Molecular Variables in the Self-Assembly of Supramolecular Nanostructures

Abstract

Supramolecular structures have the potential to provide macromolecular behavior using relatively low molar mass building blocks. We present here data on the self-assembly of triblock rodcoil molecules which contain a rigid biphenyl ester segment covalently linked to structurally diverse oligomeric segments. These molecules form supramolecular aggregates with molar masses in the range 105−106 Da, and our experiments probe how supramolecular structure can be manipulated by varying the volume fraction of the coillike flexible segments with respect to that of rod segments. The oligostyrene−oligoisoprene diblock coils were synthesized via anionic polymerization and varied in average length from (6sty, 6iso) to (30sty, 30iso). Small-angle X-ray scattering scans revealed layer spacings corresponding to monolayers that increase in size as the coil's molar mass increases. We observed that an increase in coil volume fraction reduces the thermal stability of the supramolecular structure, but a corresponding increase in rod segment length can counteract this effect. Finally the self-organized nanostructures seem to pack into a superlattice based on evidence obtained by X-ray scattering and transmission electron microscopy.

Functional Liquid‐Crystalline Assemblies: Self‐Organized Soft Materials

“…Recently, new-materials design, using microphase-segregation of block polymers [48,168,169] and small molecules [10,170,171] has attracted much attention because elaborate three-dimensional (3D) nanostructures with dimensions of between tens and hundreds of nanometers are easily obtained by selforganization. The morphology of the segregation at the nanometer scale [9] is relevant to the micro-segregation behavior of block polymers.…”

Funktionelle flüssigkristalline Aggregate: selbstorganisierte weiche Materialien

“…Kürzlich rief das Design neuer Materialien mithilfe von Mikrophasentrennung bei Blockcopolymeren [48,168,169] und kleinen Molekülen [10,170,171] großes Interesse hervor, da so durch Selbstorganisation leicht komplexe dreidimensionale Nanostrukturen mit Größen zwischen einigen 10 und mehreren 100 nm aufgebaut werden können. Die Strukturen, die durch Phasentrennung auf der Nanometerebene entstehen, sind bedeutsam für die Mikrophasentrennung von Blockcopolymeren.…”

Synthesis and Characterization of Helix‐Coil Diblock Copolymers with Controlled Supramolecular Architectures in Aqueous Solution

“…[3][4][5] Due to the combined results of the orientation of the rod block and the microphase separation of the two incompatible blocks, rod-coil block copolymers exhibit distinct self-assembling behaviors and morphologies compared to their coil-coil counterparts. [6][7][8][9][10] The incorporation of helical chains as the rigid-rod component in rod-coil copolymers represents a unique approach to creating novel supramolecular architectures. [11][12][13][14][15][16] In the studies of polystyrene-block-poly(isocyanodipeptide) in aqueous solution, the chirality of the macromolecules results in the formation of superstructures that have a helical sense bias opposite to that of the constituent block copolymers.…”