Micro-flow assisted synthesis of fluorescent polymer nanoparticles with tuned size and surface properties

Abstract

Numerous different photonics and biomedical applications depend on the fluorescent polymer micro- and nanoparticles. Besides optical or spectroscopic properties, the performance of the polymer nanoparticles is determined by their size, size distribution, and surface charge. Moreover, in order to realize a very uniform performance, the functional polymer nanoparticles should be of high homogeneity and demand for the preparation in a minimum number of synthesis steps. Here, we present a microfluidic-assisted synthesis of different types of reproducible fluorescent polymer nanoparticles with tuned size (40 nm up to 600 nm) and surface charge (ζ potential=-52 mV up to +45 mV). Four different preparation strategies were introduced for fluorophore-functionalized nanoparticles: (a) noncovalent binding of fluorophores with high loading, (b) covalent linking of fluorophores with enhanced stability, (c) surface-anchored fluorophores by hydrophobic interactions for triple function at the same time, and (d) surface immobilization of biomolecules and fluorophore by ionic as well as secondary interactions. In this way, four different classes of nanoparticles suited for different applications were prepared with a spherical shape as a model system. Moreover, the principle has been extended to the different types of nonspherical and composite polymer nanoparticles.

The Role of Sodium Lauryl Sulfate on the Film Properties of Styrene-Butyl Acrylate-Acrylic Acid Copolymer Latex

“…According to DLS measurements, the particle size increased from 75.25 to 118.30 nm with 0.9 % SLS addition, and decreased to 75.18 nm with further increase of SLS concentration to 3.0%. It is known that the latex particles are formed by homogeneous nucleation mechanism at SLS concentration below critic micelle concentration [31]. According to this mechanism, SLS retained on monomer droplets can leave the droplet surface and then adsorb on the growing particle surface.…”

Hierarchical Assemblies of Polymer Particles through Tailored Interfaces and Controllable Interfacial Interactions

“…Second, the flow arrangement is highly promising for assembling nanoparticles of opposite surface charge in a highly uniform manner without irregular distribution. Here flow assembling between anionic flower‐shaped polymer nanoparticles (zeta potential 16 mV) [ 86 ] and cationic spherical polymer nanoparticles (zeta potential +23 mV) [ 99 ] are performed in the flow setup as shown in Figure A. In a simple microflow setup (top left of Figure 4A), both cationic and anionic nanoparticles were pumped through nearby two inlets and generated an integrated solution mixture that is flowing through the outlet to the knot mixture microchannel which is immersed in the water bath.…”

“…For instance, because of the strong binding affinity, poly‐L‐lysine and poly‐L‐glutamic acid link each other with the desired number of layers on the surface. [ 99,131 ] On the other hand, a simple, versatile, and efficient layer‐by‐layer functionalization can be achieved by oppositely charged polyelectrolytes. [ 127,132–134 ] Multi‐layered polyelectrolytes create soft and swellable interfaces that finally leads to a strong interaction with oppositely charged nanoparticles to form particles‐particles nanoassemblies.…”

Interfacial‐Active Polymer Nanoparticles, Their Assemblies, and SERS Application

“…Specifically for many of the nanotechnological applications, polymer based nanoassemblies are of particular interest due to their novel as well as coupled properties . The swelling of polymer particles allows encapsulating as well as controlled release of therapeutic agents at desired sites for biomedical applications .…”