SGER: Liquid Crystals as Stimulus-Responsive Media for Dynamic Mediation of Chemical Separations, Application to Carbon Mitigation

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

ABSTRACT Proposal No.: CTS-0080915 Proposal Type: Investigator Initiated- SGER Principal Investigator: T. Alan Hatton Institution: Massachusetts Institute of Technology SGER: Liquid Crystals as Stimulus-Responsive Media for Dynamic Mediation of Chemical Separations This project explores new concepts for the dynamic mediation of chemical separations by use of liquid crystals as adsorbents. With these materials small changes in external stimuli can cause major changes in fluid or interfacial structure that change significantly the capacity of the separations media for targeted solutes. Specifically, the influence of changing electric or magnetic fields on thermotropic liquid crystals near their smectic/nematic/isotropic transition regions is exploited to control the capacity and selectivity of gas separations. This work is intended to provide an initial assessment of the feasibility of such an approach, primarily in determining what factors affect solubilization capacity and release profiles and to determine the sensitivity and robustness of the method to temperature fluctuations. Consideration is given to strategies for implementation of this concept in large-scale chemical processes. Tunable separation media could find major implementation in tackling global problems associated with greenhouse gas mitigation and in performing sensitive chemical separations in the fine-chemical and pharmaceutical areas. The ability to vary electric and magnetic fields rapidly and dynamically could provide additional process flexibility beyond the usual temperature and pressure changes used to drive many gas separation processes, and a greater degree of control over process operations is anticipated. A second area of potential applications is in the control of separations in microchemical devices, where the sub-millimeter dimensions are such that high electric fields and sensitive temperature control can be readily attained.