability) over a range of chemical environments, and particularly under humid conditions. The hydrolytic stability of the various forms of boron nitride, including porous boron nitride, has been sparingly addressed in the literature. Here, we map the physical-chemical properties of the material to its hydrolytic stability for a range of conditions. Using analytical, imaging and spectroscopic techniques, we identify the links between the hydrolytic instability of porous boron nitride and its limited crystallinity, high porosity as well as the presence of oxygen atoms. To address this instability issue, we demonstrate that subjecting the material to a thermal treatment leads to the formation of crystalline domains of h-BN exhibiting a hydrophobic character. The heat-treated sample exhibits enhanced hydrolytic stability, while maintaining a high porosity. This work provides an effective and simple approach to producing stable porous boron nitride structures, and will progress the implementation of the material in applications involving interfacial phenomena.<br>

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Method of test for hydrolytic stability of electrical insulating materials

10.3403/01257742u ◽

2015 ◽

Keyword(s):

Hydrolytic Stability ◽

Insulating Materials

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Diethylphosphoryl-OxymaB (DEPO-B) as a Solid Coupling Reagent for Amide Bond Formation

Letters in Organic Chemistry ◽

10.2174/1570178615666180612074420 ◽

2018 ◽

Vol 16 (1) ◽

pp. 30-33

Author(s):

Ashish Kumar ◽

Yahya E. Jad ◽

Ayman El-Faham ◽

Beatriz G. de la Torre ◽

Fernando Albericio

Keyword(s):

Bond Formation ◽

Hydrolytic Stability ◽

Solid Material ◽

Amide Bond ◽

Amide Bond Formation ◽

Coupling Reagent

A new phosphonium based coupling reagent DEPO-B has been synthesized from 5- (hydroxyimino)-1,3-dimethylpyrimidine-2,4,6 (1H,3H,5H)-trione (Oxyma B) and diethyl chlorophosphate in presence of base. It is a solid material and the hydrolytic stability and solubility was evaluated for confirming its capability for usage in automated peptide synthesizer.

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Building a Picture of Heteroborane Isomerisation: Synthesis and Characterisation of the 10-(Dialkyl- sulfane)-7,8-diphenyl-7,8-dicarba-nido-undecaboranes 7,8-Ph2-10-L-7,8-nido-C2B9H10 (L = SMe2, SMeEt, SEt2) and of Intermediate and Isomerised Products Arising from Metallation of the First of These

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19991013 ◽

1999 ◽

Vol 64 (6) ◽

pp. 1013-1027 ◽

Cited By ~ 21

Author(s):

Shirley Dunn ◽

Rhona M. Garrioch ◽

Georgina M. Rosair ◽

Lorraine Smith ◽

Alan J. Welch

Keyword(s):

Boron Atom ◽

Experimental Information ◽

Crystallographic Study

Three new, substituted, nido carboranes, 7,8-Ph2-10-(SMe2)-7,8-nido-C2B9H10 (1a), 7,8-Ph2-10- (SMeEt)-7,8-nido-C2B9H10 (1b) and 7,8-Ph2-10-(SEt2)-7,8-nido-C2B9H10 (1c) have been synthesised and characterised, including a crystallographic study of the first. Deprotonation of 1a followed by treatment with (MeCN)2(CO)2MoBr(η-C3H5) at 0 °C affords the non-icosahedral 1,2-Ph2-4-(SMe2)-5-(η-C3H5)-5,5-(CO)2-5,1,2-closo-MoC2B9H8 (2a), which on subsequent warming transforms into icosahedral 2,8-Ph2-5-(SMe2)-1-(η-C3H5)-1,1-(CO)2-1,2,8-closo- MoC2B9H8 (3a). It is argued that under the conditions of these rearrangements the B-S bond is likely to remain intact, and consequently that the identity of the SMe2-labelled boron atom in 3a affords useful experimental information on the course of the isomerisation.

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Modification of Wood with Monoethanolamino-borate by The Data of X-Ray Photoelectron Spectroscopy

MATEC Web of Conferences ◽

10.1051/matecconf/201819604005 ◽

2018 ◽

Vol 196 ◽

pp. 04005

Author(s):

Irina Stepina ◽

Irina Kotlyarova

Keyword(s):

