Determination of the critical micelle concentration and thermodynamic parameters of phenylcarbamic acid derivatives using a fluorescence method
| Autor: | Fils Andriamainty, Róbert Šandrik, Eva Salanci, Daniel Pecher, Ivan Malík |
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| Rok vydání: | 2021 |
| Předmět: |
Range (particle radiation)
General Chemical Engineering Enthalpy Thermodynamics 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Biochemistry Fluorescence Industrial and Manufacturing Engineering 0104 chemical sciences Gibbs free energy symbols.namesake Entropy (classical thermodynamics) chemistry.chemical_compound chemistry Critical micelle concentration Materials Chemistry symbols Pyrene Phenylcarbamic acid 0210 nano-technology |
| Zdroj: | Chemical Papers. 75:3081-3090 |
| ISSN: | 1336-9075 2585-7290 |
| Popis: | Critical micelle concentration (CMC) values of 1-[3-(2-alkoxyphenylcarbamoyloxy)-2-hydroxypropyl]-4-(4-fluorophenyl)piperazin-1-ium-chlorides (alkoxy = methoxy to propoxy; 6a–c) were determined by a fluorescence method using pyrene as a probe over a temperature interval T = 293.15–313.15 K. The dependence of CMC on T turned out forming the U-shape. The curve was drawn by fitting of observed values using a second-degree polynomial function and so-called power-law equation, minimum of the curve was observed at T = 298.15 K. Thermodynamic parameters of micellization, i.e., molar Gibbs energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°), respectively, were calculated according to a phase separation model. Following the observations, the enthalpy (ΔH°) and entropy contributions (−TΔS°) to the molar Gibbs energy (ΔG°) were calculated. It was found that contribution of enthalpy increased with the increase in temperature, and entropy contribution decreased within chosen range of the temperature. Finally, the enthalpy–entropy compensation and the compensation temperature (Tc) were determined. |
| Databáze: | OpenAIRE |
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