Development of Magnetic Field-Responsive Surfactants

Development of magnetic field-responsive surfactants

Sun Hae Ra Shin¹, Rajiv Misra², Peter Schiffer², Kyle Bishop¹*

¹Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802

² Department of Physics, The Pennsylvania State University, University Park, PA 16802

*Address correspondence to kjmbishop@engr.psu.edu

This talk presents the development of magnetic field-responsive surfactants that can be used for dynamic and continuous tuning of interfacial properties. The magnetic surfactants consist of inorganic nanoparticles with amphiphilic surfaces. Particles of magnetic materials such as cobalt ferrite exhibit large magnetic moments and can be oriented and positioned by externally applied fields. The preparation of amphiphilic surface is readily achieved by spontaneous self-organization of a mixed monolayer of hydrophobic and hydrophilic ligands on the particle surface. Strong coupling between the particles' internal magnetic moments and their asymmetric surface chemistry allows external magnetic fields to directly influence the properties of the interface through the competition of magnetic and surface forces. The field-induced response of liquid interfaces containing these responsive surfactants is investigated with pendant drop tensiometry.