Synthesis of Amphiphilic Superparamagnetic Ferrite/Block Copolymer Hollow Submicrospheres

Abstract

Self-assembly can be a powerful, but simple, synthetic method for the fabrication and surface modification of nanometer- to micrometer-sized hollow spheres. Here we report a facile route for preparation of submicrometer ferrite hollow spheres which are amphiphilic and superparamagnetic. This unique approach involves the formation of ferrite nanocrystals and the simultaneous self-assembly of nanocrystals and block copolymer PEO-PPO-PEO into hollow spheres. Furthermore, this approach is general for the preparation of a series of ferrite hollow spheres, including Fe3O4, Co1-xFe2+xO4, and Mn1-xFe2+xO4. Unlike conventional hollow spheres, which are either hydrophobic or hydrophilic, the products we obtained exhibit excellent dispersibility in both polar and nonpolar solvents.

Controlled Synthesis, Growth Mechanism, and Properties of Monodisperse CdS Colloidal Spheres

“…The PVP molecules play an important role in preventing the spheres from agglomerating as many polymer molecules do in the formation of other spherical species. [12,33] However, when we used non-PVP surfactants, such as poly(ethylene glycol), poly(vinyl alcohol), poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) for the preparation of CSCS, no spherical structures were obtained under the same reaction conditions. This observation suggests that the PVP molecules may be unique for the formation of the CSCS in the current reaction system.…”

Hollow Micro‐/Nanostructures: Synthesis and Applications

“…Li et al reported a one-step solvothermal route to prepare superparamagnetic firrite/polymer hybrid hollow spheres. [244] This synthesis involves formation of ferrite nanoparticles and simultaneous self-assembly of nanoparticles and PEO-PPO-PEO into hollow spheres. Polymer hollow nanospheres can also be derived from the self-assembled core/shell polymer micelles.…”

Supramolecular nano-assemblies with tailorable surfaces: recyclable hard templates for engineering hollow nanocatalysts

“…Although great efforts have been made towards the development of template-free routes for the preparation of hollow structures [13][14][15], template-directed synthetSchool of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China * Corresponding authors (email: xinhaoli@sjtu.edu.cn (Li XH); chemcj@sjtu.edu.cn (Chen JS)) ic methods have been established as one of the most effective and controllable methods for synthesizing hollow structures [16]. The most commonly used templates can broadly be divided into two categories: hard templates and soft templates.…”

“…The void space can also act as a catalyst container for embedded fine metal nanoparticles to extend their life-time [9,10]. Moreover, the thin shell of hollow micro-and nanoscale structures can facilitate charge transfer to surface active sites [11], which implies that they have great potential as highly efficient photocatalysts for water splitting and artificial photosynthesis [12].Although great efforts have been made towards the development of template-free routes for the preparation of hollow structures [13][14][15], template-directed synthetSchool of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China * Corresponding authors (email: xinhaoli@sjtu.edu.cn (Li XH); chemcj@sjtu.edu.cn (Chen JS)) ic methods have been established as one of the most effective and controllable methods for synthesizing hollow structures [16]. The most commonly used templates can broadly be divided into two categories: hard templates and soft templates.…”