Predicting Surface Tensions and Electrical Conductivities for High Molecular Weight Ionic Liquid Propellants Using Quantitative Structure-Property Relationships (QSPR)

Quantitative Structure-Property Relationships (QSPR) take in existing experimental property data and output predicted properties using statistical analysis and linear regressions. A priori, QSPR can provide practical results for ionic liquid (IL) propellants of any physical property, such as density, viscosity, surface tension, electrical conductivity, etc., as well as of any chemical property such as ignition delay time. It saves time and costly resources used when first synthesizing the IL and measuring its various properties to see if it meets mission requirements. QSPR also provides benefits over first principles theoretical computational methods such as increased accuracy and reduced computational time, therefore reducing the cost over current approaches in molecular dynamics simulations. In this work, QSPR was used to predict surface tensions and electrical conductivities of ionic liquids with high molecular weights. These high molecular weight ionic liquids are being investigated for applications in electrospray propulsion because of their omniphobicity and high short-term thermal stability characteristics, which potentially give them a performance advantage over existing propellants.