Chemical Separations Using Combined Structure Fluid Gradients and Countercurrent Field Flow Fractions

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ABSTRACT Proposal No: 9627453 Proposal Type: Investigator Initiated Principal Investigator: T. Alan Hatton Affiliation: Massachusetts Institute of Technology This grant is awarded through the Interfacial, transport and separations program of the Chemical and Transport Systems Division. The principal investigator is Dr. T. Alan Hatton of the Massachusetts Institute of Technology. The research addresses the development of a new technique applicable to many difficult chemical separation problems, particularly in low-volume high value-added applications. Externally-applied field gradients will be utilized to generate systems having lateral gradients in solution structure and hence in their interactions with specific solutes or particles. The differences in distribution of different solutes over such structured gradient solutions can be exploited in separation processes by using filed-flow fractionation concepts with imposed countercurrent flow. Certain block copolymer solutions, for instance, can undergo microphase transitions over a relatively narrow temperature range such that if a temperature difference is applied across the solution, micelles are formed in the warmer regions of the flow channel but are not formed in the colder parts of the solution. This could affect the distribution of hydrophobic solutes through solubilization within he micelle cores, or could lead to size exclusion of larger molecular species such as proteins and viruses. Another example would be the use of polymer-stabilized magnetic nanoparticles as separations media in a magnetic field gradient. Highly selective complexing agents, such as calixarenes or chiral surfactants, can be attached to these polymers to enhance the separation capabilities. These methods will have the significant advantages that the process may be operated continuously, it will be gentle and low in toxicity and may achieve high resolution even when the driving force for separation of two solutes is small. Potential applications include fine chemicals separations, the optical resolution of enantiomeric mixtures, protein separations, and virus purification. Vijay T. John, PD/CTS 03/27/97