Achieving white light emission using melamine–formaldehyde microcapsules containing three fluorescence color-emitting conjugated polymers

Fluorescent conjugated polymers (CPs) emitting blue, green, and red were polymerized via the Suzuki coupling reaction. Their emissive monomer units were linked to a fluorene unit in the backbone and thus could be excited at the same wavelength to fluoresce their own emission colors. The resultant polymers were dissolved in dioctyl phthalate, which was embedded in melamine–formaldehyde microcapsules (MFMs). The CP-embedded MFMs maintained the red, green, and blue emission colors of the CPs. The three fluorescent MFMs were mixed in suitable amounts to fabricate white light-emitting MFMs under single-wavelength excitation. The microcapsule embedment could effectively avoid the unnecessary energy transfer from short- to long-wavelength emission, which is a crucial obstacle for white emission when using mixed colors. Thus, white light emission was successfully obtained using spatially separated MFMs in aqueous solution.

Graphical Abstract

White light emission was performed using spatially separated RGB conjugated polymers embedded in melamine-formaldehyde microcapsules.