YIP HARNASSING PHOTO-INDUCED PHASE TRANSITION OF ORGANIC MATERIALS FOR CATALYST RECYCLING
Abstract
Catalysis is one of the core processes in chemical industry and essential for achieving many products critical to the Department of Defense’s mission – from medicines to counter threats, to radiation-resistant polymeric coatings, and advanced fuels for aircraft. Catalysts are the key components that serve to improve reaction rates and product yields, and these costly compounds are generally disposed after one use. Various concepts for catalyst recycling, particularly using fluorous biphasic systems, have been developed to achieve cost-effective and sustainable synthetic procedures. However, the heating and cooling steps employed in the recycling process are only compatible with a limited scope of reactions and solvents. To address this challenge, we propose to develop a new class of biphasic catalysts that are optically activated, or precipitated, at a constant temperature by the incorporation of a photoswitch unit in the catalyst structure. Photoswitches are novel organic molecules that respond to light by changing their shape and physical properties including polarity. We hypothesize that a significant shape and polarity change of the photoswitch unit will drastically alter the degree of intermolecular interactions among the catalysts and between the catalysts and solvent molecules. This will in turn reversibly change the solubility of catalysts in an organic solvent, which regulates the activity and recovery of catalysts. In order to test this hypothesis, we will design catalyst structures bearing photoswitches and aggregation-inducing groups. We will use structure-property analysis to understand the impact of photo-induced shape changes on the intermolecular interactions that induce aggregation. Evaluation of catalysis will enable us to measure the solubility change of photo-switching catalysts, and the feedback loop between molecular design and catalysis will allow us to achieve a desired catalyst structure that is reversibly activated and precipitated for recoverable catalysis.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 07, 2023
- Source ID
- FA95502210254
Entities
People
- Grace Han
Organizations
- Air Force Office of Scientific Research
- Brandeis University
- United States Air Force