0000000000165587
AUTHOR
Rodney D. Priestley
Directed Assembly of Soft Colloids through Rapid Solvent Exchange
We studied the directed assembly of soft nanoparticles through rapid micromixing of polymers in solution with a nonsolvent. Both experiments and computer simulations were performed to elucidate the underlying physics and to investigate the role of various process parameters. In particular, we discovered that no external stabilizing agents or charged end groups are required to keep the colloids separated from each other when water is used as the nonsolvent. Furthermore, the size of the nanoparticles can be reliably tuned through the mixing rate and the ratio between polymer solution and nonsolvent. Our results demonstrate that this mechanism is highly promising for the mass fabrication of un…
Rapid Production of Internally Structured Colloids by Flash Nanoprecipitation of Block Copolymer Blends.
Colloids with internally structured geometries have shown great promise in applications ranging from biosensors to optics to drug delivery, where the internal particle structure is paramount to performance. The growing demand for such nanomaterials necessitates the development of a scalable processing platform for their production. Flash nanoprecipitation (FNP), a rapid and inherently scalable colloid precipitation technology, is used to prepare internally structured colloids from blends of block copolymers and homopolymers. As revealed by a combination of experiments and simulations, colloids prepared from different molecular weight diblock copolymers adopt either an ordered lamellar morph…
In Silico Design Enables the Rapid Production of Surface-Active Colloidal Amphiphiles
A new technology platform built on the integration of theory and experiments to enable the design of Janus colloids with precision control of surface anisotropy and amphiphilicity could lead to a disruptive transformation in the next generation of surfactants, photonic or phononic materials, and coatings. Here, we exploit molecular dynamics (MD) simulations to guide the rational design of amphiphilic polymer Janus colloids by Flash NanoPrecipitation (FNP), a method capable of the production of colloids with complex structure without the compromise of reduced scalability. Aided by in silico design, we show in experiments that amphiphilic Janus colloids can be produced using a unique blend of…
On the Stability of Polymeric Nanoparticles Fabricated through Rapid Solvent Mixing.
We study the stability of polymeric nanoparticles fabricated through the rapid mixing of polymers in a good solvent with a poor solvent that is miscible with the good solvent. In previous experiments where water was used as the poor solvent, a negative surface charge was measured on the precipitated nanoparticles, which led to the long-time stability of the dispersion. It was argued that these charges originate presumably from either water or hydroxide adsorption at the hydrophobic nanoparticle surface or from impurities in the feed streams that preferentially adsorb on the precipitated nanoparticles. To elucidate the origin of this stabilization mechanism, we performed experiments wherein …