Scholarlink

<p>Hydrophobic deep eutectic solvents (HDESs) have emerged as promising alternatives to conventional solvents because of their tunable structures and ecologically benign nature. The present study focuses on a series of carboxylic acid-based HDESs synthesized using hexanoic acid (HA), octanoic acid (OA), and decanoic acid (DA), combined with di(2-ethylhexyl) phosphoric acid (DEHPA)/Citronellal. Their structural, thermal stability, and physicochemical properties were systematically investigated. <sup>1</sup>H NMR and FTIR spectroscopy confirmed H bonding interactions between HBDs (hydrogen bond donors) and HBAs (hydrogen bond acceptors), as indicated by characteristic shifts and broadening in the -C=O, -O–H, and -P=O stretching regions. Thermogravimetric analysis (TGA) reveals that DA-based HDESs exhibit superior thermal stability relative to HA-based analogues, as reflected by significantly higher decomposition temperatures of 439.21&#xa0;K for DEHPA:DA and 385.70&#xa0;K for Citronellal:DA, compared to 350.64&#xa0;K for DEHPA:HA and 375.18&#xa0;K for Citronellal:HA. Physicochemical properties, including density (<i>ρ</i>), dielectric constant (<i>ε</i>), refractive index (<i>n</i><sub><i>D</i></sub>), and viscosity(<i>η</i>), were estimated in a range of temperatures 298.15&#xa0;K to 328.15&#xa0;K. In all systems, density, dielectric constant, refractive index, and viscosity decreased with increasing temperature. The results highlight that DEHPA:HA and Citronellal:HA show the highest density and dielectric constant values among their respective systems. In the case of refractive index and viscosity, DEHPA:DA and Citronellal:DA exhibit the highest values with respect to their OA and HA combinations.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Spectral insights, thermal stability, and physicochemical properties of aliphatic acid (C6, C8, and C10)-based hydrophobic deep eutectic solvents

  • 期刊论文

  • 发表日期：

    2026年6月24日

查看全文
  • Samaresh Maharana,
  • Sujata Mishra

摘要

Hydrophobic deep eutectic solvents (HDESs) have emerged as promising alternatives to conventional solvents because of their tunable structures and ecologically benign nature. The present study focuses on a series of carboxylic acid-based HDESs synthesized using hexanoic acid (HA), octanoic acid (OA), and decanoic acid (DA), combined with di(2-ethylhexyl) phosphoric acid (DEHPA)/Citronellal. Their structural, thermal stability, and physicochemical properties were systematically investigated. 1H NMR and FTIR spectroscopy confirmed H bonding interactions between HBDs (hydrogen bond donors) and HBAs (hydrogen bond acceptors), as indicated by characteristic shifts and broadening in the -C=O, -O–H, and -P=O stretching regions. Thermogravimetric analysis (TGA) reveals that DA-based HDESs exhibit superior thermal stability relative to HA-based analogues, as reflected by significantly higher decomposition temperatures of 439.21 K for DEHPA:DA and 385.70 K for Citronellal:DA, compared to 350.64 K for DEHPA:HA and 375.18 K for Citronellal:HA. Physicochemical properties, including density (ρ), dielectric constant (ε), refractive index (nD), and viscosity(η), were estimated in a range of temperatures 298.15 K to 328.15 K. In all systems, density, dielectric constant, refractive index, and viscosity decreased with increasing temperature. The results highlight that DEHPA:HA and Citronellal:HA show the highest density and dielectric constant values among their respective systems. In the case of refractive index and viscosity, DEHPA:DA and Citronellal:DA exhibit the highest values with respect to their OA and HA combinations.