Water-soluble light-emitting nanoparticles prepared by non-covalent bond self-assembly of a hydroxyl group functionalized oligo(p-phenyleneethynylene) with different water-soluble polymers

Water-soluble light-emitting nanoparticles were prepared from hydroxyl group functionalized oligos(p-phenyleneethynylene) (OHOPE_L) and water-soluble polymers (PEG, PAA, and PG) by non-covalent bond self-assembly. Their structure and opto-electronic properties were investigated through dynamic light scattering (DLS), UV and PL spectroscopy. The optical properties of OHOPE_L-based water-soluble nanoparticles exhibited the same properties as that found in OHOPE_L films, indicating the existence of interchain π-aggregation of OHOPELs in the nanoparticles. OHOPE _L-based nanoparticles prepared from conjugated oligomers show smaller size and lower dispersity than nanoparticles from conjugated polymers, which means that the structures of water-soluble nanoparticles are linked to the conjugated length. Furthermore, the OHOPE_L/PG and OHOPE _L/PAA systems produced smaller particles and lower polydispersity than the OHOPE_L/PEG system, indicating that there may exist influence of the strength of non-covalent bonds on the size and degree of dispersity of the nanoparticles.