We use multiple characterization methods, including viscosity, ionic conductivity, density, and surface tension measurements, to investigate the unusual transport behavior of multiple tetra-alkyl-phosphonium-2-cyano-pyrrolide ([P-nnnm](-)[2CNPyr]) ILs in glycerol and triethanolamine solvents. Specifically, the viscosity goes through a maximum for all of the IL/glycerol and IL/triethanolamine mixtures, which cannot be explained by traditional mixing rules. Through conductivity and surface tension characterization we find substantial evidence of microstructure formation driven by the amphiphilic structure of the tetra-alkyl-phosphonium ([P-nnnm](+)) cation accounting for the uncommon viscosity behavior. While micelle formation is well-known for IL+ water systems, the observation of these microstructures in nonaqueous systems is a significant discovery. The slope of the ionic conductivity as a function of IL concentration changes substantially at the critical aggregate concentration cac, at which point the ILs undergo solvophobic self-assembly; this phenomenon is observed in all IL/solvent mixtures investigated. The cac is observed at more dilute IL concentrations for ILs containing longer alkyl chains. Furthermore, we observe lower cac values in glycerol compared to that of triethanolamine, owing to its higher dielectric constant and larger cohesion energy, as measured by the Gordon parameter.