Compartmentalization of Gold Nanocrystals in Polymer Microparticles using Electrohydrodynamic Co‐Jetting

Abstract

Polymer particles with micro- and nanoscale anisotropy have received increasing interest for their ability to simultaneously present different physical- and chemical properties. In this communication, we demonstrate that gold nanocrystals (NCs) can be selectively incorporated into one compartment of anisotropic polymer particles. Stable bicompartmental particles were prepared via electrohydrodynamic co-jetting of aqueous nanoparticle suspensions followed by thermal cross-linking. Bicompartmental particle populations with different NC densities were obtained by varying the NC concentration in the jetting suspension. While NC-loaded polymer particles showed different optical properties depending on the NC density, they still maintained discrete interfaces between two compartments. Moreover, the fraction of the bicompartmental particles was higher than 98% based on flow cytometry. This study delineates a new approach for preparation of inorganic/organic composite particles with precisely engineered, anisotropic nanoparticle distributions and may contribute to further developments in emerging scientific areas, such as smart materials or particle-based diagnostics.

Recent advances with anisotropic particles

“…EHD co-jetting is also based on the laminar flow of two polymeric solutions. Lahann and coworkers have extensively investigated this system [86][87][88][89][90][91][92][93][94], and have prepared bi- [86], tri- [87] and even multicompartmental [91,92] particles and cylinders. The biphasic particles can be induced by the EHD co-jetting of parallel polymer solutions.…”

Compartmentalized Photoreactions within Compositionally Anisotropic Janus Microstructures

“…[14] Beyond polymers, we have reported that inorganic nanomaterials can be selectively incorporated into one side of bicompartmental particles. [18] We now report on spatially controlled photoreactions within anisotropically structured colloids and microfibers. This approach allows for fabrication of biphasic particles and fibers with different mechanical properties in each compartment, as well as selective removal of sacrificial compartments.…”

Fabrication and characterization of anisotropic nanofiber scaffolds for advanced drug delivery systems

“…6 Various original engineering approaches to synthesize anisotropic micro-or nanoarchitectures in the form of various geometries have been explored: electrohydrodynamic (EHD) cojetting, 7 microfluidics, 8 differential solvent evaporation, flow focusing lithography, 9 spinning disks, selective deposition, 10 partial modification by masking, Pickering emulsion, 11 and self-assembly. 12 Of the various methodologies for preparing anisotropic structures, EHD cojetting is specifically interesting as it allows for equilibrated laminar flow of multiple polymer solutions to be ejected from the vertex of a multiphasic Taylor cone. The created thin-jet stream due to charge-charge repulsion results in the formation of multicompartmental architectures.…”