Vasileios Koutsos

Institute for Materials and Processes, School of Engineering, The University of Edinburgh, Sanderson Building, The King's Buildings, Mayfield Road, Edinburgh EH9 3JL, United Kingdom

Polymers and nanoparticles at surfaces and interfaces

Abstract

 

Polymers and nanoparticles can self-assemble into a variety of nanostructures and nanopatterns on surfaces offering alternative ways of facile and inexpensive nanofabrication routes. Such fabrication methodologies have great potential for the efficient assembly of nanoscale structures for many applications ranging from micro/nanoelectronics and chemical sensor technology to biomedical implants and targeted drug/gene delivery. However, there are plenty of unsolved problems in our fundamental understanding of the behaviour of soft materials and complex fluids in confined spaces. The prediction and determination of materials properties at the nanoscale is not a trivial task and unexpected deviations from bulk behaviour are not uncommon. In this talk, I will present investigations of nanostructures formed on surfaces by the self-assembly of homopolymers, block copolymers, graft copolymers, binary polymer blends, and nanoparticles. The AFM images show clearly the formation of soft nanostructures which are the direct consequence of confinement and/or interfacial interactions with the solid substrate. The overall behaviour at surfaces is different to what is expected from bulk behaviour. The phenomena studied include increased elastic modulus of polymer nanodroplets due to surface ‘pinning’, lamellae formation parallel to the substrate for asymmetric diblock copolymers, quantum dot nanoparticle-induced effects on the phase separation of conjugated polymer thin films and colloidal crystallisation in ‘coffee-stain’ ring deposits. Furthermore, examples of the use of block copolymers in carbon-nanotube polymer composites will be shown. Mechanical measurements and scanning electron microscopy observation revealed that the block copolymers significantly improved both the carbon nanotube dispersion in the polymer matrix and the interfacial bonding/load transfer.


Date: 21/5/2014
Time:12:00 (coffee & cookies will be served at 11:45)
Place:FORTH Seminar Room 1