Well-Defined Polymeric Double Helices with Solvent-TriggeredDestruction from Amphiphilic Hairy-Like Nanoparticles.

Fabricationof nanostructures with great complexity and regularity is a topicof intense current interest because of their importance both in fundamentaltheories and applications. Here we report an interesting finding ofthe formation of ordered polymeric double helices with precise structuresand high stability. These uniform double helices are hierarchicallyself-assembling results of undulated multicompartment cylinders whichformed from primary amphiphilic mixed-shell nanoparticles. Diblockcopolymers of P2VN-b-PAA (poly(vinylnaphthalene)-block-poly(acrylic acid) and PEO-b-PAA(poly(ethylene oxide)-block-poly(acrylic acid)) werenoncovalently/electrostatically cross-linked into amphiphilic PEO/P2VN-shellednanoparticles by 1,6-hexyldiamine in a common solvent DMF. When thecommon solvent changed into selective ones (water), undulated cylinderswere facilely obtained due to their hydrophobic interparticles interactions.After a certain time aging, these undulated cylinders self-organizedinto finally thermodynamic-stable double helices with complex butregular superstructures. The conditions and processes of assemblingwere carefully examined through extensive experiments. [ABSTRACT FROM AUTHOR]