Determinação de propriedades termodinâmicas de líquidos iônicos em condições de alta pressão e alta temperatura

• Autor(a) principal: Medeiros, Lucas Henrique Gomes de
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/65066
• topic: Líquidos iônicos; Densidade; Modelagem termodinâmica; Forças intermoleculares

Ionic liquids (ILs) have gained special attention in the last decades because of their low environmental impact when compared to organic solvents used in chemical processes. In this work, high pressure and high temperature (HPHT) volumetric properties (density) determination for the following ionic liquids triethylsulfonium bis(trifluoromethylsulfonyl) imide [(C2)3S][NTf2], 2,3-dimethyl-1-propylimidazolium bis(trifluoromethylsulfonyl) imide [C3C1C1Im][NTf2], 1-methyl-1-propylpyrrolidinium bis(trifluoromethylsulfonyl) imide [C3C1Pyr][NTf2], 3-butyl-1,2-dimethylimidazolium bis(trifluoromethylsulfonyl) imide [C4C1C1Im][NTf2], 1-butyl-3-methylimidazolium iodide [C4C1Im][I], 3-hexyl-1-methylimidazolium iodide [C6C1Im][I], 3-methyl-1-propylimidazolium iodide [C3C1Im][I], 1-methyl-3-octylimidazolium trifluoromethanesulfonate [C8C1Im][OTF], 1-butyl-1-methylpyrrolidinium dicyanamide [C4C1Pyr][DCA], and 1-ethyl-3-methylimidazolium acetate [C2C1Im][C1COO] were determined in a wide P and T range by using a vibrating tube densimeter. It was observed density increase in the following order: [C4C1Pyr][DCA] < [C2C1Im][C1COO] < [C8C1Im][OTF] < [C6C1Im][I] < [C4C1C1Im][NTf2] < [C3C1Pyr][NTf2] < [C3C1C1Im][NTf2] < [(C2)3S][NTf2] < [C4C1Im][I] < [C3C1Im][I], according with their intermolecular interactions and structural packing efficiency. By using a Tammann-Tait equation, these experimental density data were correlated with an average absolute relative deviation (%AARD) less than 0.025 % for all ionic liquids studied. From this data, the following derivative properties were calculated: isothermal compressibility (κ_T), isobaric expansivity (α_p), thermal pressure coefficient (γ_v), and internal pressure (P_i). Furthermore, when comparing the average absolute relative deviation between experimental density and estimated by the group contribution models, it was observed that Paduszynski and Domanska model presented the best results, with average %AARD of 0.87%.