Analysis of SANS Patterns from 1D Symmetrically Confined Polymers

Understanding how polymer chain conformations are altered under nanoconfinement is critical for understanding polymer behavior in applications ranging from nanoscale lithography to polymer nanocomposites. Previous work that measured polymer conformations under 1D confinement has been limited to using “open face” thin films, where at least one confining surface is free. In these samples, changes in the polymer conformations perpendicular to the confining surfaces have proven difficult to measure. Our study uses a new and unique sample geometry, consisting of long, narrow, and deep polymer filled channels that rigidly confine the polymer on both sides. This geometry should allow SANS to simultaneously probe chain conformation parallel and perpendicular to the confining surfaces. The resulting anisotropic SANS patterns from empty templates are fit using a dynamical theory based on the Bloch wave expansion of the neutron wave function to account for the complex nature of the template. Here we present our initial results developing the fitting theory and extracting polymer R_g in the confined and unconfined dimensions.