Past Seminars Seminários Já Decorridos 2006

Harnessing light to create hierarchically ordered, defect-free polymeric materials

By: Rui Travasso
From: Center of Theoretical and Computational Physics, University of Lisbon
At: Complexo Interdisciplinar, Anfiteatro
[2006-04-26] 11:30

Computer simulations reveal how photoinduced chemical reactions in polymeric mixtures can be exploited to create long-range order in materials with features that range from the submicron to the nanoscale. The process is initiated by shining a spatially uniform light on a photosensitive AB binary blend, which thereby undergoes both a reversible chemical reaction and a phase separation. When a well-collimated, higher intensity light is rastered over the sample, the system forms defect-free, spatially periodic structures. If a nonreactive component C is added to the system, this component localizes in regions that are irradiated with a higher intensity light, and one can effectively