On October 28th, invited by Professor Haifeng Yu of the Department of Materials Science and Engineering (MSE), College of Engineering, Professor Arri Priimagi of Tampere University of Technology (Finland) visited MSE and gave a lecture entitled “Halogen-Bonded Light-Controllable Materials”. Dozens of teachers and students attended the lecture.

Prof. Arri introduced the research work in his group, especially the recent research on supramolecular liquid crystal, which comprises of two nonmesogenic constituents that are complexed via halogen bonding. This spacerless complex uniquely combines efficient photo alignment (order parameters as high as 0.55 were induced into initially isotropic spin coated thin films upon irradiation with polarized light) and SRG formation (gratings with modulation depth of 600 nm were inscribed onto films with 250 nm thickness). On the other hand, halogen-bonded polymer-azobenzene complexes have allowed researchers to probe the dependence of SRG formation efficiency on the nature and strength of noncovalent interaction between the polymer host and the azobenzene units. This is important in view of gaining fundamental understanding on the light-induced mass transport process, which is not yet comprehensively understood.

These results comprise the very first examples of halogen-bond-based photoresponsive materials, and serve to demonstrate that halogen bonding makes a difference.

Prof. Arri’s lecture greatly inspired the interests of the students and professors on present. Following the talk, Prof. Arri met with many professors of MSE and exchanged thoughts on fields of common interests. Both parties expressed willingness of future cooperation.

Professor Arri Priimagi is currently an Assistant Professor in the Department of Chemistry and Bioengineering at Tampere University of Technology, Finland. He obtained a Master of Science and Technology degree from Tampere University of Technology in 2004, and then Doctor of Science and Technology degree from Helsinki University of Technology in 2009. After that he worked as a Post-doc researcher for five years in Aalto University, Tokyo Institute of Technology (Japan) and Politecnico di Milano (Italy) respectively, before taking the current position in September, 2014.