My research involves the investigation of magnetic surfactants for oil recovery applications. Specifically, I am involved with the synthesis and property characterization of cationic and anionic single molecule surfactants, as well as polymeric surfactants. Some of the surfactant properties that I characterize are: the critical micelle concentration (CMC) though conductivity and tensiometric measurements, degree of micelle counterion binding via solution conductivity measurements, redoxable properties via electrochemical methods, and micelle size via dynamic light scattering measurements. Some of our previous research investigating the electrochemical properties of aqueous solutions of certain single molecule magnetic surfactants found in the literature has cast doubt upon their stability, so I also investigate the stability of our magnetic surfactants while in solution.
My research involves the synthesis of both cationic (Type I) and chelated (Type II) magnetic surfactants, and the measurement of their response to parallel external magnetic fields. When a solid magnetic surfactant is dissolved in water, it forms a paramagnetic fluid that responds to external magnetic fields yet retains the interfacial properties of a surfactant. A simple and reliable way to quantify this response is to measure the change in surface tension that occurs inside and outside of a known, uniform parallel magnetic field by using a pendant drop technique. As magnetic surfactant molecules approach the surface of a drop of aqueous solution, the surface tension is reduced due to migration of surfactant molecules to the air-water interface. A further reduction in surface tension is seen when the drop is placed within an external magnetic field, meaning that the migration of magnetic surfactants to the interface is enhanced in response to the magnetic field. Thus, the response of these unique surfactants at the molecular level can be “tuned” by simply adding or removing an external magnetic field. This in turn offers the possibility of tailored, low-energy separations at the molecular scale utilizing magnetically-responsive surface-active materials.