Geometrically-structured polymer nanocolloids, including Janus colloids, have been widely studied for their unique self-assembly behavior derived from the anisotropy of their surface domains.  Incorporating inorganic nanoparticles into the colloids adds functionality to these particles that could enable applications such as in biphasic catalysis.  Here, we demonstrate our ability to produce hybrid polymer-inorganic nanocolloids in a one-step process using Flash NanoPrecipitation (FNP).  The FNP process involves rapid mixing of a polymer solution with a poor solvent, inducing polymer precipitation in a confined volume.  In addition to being a scalable process with the ability to generate kilograms of material per day, FNP is a flexible process which allows for simultaneous control over colloid morphology and inorganic nanoparticle location using the same non-capital intensive equipment.  Colloid morphology can be controlled by tuning the interactions between the polymers and the surrounding solvent to produce core-shell, spherical Janus, and snowman Janus polymer colloids.  Inorganic nanoparticle location within the polymer nanocolloid is then determined by the interactions between the nanoparticles and the two polymers, allowing for placement on either domain surface or along the nanocolloid circumference.  We explore several methods of tuning interactions between the polymers, inorganic nanoparticles, and solvent such as adding functionality to the polymers in the feed stream or incorporating a surfactant into the system and suggest that the resulting colloid morphology is determined by a minimization of the particle surface free energy.  The flexibility and continuous nature of the FNP process will enable industrial-scale production of hybrid polymer-inorganic Janus particles.

Controlling morphology and nanoparticle location within hybrid polymer-inorganic Janus particles using flash nanoprecipitation

253rd National Meeting (2017)

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