Stereocomplex Nanocomposite Switch Based on Dynamic Helical Polymer-Gold and Silver Nanoparticle Hybrid Materials

High Resolution Image Download MS PowerPoint Slide Controlled ON/OFF stereocomplexation of dynamic helical polymer-metal nanoparticle nanocomposites─poly(phenylacetylene)-MNP nanocomposites (M = Au or Ag)─is presented. These novel hybrid materials can be found either as well-dispersed metal nanoparticles (MNPs) (stereocomplex OFF) or as fiber-like aggregates (stereocomplex ON) with the metal nanoparticles distributed along the material. A stereocomplex-MNP nanocomposite is formed by the interaction of two complementary and enantiomeric helical polymer-MNP nanocomposites [Poly-( R )- 1 -M 1 NPs/poly( S )- 1 -M 2 NPs (M 1 = M 2 or M 1 ≠ M 2; M = Au, Ag)]. Interestingly, by using dynamic helical polymers, i.e., poly(phenylacetylene)s (PPAs), as coating agents of the metal nanoparticles, it is possible to tune the secondary structure of the polymer─elongation and/or compression─a fact that can trigger the formation/disruption of the stereocomplex. Moreover, the stereocomplexation of these nanocomposites can be controlled in a reversible way (ON/OFF) by playing with the supramolecular interactions that keep the two enantiomeric and complementary helices together, such as hydrogen bonds.