Free energy, configurational and nonextensivity of Tsallis entropy with the size and temperature in colloidal silver nanoparticles in [EMim][PF6] ionic liquid

Kiani, S ; Sharif University of Technology | 2018

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  1. Type of Document: Article
  2. DOI: 10.1016/j.molliq.2017.11.139
  3. Publisher: Elsevier B.V , 2018
  4. Abstract:
  5. Molecular dynamic simulation was performed to calculate the configurational entropy and the free energy for colloidal silver nanoparticles (Ag NPs) in 1-Ethyl-3-methylimidazolium Hexafluorophosphate [EMim][PF6] ionic liquid (IL). Furthermore, the density functional theory (DFT) was used to get the potential interaction between the metal surface and ion in IL. The effect of size and temperature on the configurational entropy and the free energy of colloidal Ag NPs were investigated. Then, it was compared with the gas phase. The Tsallis nonextensivity of entropy was investigated for different sizes of colloidal Ag NPs and it was shown that sub-extensivity of entropy occurs for colloidal Ag NPs. In small sizes of colloidal Ag NPs and at low temperature, Tsallis nonextensivity of entropy is important. The pattern of configurational entropy for Ag NPs in terms of size in gas phase is completely different with colloidal Ag NPs in [EMim][PF6] IL solvent. A non-monotonic behavior for the configurational entropy of colloidal Ag NPs in terms of size was observed. The free energy value for Ag NPs in IL increased in proportion with their sizes however, the free energy of Ag NPs in gas phase decreased as Ag NPs size increased. The results regarding the heat capacity of pure IL and the entropy of silver in bulk structure were in line with the available experimental data. © 2017 Elsevier B.V
  6. Keywords:
  7. Configurational entropy ; DFT and MD simulation ; Free energy ; Silver colloidal nano particle ; Tsallis nonextensive of entropy ; Density functional theory ; Entropy ; Gases ; Ionic liquids ; Metal nanoparticles ; Molecular dynamics ; Nanoparticles ; Specific heat ; Temperature ; Colloidal silver nanoparticle ; Different sizes ; Hexafluorophosphates ; Low temperatures ; MD simulation ; Monotonic behavior ; Tsallis entropies ; Silver
  8. Source: Journal of Molecular Liquids ; Volume 249 , 2018 , Pages 1012-1019 ; 01677322 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/pii/S0167732217331884