Particle Size ◽

Photoelectron Spectroscopy ◽

Model Compound ◽

Hydrolytic Stability ◽

Photoelectron Spectra ◽

Wood Cellulose ◽

Rapid Loss ◽

X Ray ◽

Wood Protection ◽

Cellulose Materials

The difficulty of wood protection from biocorrosion and fire is due to the fact that modifiers in use are washed out from the surface of the substrate under the influence of environmental factors. This results in a rapid loss of the protective effect and other practically important wood characteristics caused by the modification. To solve this problem is the aim of our work. Here, monoethanolaminoborate is used as a modifier, where electron-donating nitrogen atom provides a coordination number equal to four to a boron atom, which determines the hydrolytic stability of the compounds formed. Alpha-cellulose ground mechanically to a particle size of 1 mm at most was used as a model compound for the modification. X-ray photoelectron spectra were recorded on the XSAM-800 spectrometer (Kratos, UK). Prolonged extraction of the modified samples preceded the registration of the photoelectron spectra to exclude the fixation of the modifier molecules unreacted with cellulose. As a result of the experiment, boron and nitrogen atoms were found in the modified substrate, which indicated the hydrolytic stability of the bonds formed between the modifier molecules and the substrate. Therefore monoethanolaminoborate can be considered as a non-extractable modifier for wood-cellulose materials.

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Synthetic glass and jute fabric reinforced soy-based biocomposites: Development and characterization

Polymers and Polymer Composites ◽

10.1177/09673911211020609 ◽

2021 ◽

pp. 096739112110206

Author(s):

Ajaya Kumar Behera ◽

Chirasmayee Mohanty ◽

Nigamananda Das

Keyword(s):

Hybrid Composites ◽

Hydrolytic Stability ◽

Glass Fabric ◽

Soil Burial ◽

Jute Fabric ◽

Reinforced Composite ◽

Original Weight ◽

Fabric Composites ◽

Biodegradation Study ◽

Burial Condition

In this work, both glass fabric and jute fabric reinforced nanoclay modified soy matrix-based composites were developed and characterized. Glass fabric (60 wt.%) reinforced composite showed maximum tensile strength of 70.2 MPa and thermal stability up to 202°C, which are 82.8% and 12.2% higher than those observed with corresponding jute composite. Water absorption and contact angle values of glass-soy specimens were tested, and found composites are water stable. Biodegradation study of composites under soil burial condition revealed that glass-soy composite with 40 wt.% glass fabric lost maximum 32.6% of its original weight after 60 days of degradation. The developed glass fabric-soy hybrid composites with reasonable mechanical, thermal, and hydrolytic stability can be used in different sectors as an alternative to the nondegradable thermoplastic reinforced glass fabric composites.

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The Use of MgO Obtained from Serpentinite in the Synthesis of a Magnesium Potassium Phosphate Matrix for Radioactive Waste Immobilization

Applied Sciences ◽

10.3390/app11010220 ◽

2020 ◽

Vol 11 (1) ◽

pp. 220

Author(s):

Svetlana A. Kulikova ◽

Sergey E. Vinokurov ◽

Ruslan K. Khamizov ◽

Natal’ya S. Vlasovskikh ◽

Kseniya Y. Belova ◽

...

Keyword(s):

Radioactive Waste ◽

Hydrolytic Stability ◽

Potassium Phosphate ◽

Aggregate Size ◽

Particle Morphology ◽

Average Crystallite Size ◽

Cost Effective ◽

Binding Agent ◽

Ultrasonic Dispersion ◽

Radioactive Waste Immobilization

Magnesium oxide is a necessary binding agent for the synthesis of a magnesium potassium phosphate (MPP) matrix based on MgKPO4 × 6H2O, which is promising for the solidification of radioactive waste (RW) on an industrial scale. The performed research is devoted to finding a cost-effective approach to the synthesis of MPP matrix by using MgO with an optimal ratio of the quality of the binding agent and the cost of its production. A method for obtaining MgO from the widely available natural mineral serpentinite was proposed. The phase composition, particle morphology, and granulometric composition of MgO were studied. It was found that the obtained MgO sample, in addition to the target periclase phase, also contains impurities of brucite and hydromagnesite; however, after calcining at 1300 °C for 3 h, MgO transforms into a monophase state with a periclase structure with an average crystallite size of 62 nm. The aggregate size of the calcined MgO powder in an aqueous medium was about 55 μm (about 30 μm after ultrasonic dispersion), and the specific surface area was 5.4 m2/g. This powder was used to prepare samples of the MPP matrix, the compressive strength of which was about 6 MPa. The high hydrolytic stability of the MPP matrix was shown: the differential leaching rate of magnesium, potassium, and phosphorus from the sample on the 91st day of its contact with water does not exceed 1.6 × 10−5, 4.7 × 10−4 и 8.9 × 10−5 g/(cm2·day), respectively. Thus, it was confirmed that the obtained MPP matrix possesses the necessary quality indicators for RW immobilization.

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