Application of X-ray and Neutron Scattering Techniques for the Characterization of Polymer/Nanoparticle Composites

摘要

We demonstrate the versatility of various X-ray and neutron scattering techniques to investigate the solution/bulk/film morphologies of multi-component block copolymer/nanoparticle composites. The morphologies of the block copolymer phase in block copolymer/nanoparticle complexes in a selective solvent were studied using small angle neutron scattering (SANS) as the contribution of inorganic nanoparticles to SANS signal is quite weak when compared to the polymer phase in a deuterated solvent. Solvents used for controlling the self-assembly of polymer nanocomposites have strong influence on the order-disorder and order-order transition temperatures. We observe that the morphologies of the neat and nanoparticle-containing polymer solutions strongly depend on the concentration of nanoparticles and temperature. Comparison of the phase diagrams of the neat and nanoparticle-containing polymer solutions as a function of temperature clearly shows dramatic shifts in the order-disorder and order-order transition temperatures. This dramatic effect can be understood by a model wherein the added nanoparticles that sequester in the preferred domains increase the interfacial curvature, leading to the changes in the morphology of the composite.