Featured Postdoc (Travel grant winner): Dr. Paul Brown

Dr. Paul Brown was awarded a PDA travel grant for the Jan-June 2015 cycle.








BIO: Dr. Paul Brown obtained his Msci in Chemistry from the University of Bristol, UK. After a small break he then returned to Bristol to complete his postdoctoral studies under the supervision of Prof. Julian Eastoe and Dr Craig Butts. His Ph.D. work focused on developing magnetic surfactants suitable for bimolecular manipulation and separations. He is currently working as a postdoctoral associate in the group of Prof. T. Alan Hatton in the Department of Chemical Engineering. His research interests include the design and synthesis of ionic liquids for CO2 capture and various electrochemical activities for energy applications.

RESEARCH OVERVIEW: Surfactants are employed in all areas of science to generate self-assembly structures to stabilize interfaces, improve solubilization, and tailor biological and physicochemical properties. By creating stimuli responsive, and more recently, reactive surfactants it is possible to activate changes more sophisticatedly, without irreversible alterations in system composition and without significant energy input. CO2-switchable surfactants based on the reaction of CO2 with built in functional groups such as amines and amidines to form amidinium bicarbonates, zwitterionic adducts or ammonium carbamates have recently received much interest as CO2 exhibits good biocompatibility and is non-toxic and abundant. However, on the molecular level all the mechanisms rely on switching “on” and “off” of the surfactant. Our research demonstrates a new class of CO2-reactive ionic liquid surfactants where the counterion is the responsive species, allowing for fine tunability of surfactant properties. We investigate how alteration in the surfactant architecture and electrostatics after reaction with CO2 feeds through to significant changes in micellar structure as well as surface tension in a way not seen by any other surfactants. This may be put into effect in various colloidal systems ranging from microemulsions to polymers suitable for applications in enhanced oil recovery, catalysis, CO2-capture and novel ionic liquid separations. And, in particular relevance to gene therapy and targeted drug delivery, we are investigating surfactant binding to DNA (and other biomolecules) and reversible compaction on bubbling with CO2 and N2.