报告题目：Biomimic and Stimuli-Responsive Macromolecules
报告人： 张阿方 上海大学教授
主持人： 程义云 教授
报告时间：11月21日 14:00（周三）
报告地点：生科院大楼469会议室

报告人简介：张阿方，教授，博士生导师，入选2011年度上海浦江人才计划。分别从中国科技大学、北京大学获得硕士及博士学位。2005年7月到2009年12月在苏黎士瑞士联邦理工学院任资深研究员，2005年至2008期间兼任郑州大学河南省高分子化学和物理特聘教授。2009年底回国到上海大学任教。主持三十余项科研项目及课题，包括国家自然科学基金重点项目、“八五”重点科技攻关项目、瑞士国家自然科学基金项目、苏黎士瑞士联邦理工学院资助课题、河南省重大科技攻关项目等。科研成果获省级科技进步二等奖四项、三等奖多项。三项国家发明专利获授权。JACS和Macromolecules等著名刊物上在包括Adv. Mater., Angew. Chem. Int. Ed., Chem. Commun., Chem. Eur. J., 发表学术论文六十余篇。主要从事新型聚合物的分子设计与合成、分子纳米材料、智能材料等方面的研究工作，目前主持承担有国家基金委重点项目及上海市科委重点项目等。
报告内容简介：This talk will include the following three parts: (1) Ordered secondary structures of peptides in nature, such as a-helices and b-sheets, play crucial role in forming organized tertiary structures of proteins, which dominate their functions and properties as well as their biological activities. The stabilization of these secondary conformations will not only guarantee the proper activities of the proteins but also prevent them from forming abnormal amyloid fiber aggregates. Peptide-based polymers combine the structural characteristics and properties from both peptides and polymers, thus, are promising for applications at various areas. At the same time, the polymer architecture may also show influence on the ordered structures of the peptide units. Therefore, we here report on several examples developed recently from our group to show how architecture exhibit effects on stabilizing the secondary structures of peptides, and how the ordered structures of peptides are mediated by local environmental variation within the polymer matrix. (2) Chiral helical polymers have received considerable attention in recent years not only by mimicking the structures and functions of biological helices, but also due to their unique optical properties as well as molecular recognition ability. We here report our recent progress on developing novel chiral and helical polymers based different methodology. (3) Responsive behavior is rather typical for biomacromolecules and has been mimicked in fields ranging from advanced artificial devices, smart surfaces and sensors to medicine and biomineralization. It presents a substantial scientific and engineering challenge with a considerable application potential. An interesting class of stimuli-responsive materials is thermoresponsive synthetic polymers. They are water-soluble at room temperature but start to collapse close to their lower critical solution temperatures (LCSTs) due to dehydration of the chains, and subsequently form aggregates. The LCST of a polymer is not only dependent on the balance of the hydrophilic and hydrophobic units, with the more hydrophilic polymers commonly showing higher LCSTs than the more hydrophobic ones, but also on how these units are incorporated into the molecular structure. Here we describe the efficient synthesis of a series of first (G1) and second (G2) generation thermoresponsive dendronized polymers and dendrimers based on oligoethylene oxide (OEO) as linking and gallic acid as branching unit (see figure). The LCSTs of these macromolecules can be tuned from 27 oC to 64 oC by modification of the peripheral units, OEO length or the dendron generation. Their thermally induced phase transitions as well as aggregations will be addressed. This includes their fast and sharp transition with virtually no hysteresis between heating and cooling process. Interestingly, the unprecedented thermoresponsiveness based on OEG-dendritic scaffolds have been also realized via supramolecular interactions. Besides, all of the macromolecules show negligible in vitro cytotoxicity, except G1 dendrimers. We believe to have a versatile and powerful “smart” system at hand which eventually will span considerable applications in the material or biomedicine areas.