2.1 Database
A comprehensive experimental dataset was established by collecting the experimental data of three properties (density, viscosity, thermal conductivity) of ILs from the Ionic Liquids database provided by the National Institute of Standards and Technology (NIST) (https://ilthermo.boulder.nist.gov/index.html) and papers of Yan et al. and He et al.29,39,46 9020 density (ρ ) data points for 315 ILs, 7342 viscosity (ρ ) data points for 351 ILs and 608 thermal conductivity (λ ) data points for 87 ILs are covered in the dataset. For density, viscosity and thermal conductivity, the temperature and pressure ranges are (253.15-473.15 K) and (0.1-250 MPa), (253.15-438.15 K) and (0.06-300 MPa), (273.15-390 K) and (0.1-20.0 MPa), respectively.
The ILs are based on various cations such as imidazoulium (Im), pyridinium (Py), ammonium (Am), pyrrolidinium (Pyr), phosphonium (Ph), piperidinium (Pip), morpholinium (Mor), sulphonium (S), pyrrolidonium (N), diethylthiouronium (Thiur), 1,8-diazabicycloundecenium (Dbu), N-octylisoquinolinium (Quin), Caprolactam (Cp). And anions included tetrafluoroborate [(BF4)-], hexafluorophosphate [(PF6)-], dicyanamide [(N(CN)2)-], tetracyanoborate [(B(CN)4)-], trifluoroacetate [(C(CN)3)-], alkyl-phosphate [(RPO4)-], bis[(perfluoroethyl)sulfonyl]imide [(Pf2N)-], alkoxy-alkylsulfates [(RSO3)-], tris(pentafluoroethyl)trifluorophosphate [(FAP)-], alkyl-sulfate [(RSO4)-],thiocyanate [(SCN)-], carboxylicacid [(RCO2)-], bis[(trifluoromethyl)sulfonyl]imide [(Tf2N)-], halogen [(X)-], 1,2,3-triazolide [(Triz)-], Tetrazolide [(Tetra)-], difluoromono[1,2-oxalato(2-)-O,O’]borate [(RBF2)-], 4-nitropyrazolide [(4-NO2pyra)-], phenolate [(Phe)-], 2-(cyano)pyrrolide [(2-CNpyr)-]. The ILs name together with corresponding experimental values of density, viscosity and thermal conductivity were shown in Supporting Information Tables S1~S3.