Template-Directed Mild Synthesis of Anatase Hybrid Nanotubes within Cylindrical Core-Shell-Corona Polymer Brushes

We demonstrate the synthesis of uniform one-dimensional (1D) titania hybrid nanotubes using core-shell-corona cylindrical polymer brushes (CPBs) as soft templates. The CPBs consist of a polymethacrylate backbone with densely grafted poly(epsilon-caprolactone) (PCL) as the core, poly(2-(dimethlamino)ethyl methacrylate) (PDMAEMA) as the cationic shell, and poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) as the corona. The weak polyelectrolyte shell complexed an oppositely charged titania precursor, namely titanium(IV) bis(ammonium lactate) dihydroxide (TALH), and then acted as a nanoreactor for the hydrolysis and condensation of TALH, resulting in crystalline TiO2. The POEGMA shell provides solubility in aqueous and organic solvents. The hybrid titania nanotubes containing anatase nanoparticles were characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), and scanning electrion microscopy (SEM). The phase purity of the crystalline nanostructures was verified by powder X-ray diffractometry (PXRD).