RESUMO
This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article was retracted at the request of the Editor. The above paper is essentially a duplicate of an original Article in "Size-Controlled Synthesis of Polymer Nanoparticles with Tandem Acoustic Emulsification Followed by Soap-Free Emulsion Polymerization" ACS Macro Lett., 2013, 2 (6), pp 482484, 10.1021/mz4001817.
RESUMO
We have developed a novel synthesis method for size-controlled polymer nanoparticles using soap-free emulsion polymerization. This new synthetic method involves sequential ultrasonic irradiation (20 kHz â 500 kHz â 1.6 MHz â 2.4 MHz) for acoustic emulsification of a water-insoluble monomer such as methylmethacrylate (MMA) in an aqueous medium, followed by emulsion polymerization in the obtained solution without using any surfactants. The sequential ultrasonication (tandem acoustic emulsification) could provide a clear and stable emulsified solution containing monomer droplets with relatively narrow size distribution in the nanometer range. The subsequent polymerization in this solution yielded size-controlled polymer nanoparticles. Furthermore, colloidal crystal films could be easily prepared from the as-polymerized nanoparticle solution using the fluidic-cell method.