Hydrophobic trioctylammonium-based ionic liquids (ILs) were synthesized for heavy metal extraction from aqueous solutions. The ILs were characterized using ¹H NMR, ¹³C NMR, and FT-IR spectroscopy, confirming the synthesis of the ILs. The thermal stability of the ILs was investigated using thermogravimetric analysis, and the synthesized ILs had decomposition temperatures between 205 and 222 °C. The temperature dependences of density, viscosity, and electrical conductivity for the liquid ILs were investigated in the temperature range of 293.15–333.15 K and modelled using a linear model, the Vogel–Fulcher–Tammann model, and the Arrhenius model, respectively. The efficacy of [HTOA][phthalate] and [HTOA][adipate] as extraction solvents in liquid–liquid extraction of Cd(II), Cu(II), and Zn(II) from aqueous solutions was then determined by investigating the effect of extraction time on the extraction process, with four extraction times being used: 5, 15, 30, and 60 min. [HTOA][adipate] performed better than [HTOA][phthalate], having extraction efficiencies of 85, 67 and 69% for Cd(II), Cu(II), and Zn(II), respectively, after 60 min. In comparison, [HTOA][phthalate] had extraction efficiencies of 85, 53, and 37% for Cd(II), Cu(II), and Zn(II), respectively, after 60 min. The recyclability of the [HTOA][adipate] was investigated by using 0.1 M EDTA solution as the regenerating agent. The EDTA solution was effective in extracting Cd(II) and Cu(II), with back-extraction efficiencies of 89 and 82%, respectively. Its extraction of Zn(II) was less effective with a back-extraction efficiency of 41% being achieved.

疏水性三辛基铵基离子液体 (IL) 被合成用于从水溶液中提取重金属。ILs 使用¹ H NMR、¹³C NMR 和 FT-IR 光谱，证实了 ILs 的合成。使用热重分析研究了离子液体的热稳定性，合成离子液体的分解温度在 205 到 222 °C 之间。在 293.15-333.15 K 的温度范围内研究了液体 IL 的密度、粘度和电导率的温度依赖性，并分别使用线性模型、Vogel-Fulcher-Tammann 模型和 Arrhenius 模型进行建模。[HTOA][邻苯二甲酸酯]和[HTOA][己二酸]作为萃取溶剂在从水溶液中液-液萃取Cd(II)、Cu(II)和Zn(II)时的效果通过研究效果来确定提取过程中的提取时间，使用了四个提取时间：5、15、30 和 60 分钟。[HTOA][己二酸] 的性能优于 [HTOA][邻苯二甲酸酯]，60 分钟后对 Cd(II)、Cu(II) 和 Zn(II) 的提取效率分别为 85%、67% 和 69%。相比之下，[HTOA][邻苯二甲酸酯] 在 60 分钟后对 Cd(II)、Cu(II) 和 Zn(II) 的提取效率分别为 85%、53% 和 37%。通过使用 0.1 M EDTA 溶液作为再生剂研究了 [HTOA][己二酸] 的可回收性。EDTA 溶液可有效萃取 Cd(II) 和 Cu(II)，反萃取效率分别为 89% 和 82%。它对 Zn(II) 的提取效果较差，反提取效率为 41%。60 分钟后分别为 Cu(II) 和 Zn(II)。通过使用 0.1 M EDTA 溶液作为再生剂研究了 [HTOA][己二酸] 的可回收性。EDTA 溶液可有效萃取 Cd(II) 和 Cu(II)，反萃取效率分别为 89% 和 82%。它对 Zn(II) 的提取效果较差，反提取效率为 41%。60 分钟后分别为 Cu(II) 和 Zn(II)。通过使用 0.1 M EDTA 溶液作为再生剂研究了 [HTOA][己二酸] 的可回收性。EDTA 溶液可有效萃取 Cd(II) 和 Cu(II)，反萃取效率分别为 89% 和 82%。它对 Zn(II) 的提取效果较差，反提取效率为 41%。