Rheology pathway to macroscale ordered nanostructures of polymeric nanotemplates: Nanopores, nanosheets and nanofibers

The creation of nanotemplates under dynamic shear flow conditions is described. The structures used are based on the self-organization of comb-coil-like diblock copolymer systems with two intrinsic length scales, resulting from combining diblock copolymers with hydrogen-bonding amphiphiles. Rheological data of polymeric supramolecular order formation are studied under oscillating shear flow conditions and it was observed that the order of the polymeric nanodomains can be extended to macroscopic distances. It is proposed that the key success factor to obtain highly ordered samples is to perform the orientation process using appropriate rheological conditions (temperature, frequency and strain) selected such that the ratio of the elastic component a to the viscous component G is larger than 1. This observation was used to select the rheological parameters for the three different samples investigated, where three different types of nanotemplates are observed after extracting the hydrogen-bonding amphiphile; nanosheets, hollow cylinders and nanofibres. SAXS is primarily used to inspect the resulting structures. Additionally, AFM and TEM were utilized to image the morphologies and to further act as visual proof for the efficiency of the rheological orientation process.