Topic: From Organic Monolayers to Functional Microapsules

Speaker: Helmuth Möhwald

Date: October 30 (Friday), 2 p.m.
Location: Room 1006, Wangkezhen Building
Host: Zhifei Dai

Abstract:

Much has been learnt in recent years to study and control the structure of organic molecules at interfaces, and an especially interesting interface has been that of liquids, because they enable the movement of molecules while ordering and exhibit no ordered substrate interactions. This will be briefly reviewed, making use of new techniques like grazing incidence diffraction , optical microscopy and FTIR spectroscopy. Here the systems range from simple amphiphile monolayers to biologically relevant molecules like phospholipids and peptides.

With the knowledge on organic monolayers one can build up organized films, and one of the most versatile techniques is that of building multilayers by consecutive adsorption of oppositely charged polyelectrolytes. This technique can be extended to coat colloids, and after core removal one obtains microcapsules with walls defined with nm precision. The permeability and the mechanics of these shells can be manipulated in a controlled way by external fields, pH, salt and temperature, and this can be made use of in many applications. We will specifically concentrate on applications as self-repairing coatings as well as light induced release to study immune response.

By ultrasonic treatment a surface can be structured that it is nanoporous  and thus provides strong adhesion for organic films. The technique is applicable to many different inorganic surfaces including hard ones as TiO2, and at the same step also drugs can be inserted. This then leads to inorganic surfaces containing biologically active molecules that can be designed to control the interaction with adjacent cells. Examples on this to be presented are antibacterial coatings and surfaces to stimulate the growth of osteoblasts by controlled release of growth factors.

Brief introduction of speaker:

Prof. Helmuth Möhwald is a physicist and physicochemist and received his diploma in physics (1971) and his PhD (1974) from the University Göttingen. He spent nearly five years in industry at IBM San Jose (1974/75) and Dornier-Systems (1975-81), in between getting a habilitation at the University Ulm under the supervision of Prof. Sackmann (1975-78). He was professor for physics (TU Munich, 1981-1987) and for physical chemistry (University of Mainz 1987-93). Since 1993 Möhwald is Director and Scientific Member at the Max Planck Institute of Colloids and Interfaces heading the department ‘‘Interfaces’’. He is also honorary professor at the University Potsdam, the Chinese Academy of Science and Harbin Institute of Technology, guest professor at Fudan and Zheijang University.

According to WoS (Core) ( january 2015): >970 publications, h=101,> 43.000 citations*