The innovation engine for new materials

Rengaraj Gopal

Rengaraj Gopal


Chalmers University of Technology


Materials Chemistry


Angelique Scheuermann

Faculty Sponsor(s): 

Javier Read de Alaniz
Christopher Bates

Faculty Sponsor's Department: 

Chemistry and Biochemistry

Project Title: 

Synthesis of light-responsive polymeric ionic liquids using an azobenzene photoswitch

Project Description: 

The growing energy demands have made the need for efficient energy storage and conductive materials very crucial. Polymeric ionic liquids (PILs) display great potential as solid electrolytes in batteries and fuel cells, due to their ability to combine advantageous attributes of both ionic liquids (low vapor pressure, thermal and chemical stability, broad electrochemical window) and synthetically tunable physical properties of polymers. A reversible azobenzene photoswitch was incorporated into the PIL, to affect its mechanical and electrical properties with light. The change in volume of azobenzene during light-stimulated trans-to-cis isomerization was utilized to alter the mobility of ions in the PILs. Light has better temporal and spatial control than heat and was preferred for the isomerization of the azobenzene photoswitch. Monomers were synthesized using air and water-free Schlenk line techniques, purified using column chromatography, and analyzed using nuclear magnetic resonance spectroscopy (NMR). Reversible Addition-Fragmentation chain-Transfer (RAFT) technique was used to polymerize the monomers and to achieve low polydispersity. Future work includes light-based studies of the PILs to determine the effects of the azobenzene photoswitch on PIL mechanical and electrical properties.