Determination of Critical Micelle Concentration (CMC) of Surfactants Using Environmentally Sensitive Carbonized Polymer Dots

Critical micelle concentration (CMC) is one of the essential parameters for surfactants. To accurately measure this value, we prepared a new type of carbonized polymer dots (CPDs) based on a solvothermal method of N,N-diethyl-p-phenylenediamine. This CPD exhibits significant fluorescence enhancement (600×) in various surfactant-contained solutions relative to its aqueous solution due to the charge transfer (CT) effect. It also shows a fluorescence change performance in different concentrations of surfactants, allowing a fluorescence measurement for CMC. Its responsive mechanism was discussed by the fluorescence lifetime and quantum yield results. Compared to the previously reported CMC probes, our developed CPD-based probe has merits in simple preparation, low cost, high availability, and easy use. This study utilized the CT feature of carbon material and widened the applications of CPDs for practical detection purposes.