Structure Formation of Lsoporous Block Copolymer Membranes
报告人：Prof. Dr. Volker Abetz （汉堡大学/德国亥姆霍兹联合会吉斯达赫特中心）
报告人简介：
Volker Abetz教授1990年获得德国弗赖堡大学博士学位，先后在德国马普高分子研究所、美因兹大学、拜罗伊特大学等机构工作。2004年至2012年任德国基尔大学教授，2013年1月起转入德国汉堡大学化学部任教授。同时， 2002年至今Volker Abetz教授一直担任德国亥姆霍兹联合会吉斯达赫特研究中心高分子研究所所长。
报告内容：
Amphiphilic block copolymers can spontaneously form integral asymmetric isoporous membranes by evaporation-induced self-assembly. The parameters influencing the structure formation will be discussed. The critical structural evolution steps occur within the first hundred seconds after solvent casting. By using synchrotron small angle X-ray scattering employing a specially designed solvent casting apparatus, the kinetics of the structural evolution was monitored in situ. Sometime after solution casting first structural features on length scales of 30–70 nm are observed. During the subsequent period of solvent evaporation the length scales increase continuously towards a plateau value of 80–120 nm, depending on the molecular weight of the block copolymer. The time evolution of the characteristic length scales follow a simple exponential saturation curve for all block copolymers, irrespective of molecular weight, composition, and addition of salts. This is in agreement with theoretical models on two-dimensional ordered block copolymer domain formation. Furthermore, immersion in water during solvent evaporation leads to a nearly instantaneous increase of the characteristic length scale to its plateau value. The addition of salts leads to structures with smaller characteristic length scales, but still following the same kinetic evolution. Morphological results of membranes and dense bulk materials indicate a different dependence of the periodic length scale from the molecular weight, as shown by comparison of investigations by scanning, transmission electron microscopy and small angle X-ray scattering.
报告时间：2016年6月9日 下午15:00
报告地点：创意园327室
深圳大学材料学院
2016年6月7日
