METALLOCENE-BASED REDOX-SWITCHABLE SURFACTANTS FOR SEPARATIONS

SURFACTANT-BASED SEPARATION PROCESSES OFFER HIGH SELECTIVITY AND ENERGY EFFICIENCY, AND IMPROVED METHODS TO EFFICIENTLY FORM OR DISRUPT SURFACTANT-INDUCED STRUCTURES WOULD FURTHER IMPROVE PROCESS ECONOMICS. REDOX-SWITCHABLE SURFACTANTS ARE A NEW CLASS OF MATERIALS WHICH CAN BE ELECTROCHEMICALLY CYCLED BETWEEN SURFACTANT AND NON-SURFACTANT STATES, CONTROLLING SURFACTANT-INDUCED STRUCTURE IN A SELECTIVE AND EFFICIENT MANNER. THESE NEWLY DISCOVERED SURFACTANTS HAVE NOT YET BEEN APPLIED TO SEPARATION PROCESSES; FEW EXAMPLES HAVE BEEN SYNTHESIZED; AND THE RELATIONSHIP BETWEEN THEIR STRUCTURE AND SURFACTANT OR ELECTROCHEMICAL PROPERTIES IS NOT WELL UNDERSTOOD. RESEARCHERS ARE PREPARING SELECTED REDOX-SWITCHABLE SURFACTANTS, SYSTEMATICALLY VARYING CRITICAL STRUCTURAL PARAMETERS. THEY DETERMINE THE SURFACTANT AND ELECTROCHEMICAL PROPERTIES OF THESE MATERIALS, AND USE PRINCIPAL COMPONENT ANALYSIS TO IDENTIFY THE STRUCTURAL FEATURES MOST IMPORTANT IN DETERMINING THEIR PROPERTIES. ECONOMICALLY IMPORTANT SEPARATIONS IN WHICH THE UNIQUE PROPERTIES OF REDOX-SWITCHED SURFACTANTS WOULD BE MOST BENEFICIAL ARE IDENTIFIED.