Day 1 :
Muroran Institure of Technology
Keynote: Emerging conjugated Stretched and Contacted Helices of Substituted Polyacetylenes Prepared with an Organo-rhodium Catalyst
Time : 00:00
He has completed his PhD at the age of 28 years from Hokkaido University, Japan and postdoctoral fellows from United Kingdom and Sweden. After that he became assistant professor and associated Professors at Hokkaido University, and Professor of Muroran Institute of Technology, Japan. Furthermore he also became a senior research director at National Institute of Advanced Industrial Science & Technology (AIST) at Tsukuba, Japan, and Guest Professor at Paris University in France
The highly stereoregular preparation of mono-substituted polyacetylenes (SPA)s was performed using an [Rh(norbornadiene)Cl]2-triethylamine catalyst to give the π-conjugated helical polymers. Because the SPAs are expected as new advanced materials due to semiconductivity, NLO properties, external stimulus responsibility, enantioselectivity, and oxygen permeability. These properties are strongly related to the geometrical structure, e.g., cis or trans forms and higher-order structure, e.g., p stacking along with the helical main-chain in the solid phase. Therefore, we have investigated whether the geometrical and helical structures of the SPAs can be controlled through molecular design and/or external stimuli. The p-n-hexyloxyphenylacetylene (pPA) monomer was stereoregularly polymerized using the Rh catalyst at 25 °C. When ethanol and n-hexane were used as the polymerization solvents, a yellow P(Y), and its red P(R) were obtained, respectively. The diffuse reflective UV-vis spectra of these polymers showed lmax at 445 and 575 nm, respectively. The WAXS patterns of P(Y) and P(R) exhibited hexagonal columnar structures which were attributed to the stretched and contracted helices, respectively. Additionally, P(Y) was irreversibly transformed into a reddish-black P(Y➞B), whose columnar diameter was identical to that of P(R) when heated at 80 °C for 1 h. These findings suggest a thermally irreversible rearrangement from a thermally unstable P(Y) with a stretched helix to a stable P(Y➞B) with a contracted helix. In the case of aliphatic polyacetylene ester the mutual helical oscillation between the contacted and stretched helices was found in the solution1
University College London
Dr Junwang Tang is the Director of UCL Materials Hub, Professor of Chemistry and Materials Engineering in the Department of Chemical Engineering, and a Fellow of the RSC. He received his PhD in Physical Chemistry in 2001. After that, he took a JSPS fellow in Japan and senior researcher in Imperial College London. Later, he joined the Department of Chemical Engineering at University College London to take a permanent faculty position.
He currently leads a research team including postdoctoral researchers, academic visitors and research students with financial support from UK EPSRC, Leverhulme, Royal Society, Royal Academy of Engineering, Newton Fund, EU PF7, Qatar and so on. His research interests encompass structure-controlled nanomaterials synthesis by a flow system powered by microwave irradiation, solar H2 synthesis from water, CO2 conversion to a renewable fuel, methane conversion, ammonia synthesis and photocatalytic environmental purification. Such studies are undertaken in parallel with the mechanistic understanding and device optimisation to address the renewable energy supply and environmental purification. His research has led to ~110 journal papers with >7000 citations, 11 patents and many invited lectures in the international conference. He is the Editor-in-Chief of the Journal of Advanced Chemical Engineering, an Associate Editor of Asia-Pacific Journal of Chemical Engineering, the guest Editor-in-Chief of the International Journal of Photoenergy, 2012 and Associate Editor of Chin J. Catalysis apart from sitting on the editorial board of other international journals.
Catalytic decontamination of water by solar energy has attracted substantial interest over the past decades. However to develop an efficient photocatalyst for such environmental purification, in particular water treatment still remains a big challenge, involving Material Science, Chemistry, Engineering and Physics. In particular there is not a cost effective way to deal with large volume of water contaminated by small amount of organic substance or extreme large amount of contaminated water in suburban region (e.g. oil spill in Mexico Gulf, in China Bohai Sea).
Inorganic photocatalysis using solar energy to mineralize organic contaminants in principal is the potentially best solution to these issues and works in the cost effective way. Recently we preliminarily illustrated the key factors dominating the efficiency of process driven by light irradiation.1 Following that, water treatment was carried out in my group which is a challenging topic due to its complexity. In this talk, the mechanism of the chemical process, involving charge transfer and reaction with oxygen, will be addressed and structured/junction material development will be presented, resulting into a few times higher activity for textile water treatment2,3 and simulated river water treatment4,5 compared with the benchmark photocatalyst P25. Furthermore, a new and facile method to synthesize these active photocatalysts will be discussed