RESUMO
The past few years witnessed the rapid development of bottom-up synthesis strategies for preparing various nanostructures (i.e., nanoparticles, nanorods, nanowires, etc.) with distinct morphology-dependent properties. In this study, we reported a facile and efficient synthesis method for preparing anatase titanium dioxide (TiO2) nanorings based on multiarm, starlike amphiphilic polystyrene-b-poly(acrylic acid) (PS-b-PAA) diblock copolymers as nanoreactors which were prepared via a sequential atom-transfer radical polymerization (ATRP) technique followed by the conversion of polystyrene-b-poly(tert-butyl acrylate) (PS-b-PtBA) to PS-b-PAA. The outer PAA block of nanoreactors possessed carboxylic acid groups which could coordinate with a titanium precursor followed by high-temperature calcination to form crystalline TiO2 nanorings. The living nature of ATRP enabled the precise preparation of starlike diblock copolymer nanoreactors with a controlled length of each block (i.e., PtBA and PS), thereby tailoring the inner diameter and wall thickness of the resulting TiO2 nanorings, which were inaccessible to conventional routes.
RESUMO
Size and surface functionality are critically important for organic-inorganic hybrid semiconductive nanocomposites in terms of stable photoelectrochemical properties and superior device performance. The ability of reversible deactivation radical polymerization to control the chain length and dispersity of polymers is herein extended to the tailor-made synthesis of nanocomposites with tunable size, distribution, and surface coating. This is exemplified by the fabrication of cadmium selenide (CdSe) quantum dots (QDs) with uniform sizes from 2 to 10 nm that are intimately coated with poly(3-hexylthiophene) (i.e., CdSe@P3HT).
