Using Neutron Reflectometry to Investigate Interactions across Polymer Thin Films
Uhrig, Jamie Messman, Jimmy Mays, and Phil Britt, CNMS
J. F. Ankner, X. Tao, C. Halbert, Spallation Neutron Source, ORNL
S. M. Kilbey, II, Clemson University, Clemson, SC, and CNMS Visiting Scientist
Results emerging from studies of isotopically-substituted polystyrene nanolayers in contact with dilute polystyrene solutions are providing experimental verification of theories that predict compaction of the layer due to repulsive osmotic interactions, and also suggest absorption of low molecular weight species. The resources and tools available at CNMS and coming online at SNS provide unprecedented opportunities for understanding the links between the design, assembly, structure and dynamics of “soft” (polymeric) materials, engendering “bottom-up” strategies for the rational design of polymer thin films for numerous technologies.
work was carried out within Partner User Project CNMS2003-041, including
contributions from researchers sponsored by the BES Division
of Scientific User facilities. Partner users were supported by
the BES Division of Chemical Sciences, Geosciences and Biosciences
Reflectivity measurements of surface-tethered polymer nanolayers (left, cartoon in middle) reveal the structure (right) of the interfacial layer and structural rearrangement upon exposure to and interaction with ultra-dilute solutions of polymers. Experiments were carried out on the SNS Liquids Reflectometer at a beam power of 30 kW and source frequency of 15 Hz.