Synthesis and self-assembly of side-chain azocomplex for preparation of solid and hollow nanosphere

A new strategy based on ionic self-assembly technology was provided for design of solid and hollow nanospheres. Solid azocomplex nanospheres were constructed by ionic self-assembly of statistical ionomer and metanil yellow. The structure of azocomplex and self-assembly behaviors were examined by a variety of techniques including ¹H-NMR, ¹³C-NMR, DSC, FTIR, UV–vis, TEM, and elemental analysis. The azocomplex was subjected to solvent-induced self-assembly to construct a variety of morphologies. Solid polymeric nanospheres with the sizes of 50~100 nm in diameter were formed in aqueous solution. High-resolution transmission electron microscopes and X-ray energy dispersion spectrometer were used to study the morphology and composition of the solid nanospheres. The spherical and ordered structure was destroyed in DMF, and converted into membrane structure. Polymeric hollow nanospheres with azobenzene chromophores were formed in DMF/H₂O mixed solvent, with 62.5% H₂O in mass. The size of these hollow nanospheres was 50~120 nm in diameter.