Polymer Carbon Dots-A Highlight Reviewing Their Unique Structure, Bright Emission and Probable Photoluminescence Mechanism

In recent years, a novel fluorescent material, carbon dots (CDs), is becoming a hot topic. Recent research works found that some types of CDs with high quantum yield are mainly composed of polymer structures or polymer/carbon hybrid structures rather than the pure carbon/graphite structure. These types of CDs, named as polymer carbon dots (PCDs) here, are drawing growing interests due to the designed hybrid structure and functional integration. Typically, PCDs are nano-sized particles possessing abundant polymer structures with low carbonization degree, prepared from the monomers or non-conjugated polymers by condensation, crosslinking, assembling, or slightly carbonization processes. In this highlight, we bring up the new concept of PCDs and discuss the relationships among non-conjugated polymer, PCDs and CDs, demonstrating that the possible fluorescence mechanism of PCDs is inferred as crosslink enhanced emission effect. Furthermore, the structure, properties, and synthetic methods of the reported typical PCDs were summarized and prospected. (C) 2016 Wiley Periodicals, Inc.