The solubility data of carbon dioxide (CO₂) in the new synthesized protic ionic liquids (PILs), diisopropylethylammonium propanoate [DIPEA][C₂COO] and diisopropylethylammonium butanoate [DIPEA][C₃COO] have been measured at temperatures range from 303.2 K to 348.2 K and pressures up to 7.04 MPa with a synthetic method. The solubility of CO₂ in [DIPEA][C₂COO] are found to be much higher than that of [DIPEA][C₃COO], about three folds, under the same temperature and pressure. The solubility data of CO₂ + [DIPEA][C₂COO] were correlated by using the Peng-Robinson equation of state with the temperature-dependent two-parameter van der Waals one-fluid mixing rules. Moreover, the interactions among CO₂ and the PIL ions were explored by molecular dynamics (MD) simulation at ambient conditions. The effect of the dissolved CO₂ in the PILs on the intermolecular hydrogen bonds between the ammonium hydrogen of the PIL cation and carboxylate oxygen of the anion was also investigated.

在303.2的温度范围内测量了二氧化碳（CO ₂）在新合成的质子离子液体（PIL），丙酸二异丙基乙基铵[DIPEA] [C ₂ COO]和丁酸二异丙基乙基铵[DIPEA] [C ₃ COO]中的溶解度数据。使用合成方法，可将K压缩至348.2 K，压力可达7.04 MPa。发现在相同温度和压力下，CO ₂在[DIPEA] [C ₂ COO]中的溶解度比[DIPEA] [C ₃ COO]高得多，约为三倍。CO ₂  + [DIPEA] [C ₂的溶解度数据通过使用状态的Peng-Robinson方程与温度相关的两参数van der Waals一流体混合规则将COO]关联起来。此外，通过在环境条件下的分子动力学（MD）模拟，探索了CO ₂和PIL离子之间的相互作用。还研究了PIL中溶解的CO ₂对PIL阳离子的铵氢与阴离子的羧酸氧之间的分子间氢键的影响。