The PI has successfully completed the research project. A new hydrophobic ionic liquid ferrofluid was synthesized considering potential applications under no atmosphere and in high temperature conditions. The polymer, which stabilizes the nanoparticles in the ionic liquid, can be designed to obtain the desired level of steric repulsion between particles using the predictions from the DLVO theory. The binding strength of the polymer to the nanoparticles can also be adjusted by selecting appropriate polymer blocks with multiple anchoring points. The magnetorheological behavior of the new hydrophobic ILFF evidenced that the AA10-DEAm60 diblock stabilizes the nanoparticles against aggregation of particles arising due to magnetic dipole-dipole attractive forces. Increasing the applied magnetic field strength and particle concentration in the IL increased the elastic modulus, which is a useful property for applications involving variable force fields. The shear thinning nature of the ferrofluid makes it a suitable candidate for applications involving pumping and spaying. Calculations revealed that the length of the DEAm60 segment of the polymer gave a sufficiently large steric repulsion against localized thickening of the ILFF under high shear forces. The relaxation behavior of the ferrofluid and methods to control the relaxation should be studied to use the ferrofluid in engineering applications such as electrospraying from magnetic ferrofluid spikes. There was one peer reviewed paper submitted as a direct result of the grant award.