Gels for molecular recognition, accumulation and release. Final report, grant from DOE

Abstract

The proposal was to establish a general principle with which polymer gels can specifically recognize a target molecule and reversibly change their affinity to the target by orders of magnitude. The polymer consists of two species of monomers, each having a different role. The majority monomer species control network density and make the gel to swell and shrink reversibly in response to an environmental change such as temperature. The minority monomers come into sufficient proximity to each other when the supporting gel shrinks and then they become able to function as multi-group absorption centers for the target molecules. This absorption can be switched on and off by the reversible gel phase transition. The multiple point absorption is the key, not only for reversibility, but also an essential ingredient for possible specificity of target recognition by polymers. Multivalent metal ions and multicharged pyranine are used as target molecules to demonstrate the principles, although the method will be applicable to a wide range of target molecules. The project established and demonstrated the guiding principles for design and synthesis of molecular recognition gels. Such gels should find use in a wide variety of applications including cleaning and recovery of chemicals from toxic waste,more » recovery and concentration of precious molecules from ocean and biological products and catalysis of chemical reactions.« less