Emission-Color Control in Polymer Films by Memorized Fluorescence Solvatochromism in a New Class of Totally Organic Fluorescent Nanogel Particles.

In this work, a new class of totally organic fluorescent nanogel particles and their exceptionally specific behaviors based on their unique structures are introduced, which draws a sharp line from conventional fluorophore-doped and fluorophore-branched-type particles. The nanogel particles, the diameter of which could be controlled by adjusting reaction conditions, such as the solvent system, were spontaneously fabricated with a spherical shape by direct polymerization of non-heterocyclic aromatic compounds, such as 2,6-dihydroxyanthracene, 2,6-dihydroxynaphthalene, and 9,9-bis(4-hydroxyphenyl)fluorene with triazinane as the cross-linker. A fluorophoric moiety formed from a polymer main chain was realized in the particle, and consequently, the resultant content of the fluorophoric moiety was around 70-80 wt % per particle. The uniqueness and versatility of the particles can be emphasized by their good compatibility with various solvents due to their amphiphilic and ampholytic swelling properties, but also by their remarkable fluorescent solvatochromism in the dispersion state. Furthermore, these behaviors were preserved even in their polymer composite system. This study also demonstrates that various fluorescent polymer films can be fabricated with emission color control due to memorization of the solvatochromism phenomenon of the dispersed fluorescent nanoparticles.

Amphiphilic spherical nanoparticles with a nitrogen-enriched carbon-like surface by using ß-lactoglobulin as a template.

We demonstrate a versatile and facile method for fabrication of a new class of amphiphilic spherical nanoparticles having a nitrogen-enriched carbonised surface and precisely-controlled morphology. They are prepared by one-pot polymerization with ß-lactoglobulin aggregates as a template with tunable size (70-750 nm) and mild heat-treatment to extend the π-conjugated structures.