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关于举行美国阿克隆大学刘天波教授学术报告的通知

时间:2019-06-14 16:22      发布人:何秋云      阅读:110

报告题目:Hydrophilic Macroions – What Happens When Soluble Ions Reach the Nanometer Scale?

报 告 人:刘天波 教授美国阿克隆大学

邀 请 人:唐本忠 院士

报告时间:2019年6月18日(周二)下午15:00

报告地点:北区发光材料与器件国重 502会议室

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报告摘要:

Between traditional simple ions and large colloidal particles, we found that there exists a transitional stage – macroionic solutions. In this regime the charged solutes have solution behavior fundamentally different from the above two categories. The best model macroions are structurally well-defined molecular clusters with accurately tunable charges, such as inorganic clusters, metal-organic cages (MOC), CD, dendrimers and globule proteins. Such macroions tend to strongly attract with each other although they carry the like charges, and demonstrate unique self-assembly behaviors involving counter-ion-mediated attraction. In dilute solutions, they tend to reversibly self-assemble into single-layered, hollow, spherical “blackberry” structures while the assembly size can be accurately controlled by solvent content, macroionic charge density or pH. The long-range electrostatic interaction makes the inter-macroionic distance in the blackberry structures tunable within certain range, with smaller distance leading to larger assembly size. The blackberry type structure represents a universal, free-energy favored state of soluble macroions with moderate charge, and mimics some biological processes, such as the virus capsid shell formation. The macroions can also be used as simple models to understand some fundamental biological behaviors such as the self-recognition and chiral selection of biological assemblies.

An interesting observation is that the MOCs containing AIEgens first made by Huang and Stang. We notice that such cages are also macroions, while their self-assembly into blackberry type structures resulting in longer intermolecular distance than that of traditional AIE (controlled by van der Waals forces), and consequently longer and tunable emission wavelengths. Such solutions are still very stable while the emission seems to be quite strong. With two TPPEs incorporated in the same cage, the constrained intramolecular interaction between the TPPEs also shows significant emission wavelength shift controlled by the solvent polarity.

 

个人简介:

Tianbo Liu received his B. S. degree from Peking University, China in 1994 and his Ph.D. in Physical Chemistry from Stony Brook Univesity in 1999 (advisor Benjamin Chu). After spending two more years in the same group as a postdoctoral associate, he started his independent research career at the Physics Department, Brookhaven National Laboratory in 2001. In January 2005 he moved to Lehigh University as an assistant professor of Chemistry, and was promoted to associate professor with tenure in 2009 and full professor in 2012. Since January 2013 he has been the A. Schulman Professor in the Department of Polymer Science, The University of Akron, and is serving as the Department Chair since July 2018. His laboratory focuses on understand the fundamental behaviour of complex solutions, especially hydrophilic macroions, inorganic-organic hybrid materials and other colloidal and biological systems.