Thursday, November 12, 2015: 10:45 AM
Canyon B (Hilton Salt Lake City Center)
We present rapid, room temperature synthesis of PEG-stabilized gold nanoparticles using Flash NanoPrecipitation (FNP), a polymer directed self-assembly method. During FNP, an aqueous solution of gold chloride is rapidly mixed with an amphiphilic PEG-based block copolymer dissolved in an organic solvent with a reducing agent, tannic acid (TA). Upon mixing, gold chloride is reduced by TA and encapsulated by the self-assembling PEG-based block copolymer. Simultaneous gold reduction and polymer self-assembly facilitated by the rapid mixing prevent secondary nucleation and Ostwald ripening. The result is kinetically controlled growth and size focusing of encapsulated gold nanoparticles of uniform size (standard deviation <15%). The size of the resulting gold nanoparticles and hydrodynamic diameter of the nanoparticle construct can be tuned by varying the pH. We anticipate FNP will be a versatile platform for single-step, room temperature processing PEG-stabilized gold nanoparticles with tunable surface chemistry. Continuous processing may also be possible.