Review of Conjugated Polymer Nanoparticles: From Formulation to Applications

Abstract

Conjugated polymers, which exhibit electrical and optical properties owing to the presence of conjugated π bonds along the polymer backbone, are semiconducting materials of utmost interest. However, their immiscibility in water imposes restrictions on their usage; they are typically processed using toxic and environmentally harmful organic solvents. To address these issues, research has focused on converting conjugated polymers into nanoparticle dispersions in water or alcohols. This strategy not only avoids toxic solvent usage but also enhances application utility. In this article, to provide a comprehensive understanding of conjugated polymer nanoparticles, we introduce two principal approaches for classifying nanoparticle formation strategies and their corresponding experimental methods: with respect to the particle formation mechanisms and their preparation methods; we will discuss six such methods. Then, we review three different applications of the conjugated polymer nanoparticles in the fields of electronics, energy, and bioimaging, associating their requirements for attaining superior device performance with the characteristics of each method, and accordingly discuss methodological perspectives for each application.

Red-Fluorescing Paramagnetic Conjugated Polymer Nanoparticles─Triphenyl Methyl Radicals as Monomers in C–C Cross-Coupling Dispersion Polymerization

“…Conjugated polymer nanoparticles (CPNs) can be obtained through polymerization of soluble monomers in a solvent, in which the resulting desired polymer is insoluble. A variety of different preparation methods has been brought forward to control the sizes of the CPNs; − however, only dispersion polymerization − yields particles of sufficiently low dispersity to allow their application in the fields of photonics , and bioimaging. − CPNs have been reported to exhibit high photostability, as well as excellent biocompatibility. − However, to date, no open-shell monomers have been employed in these dispersion polymerizations, and it remains unknown whether the radical nature could survive the reaction conditions of transition-metal-mediated C–C cross-coupling reactions. Incorporation of open-shell monomers into CPNs could open up completely new particle features and render CPNs paramagnetic.…”

Red-Fluorescing Paramagnetic Conjugated Polymer Nanoparticles – Triphenyl Methyl Radicals as Monomers in C-C Cross-Coupling Dispersion Polymerization

“…Conjugated polymer nanoparticles (CPNs) can be obtained through synthesis of a desired conjugated polymer in a solvent, in which the resulting polymer is insoluble in. A variety of different preparation methods has been brought forward to control the sizes of the CPNs; [17][18][19][20][21] however, only dispersion polymerization [22][23][24][25][26][27] yields particles of sufficiently low dispersity to allow their application in the fields of photonics, 28,29 and bioimaging. [30][31][32][33][34] CPNs have been reported to exhibit high photostability, as well as excellent biocompability.…”

Graphene Oxide: Key to Efficient Charge Extraction and Suppression of Polaronic Transport in Hybrids with Poly (3-hexylthiophene) Nanoparticles

“…More recently, self-assembly strategies shaping conjugated polymers into nanofibers or spherical nanoparticles have enjoyed increased interest. 17 − 21 They convey the advantage that the aggregation structure of the polymer chains in these nanoparticles is exclusively pre-established upon their formation in the liquid phase and that the resulting optoelectronic properties are not being altered when processed into films, thus eliminating tedious tasks of controlling film formation parameters. 22 Moreover, the liquid phase approaches, involving either emulsion or reprecipitation technologies, provide a unique opportunity to create stable aqueous dispersions of conjugated polymer nanoparticles and environmentally friendly processing possibilities.…”

“…These nanocrystalline aggregates have a significant influence on the optoelectronic, charge transfer, and charge transport properties of the resulting P3HT films. , Controlling film fabrication parameters, applying thermal post-treatment steps, making use of donor–acceptor blends, and exploiting chemical doping or electrochemical oxidation approaches are widely studied strategies to influence the nanocrystalline aggregate structure and their effects on the exciton and polaron dynamics and to establish favorable interface interactions to achieve enhanced device performance of layered film devices. More recently, self-assembly strategies shaping conjugated polymers into nanofibers or spherical nanoparticles have enjoyed increased interest. − They convey the advantage that the aggregation structure of the polymer chains in these nanoparticles is exclusively pre-established upon their formation in the liquid phase and that the resulting optoelectronic properties are not being altered when processed into films, thus eliminating tedious tasks of controlling film formation parameters . Moreover, the liquid phase approaches, involving either emulsion or reprecipitation technologies, provide a unique opportunity to create stable aqueous dispersions of conjugated polymer nanoparticles and environmentally friendly processing possibilities .…”