4. Conclusions
In this paper, three groups of norm descriptors were established by the
structure of ILs, anion and anion. Based on 9020 ρ data points,
7324 η data points and 608 λ data points, three QSPR
models were established to calculate the properties of ILs (density,
viscosity and thermal conductivity) at variable temperatures and
pressures. The performance of the f -T -P QSPR models
was improved by introducing norm descriptors into temperature and
pressure terms. The statistical results indicate that these models have
good prediction accuracy and credibility with the high R2 of 0.9966, 0.9676 and 0.9847, the low AARD of
0.48 %, 3.91 % and 1.02 % for predicting the density, viscosity and
thermal conductivity, respectively. Validation analysis shows that these
QSPR models have good prediction ability and robustness. Moreover,
parameters (α , β , γ and χ ) of thef-T-P model for 16329 ILs are predicted by QSPR models and most
of the predictions of density and viscosity values of ILs at variable
temperature and pressure are within a reasonable range, except for
[bmim][FS], [Hprthiur][I],
[mC10im][Pf2N],
[N113(eOH)][FAP] and
[odbu][C8SO3]. At variable
temperature and atmospheric pressure, the predicted thermal
conductivities of most ILs are in a reasonable range. At variable
temperature and pressure, the predicted thermal conductivity of these
ILs corresponding to seven anions are within the reasonable range, and
the predictions of these ILs corresponding to four cations and six
anions are not in the reasonable range. The prediction results show that
the model is stable and widely used.