Self-organization of double-C60 end-capped poly(ethylene oxide) in chloronaphthalene and benzene solvent mixtures

Hydrogen-bonding-induced complexation of polydimethylsiloxane-graft-poly(ethylene oxide) and poly(acrylic acid)-block-polyacrylonitrile micelles in water

Polydimethylsiloxane-graft-poly(ethylene oxide) (PDMS-g-PEO) copolymers form micelles in water with PDMS as the core and PEO as the corona. The introduction of poly(acrylic acid)-block-polyacrylonitrile (PAA-b-PAN) block copolymers in water leads to the formation of micellar complexes due to the hydrogen bonding between carboxyl groups and ether oxygens among the PAA and PEO chains in the corona of the micelles. The effects of pH, molar ratios (r) of PAA/PEO, and the standing time on the directly mixing these two micelles in water have been investigated using laser light scattering (LLS) and transmission electron microscopy (TEM). Our results showed that the complexation between PAA and PEO in the corona was greatly enhanced at a pH below 3.5. For a fixed pH value, the interactions between these two micelles in water were governed by the value of r. At r < ∼0.6, mixing the two micelles in water resulted in a large floccule because the smaller PAA-b-PAN micelles act as physical cross-links, which are absorbed onto one PDMS-g-PEO micelle and simultaneously bonded to PEO chains on the other micelles, forming bridges and causing flocculation. At ∼0.6 < r < ∼1.2, the mixing led to stable micellar complexes with a layer of PAA-b-PAN micelles absorbed onto the initial PDMS-g-PEO micelles. At r > ∼1.2, the resultant micellar complexes first remained stable, but they precipitated from solution after a long time standing.

Amphiphilic poly(p-phenylene)-driven multiscale assembly of fullerenes to nanowhiskers

Molecular level alignment of components and optimum morphology of hybrid materials are of great interest in many applications. Morphology control has been extensively used as a direct tool in the evaluation of interactions and assemblies of components in thin films. It is believed that preparation method and composition are powerful tools to direct the morphology, particularly in self-assembled systems such as fullerene-based hybrid materials. The present report outlines a synergistic self-assembly of fullerenes (C(60)) and functionalized poly (p-phenylene) (PPP) to develop nanofibers with high aspect ratios. Nanostructured PPP-C(60) hybrids were prepared by direct casting of the dilute solution on solid substrates and on water under ambient conditions. The formation of whiskers with high aspect ratio and investigation of interesting photophysical properties are discussed. An amphiphilic PPP was used as a template for preparing nanohybrids of C(60) at ambient temperature and conditions.