(26c) 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.