Experimental study on the energetics of two indole derivatives

Amaral, Luı́sa M.P.F.; Carvalho, Tânia M.T.; Cabral, Joana I.T.A.; Silva, Manuel A.V. Ribeiro da

doi:10.1007/s10973-013-3332-8

Cited by 11 publications

(3 citation statements)

References 29 publications

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“…The Arrhenius equation was used to investigate the kinetics of oxomemazine first thermal degradation phase. The kinetic parameters were calculated using the Arrhenius equation [16][17][18] , which was applied to solid-state processes. Using the value of conversion fraction (α), (dα/dt) is referred to the rate of the reaction, and f(α) = is defining the function of conversion, then the plot of ln [(dα/dt)/f(α) ] vs 1/T is generated, Fig.…”

Section: Arrhenius Methodsmentioning

confidence: 99%

“…These data may be used to provide insight into how long and in what condition a storage unit has been in use 14 . In this study, non-isothermal approaches such as the arrhenius equation [16][17][18] , Horowitz-Metzger 19 , Coats-Redfern 20 , and Flynn-Wall-Ozawa 21 methods were used to extract kinetic parameters like activation energy and frequency factor of oxomemazine from TG/DTG data.…”

Section: Kinetic Modelsmentioning

confidence: 99%

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Kinetics and Thermal Decomposition Studies of Oxomemazine by Isoconversional Protocols

2022

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Thermogravimetry was used to investigate the thermal decomposition of oxomemazine. Oxomemazine has three distinct degradation processes during non-isothermal decomposition. The Arrhenius equation, Coats-Redfern (CR), Horowitz-Metzger (HM), and Flynn-Wall-Ozawa (F-W-O) equations were used in this research to perform kinetic analysis of the first decomposition stage. Oxomemazine thermal stability is very important when it comes to how it can be stored, quality control, and how long it can be used. Using thermal analysis, scientists have been able to learn more about how drug compounds are stable at different temperatures, as well as how fast they break down. Kinetic studies have emerged as a critical component of thermal analysis, with the primary goal of determining the kinetic model of thermal breakdown and calculating the Arrhenius equation parameters. The activation energy of the Arrhenius and Berthelot–Hood temperature functions was determined. The effect of different heating rates (5- 20 oC/min) on thermogravimetric analysis (TG), Differential Thermal Analysis (DTA) is demonstrated.

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Section: Arrhenius Methodsmentioning

confidence: 99%

Section: Kinetic Modelsmentioning

confidence: 99%

Kinetics and Thermal Decomposition Studies of Oxomemazine by Isoconversional Protocols

2022

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“…Due to the area effect, the volume effect, and the quantum size effect, nanoparticles can swiftly permeate the friction area to prevent direct contact between the surfaces of the friction pair. ,, On a damaged friction surface, nanoparticles with higher surface energies are more likely to precipitate or form a protective coating. Owing to the high demand for lubricating oil additives in the distinctive working environment of marine diesel engines, TiO 2 nanoparticles have been intensively studied as a type of low-cost, nontoxic, and high-performing nano-lubricating additive . Wu et al examined the effects of nano-additives such as CuO, TiO 2 , and diamond on the antifriction properties of the base oil and found that the base oil containing nano-TiO 2 had the highest viscosity and the lowest friction coefficient .…”

Section: Introductionmentioning

confidence: 99%

Tribological Properties of TiO₂@CTAB Core–Shell Nanopowders as Lubricating Additives

Wei

Dai

Cui

et al. 2023

ACS Appl. Nano Mater.

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In this experimental investigation, a core–shell-structured nano-lubricating additive was synthesized utilizing the dielectric barrier discharge plasma (DBDP)-assisted ball grinding technique for a duration of 5 h. The microstructural analysis of the nano-TiO2 powder was performed employing advanced methods such as X-ray diffraction (XRD) and thermogravimetry–differential scanning calorimetry (TG-DSC). The initial particle size of TiO2 was refined from 1 μm to a range of 150–200 nm, resulting in a remarkable increase in lattice distortion rate by 88.2% and an oil affinity enhancement of 200%. Through the introduction of CTAB’s oil-compatible group onto the surface of nano-TiO2 particles, a modified layer with a thickness of 21 nm possessing superior thermal stability and an activation energy (E a) of 600 kJ/mol was successfully produced. Molecular dynamics simulations were conducted to elucidate the mechanism underlying the surface modification of nano-TiO2 powder facilitated by DBDP-assisted ball grinding, thereby revealing the pivotal role of electrostatic forces in the organic modification of the TiO2 surface. It was found that electrostatic forces dominantly govern the cetyl trimethyl ammonium bromide (CTAB)–TiO2 composite interface model, contributing to 70% of the total energy with a maximum energy proportion of −187.84 kcal/mol. To evaluate the lubrication performance of the composite oil samples under boundary lubrication conditions, comprehensive assessments were carried out using the four-ball method and reciprocating friction experiments. The results demonstrated noteworthy enhancements in viscosity index, dynamic viscosity, and oil film thickness within the composite oil samples. Particularly, the composite oil containing 0.5 wt % TiO2@CTAB exhibited outstanding extreme pressure resistance, manifesting a significant reduction of 41.7% in the average friction coefficient, a considerable increase of 25.8% in wear spot diameter, and a substantial elevation of 66.9% in maximum nonseizure load. Compared to the base oil, the incorporation of 0.5 wt % TiO2@CTAB led to a notable increment of 34.7% in oil film thickness, 6.7% in dynamic viscosity, and 9% in viscosity index. In the tribological experiment simulating marine diesel engines, the friction coefficient witnessed a remarkable reduction by 65.8%, accompanied by a substantial decrease of 54.1% in wear rate. This noteworthy improvement in boundary lubrication conditions of the friction pair effectively mitigated friction and wear. For comprehensive characterization of the wear marks, energy-dispersive spectrometry (EDS) and X-ray photoelectron spectroscopy (XPS) techniques were employed to analyze the physical structure and chemical composition. The implementation of TiO2@CTAB nano-lubricating additives resulted in nanobearing and deposition effects, leading to a reduction in contact area and surface roughness, thereby facilitating the restoration of the friction pairs. These findings possess significant implications for extending the service life of die...

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Thermal behavior study and decomposition kinetics of amisulpride under non-isothermal and isothermal conditions

Salama

Mohammad

Fattah

2015

J Therm Anal Calorim

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Experimental study on the energetics of two indole derivatives

Cited by 11 publications

References 29 publications

Kinetics and Thermal Decomposition Studies of Oxomemazine by Isoconversional Protocols

Kinetics and Thermal Decomposition Studies of Oxomemazine by Isoconversional Protocols

Tribological Properties of TiO₂@CTAB Core–Shell Nanopowders as Lubricating Additives

Thermal behavior study and decomposition kinetics of amisulpride under non-isothermal and isothermal conditions

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Experimental study on the energetics of two indole derivatives

Cited by 11 publications

References 29 publications

Kinetics and Thermal Decomposition Studies of Oxomemazine by Isoconversional Protocols

Kinetics and Thermal Decomposition Studies of Oxomemazine by Isoconversional Protocols

Tribological Properties of TiO2@CTAB Core–Shell Nanopowders as Lubricating Additives

Thermal behavior study and decomposition kinetics of amisulpride under non-isothermal and isothermal conditions

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Product

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Tribological Properties of TiO₂@CTAB Core–Shell Nanopowders as Lubricating Additives