Fluorescent Polyethylene by In Situ Facile Synthesis of Carbon Quantum Dots Facilitated by Silica Nanoparticle Agglomerates

We describe an in situ facile synthetic approach to prepare carbon quantum dot (CQD) fluorescent markers (FMs) for polyethylene (PE) the presence of agglomerated silica nanoparticles (SiO2 NPs) under mild reaction conditions. First SiO2 NPs, prepared by Stöber method, were dispersed toluene. This dispersion was added a PE solution After heating (either air or Ar) mixture obtained. drying, films obtained compression molding, which showed strong blue fluorescence, attributed CQDs. NPs loading values varied between 0.5 and 4 wt %. Subsequent isolation, CQDs characterized TEM, UV–vis, fluorescence spectroscopy. TEM imaging unveiled lattice spacing value 0.21 nm isolated particles is typical (100) graphite plane UV spectroscopy measurements show characteristic absorption excitation spectra aromatic core oxidized surface defects typically observed The emission maximum PE/CQD samples increased from 394 408 when temperature decreased 110 90 °C, increasing oxygen content upon decreasing temperature. When performed Ar, emitted ultraviolet region (286 nm). Finally, we demonstrated that marked with can be easily visually identified irradiating 367 light. Thus, used, example, as labeling ingredient master batches component identification recycling.