Use of photoacids and photobases for making smart functional systems

16/07/2023

Chemistry Faculty Seminar Room

12:30

Anna Yucknovsky Amdursky’s group, Schulich Faculty of Chemistry, Technion

Physical-Chemistry Seminar

Use of photoacids and photobases for making smart functional systems

Ph.d. Final exam

Use of photoacids and photobases for making smart functional systems

Anna Yucknovsky

Under the supervision of Prof. Nadav Amdursky

Biological systems are considered smart due to their ability of sensing, communication, self-organization and self-regulation. This complexity of nature is our inspiration for making artificial smart systems based on stimuli-responsive materials1. These materials can respond to external stimuli, including temperature, chemical signals or pH. An energy supply is required to generate the stimuli and achieve dynamic behavior in artificial systems. In that context, light can deliver energy and act as a physical stimulus; furthermore, it can be transformed into a chemical stimulus by molecules, which undergo chemical changes upon light absorption. In our research, we are working with a class of molecules named photoacids and photobases. These molecules can become strong acids and bases only upon light absorption and, consequently, change the pH of the surrounding2. Hence, they can be considered good candidates for mediating light stimulation into pH-sensitive processes.

My talk will deal with light-controlled dynamic chemical systems involving the use of photoacids and photobases. We have developed several dynamic systems with versatile functionalities, including oil droplets capable of self-propulsion and electrochemical cell with switchable current polarity3, 4. On the molecular scale, we’ve developed a chemical reaction with controllable pathways.

Our conclusion is that possible applications of photoacids and photobases for developing smart materials are diverse because they can reversibly induce changes in any pH-sensitive system.

  1. Zhang, X.; Chen, L.;  Lim, K. H.;  Gonuguntla, S.;  Lim, K. W.;  Pranantyo, D.;  Yong, W. P.;  Yam, W. J. T.;  Low, Z.;  Teo, W. J.;  Nien, H. P.;  Loh, Q. W.; Soh, S., The Pathway to Intelligence: Using Stimuli-Responsive Materials as Building Blocks for Constructing Smart and Functional Systems. Adv. Mater. 2019, 31 (11), 1804540.
  2. Pines, D.; Pines, E., Solvent Assisted Photoacidity. In Hydrogen‐Transfer Reactions, 2006; pp 377-415.
  3. Yucknovsky, A.; Rich, B. B.;  Westfried, A.;  Pokroy, B.; Amdursky, N., Self-Propulsion of Droplets via Light-Stimuli Rapid Control of Their Surface Tension. Adv. Mater. Interfaces 2021, 8 (22), 2100751.
  4. Yuchnovsky, A.; Shlosberg, Y.;  Adir, N.; Amdursky, N., Photocurrent Generation and Polarity Switching in Electrochemical Cells through Light‐induced Excited State Proton Transfer of Photoacids and Photobases. Angew. Chem. 2023, e202301541.