Micro- and nanophase separations in hierarchical self-assembly of strongly amphiphilic block copolymer-based ionic supramoleculesElectronic supplementary information (ESI) available. See DOI: 10.1039/c2sm27113c

By a selective complexation between different alkyltrimethylammonium amphiphiles (C8, C12 and C16) and three different diblock copolymer systems of poly(styrene)- b -poly(methacrylic acid) at various grafting densities X ( X = number of alkyl chains per acidic group of the poly(methacrylic acid) PMAA block), a class of ionic supramolecules are successfully synthesized whose molecular architecture consists of a poly(styrene) PS block (Linear block) covalently connected to a strongly amphiphilic comb-like block (AmphComb block), i.e. Linear- b -AmphComb. In the melt state, these ionic supramolecules can show simultaneous microphase (between Linear and AmphComb blocks) and nanophase (within the AmphComb blocks) separations. This leads to the formation of various structure-in-structure two-scale hierarchical self-assemblies, including S-in-S LL , S-in-S BCC , S-in-C, S-in-L and C-in-L, where S, S LL , S BCC , C and L stand for spherical, spherical in liquid-like state, spherical in body-centered-cubic arrangement, cylindrical and lamellar, respectively. Synchrotron small angle X-ray scattering (SAXS) and crossed polarizers, together with SAXS modelling analysis, were used for a detailed structural study of the samples. The morphology of the microphase separated state was mapped out on 'master' microdomain morphology diagrams as a function of the volume fraction of the AmphComb blocks ( Φ AmphComb ) and the compositional window of each microdomain morphology was determined. It was observed that, (i) within samples based on the same parent diblock copolymer system, the occurrence of a specific microdomain morphology is only dependent on the value of Φ AmphComb , regardless of the grafting density X and the length of the alkyl side-chains, and (ii) microdomain morphological boundaries occur at Φ AmphComb values of ∼0.20 (S LL /C and S BCC /C) and ∼0.28 (C/L). Finally, the specific influences of the strongly amphiphilic nature of the AmphComb blocks on the observed morphological and hierarchical behaviours of our system are discussed. For reference, stoichiometric strongly amphiphilic comb-like (AmphComb) ionic supramolecules, based on complexation between a homopolymer of PMAA and the various alkyltrimethylammonium amphiphiles, were prepared, which nanophase separated into S (C8) or C (C12 and C16) domains. A new class of block copolymer-based ionic supramolecules that are composed of a linear polymeric block (Linear block) covalently connected to a strongly amph