TY - JOUR
T1 - Fluorescent Polyethylene by in Situ Facile Synthesis of Carbon Quantum Dots Facilitated by Silica Nanoparticle Agglomerates
AU - Yin, Sida
AU - Duvigneau, Joost
AU - Vancso, G. Julius
N1 - Funding Information:
This work was funded as part of the Interreg V project Druckbare RFID-Tags für Massenmärkte (DruIDe) and by the University of Twente. The authors thank Dr. Hubert Gojzewski for the help with conducting AFM measurements. The authors also acknowledge M.S.c. Min Lin for her help with UV–vis microscopy measurements.
Publisher Copyright:
©
PY - 2021/11/12
Y1 - 2021/11/12
N2 - We describe an in situ facile synthetic approach to prepare carbon quantum dot (CQD) fluorescent markers (FMs) for polyethylene (PE) in the presence of agglomerated silica nanoparticles (SiO2 NPs) under mild reaction conditions. First SiO2 NPs, prepared by the Stöber method, were dispersed in toluene. This dispersion was added to a PE solution in toluene. After heating (either in air or under Ar) a fluorescent mixture was obtained. After drying, PE films were obtained by compression molding, which showed strong blue fluorescence, attributed to CQDs. SiO2 NPs loading values varied between 0.5 and 4 wt %. Subsequent to isolation, the fluorescent CQDs were characterized by TEM, UV-vis, and fluorescence spectroscopy. TEM imaging unveiled a lattice spacing value of 0.21 nm of the isolated fluorescent particles which is typical for (100) graphite plane lattice spacing in CQDs. UV spectroscopy and fluorescence measurements show characteristic absorption and excitation spectra for the aromatic core and oxidized surface defects typically observed for CQDs. The emission maximum for PE/CQD samples increased from 394 to 408 nm when the reaction temperature was decreased from 110 to 90 °C, which is attributed to increasing oxygen content in the reaction mixture upon decreasing the reaction temperature. When the reaction was performed under Ar, the PE/CQD samples emitted in the ultraviolet region (286 nm). Finally, we demonstrated that PE samples marked with CQDs can be easily visually identified upon irradiating with 367 nm light. Thus, the marked PE can be used, for example, as a labeling ingredient in master batches for component identification and in recycling.
AB - We describe an in situ facile synthetic approach to prepare carbon quantum dot (CQD) fluorescent markers (FMs) for polyethylene (PE) in the presence of agglomerated silica nanoparticles (SiO2 NPs) under mild reaction conditions. First SiO2 NPs, prepared by the Stöber method, were dispersed in toluene. This dispersion was added to a PE solution in toluene. After heating (either in air or under Ar) a fluorescent mixture was obtained. After drying, PE films were obtained by compression molding, which showed strong blue fluorescence, attributed to CQDs. SiO2 NPs loading values varied between 0.5 and 4 wt %. Subsequent to isolation, the fluorescent CQDs were characterized by TEM, UV-vis, and fluorescence spectroscopy. TEM imaging unveiled a lattice spacing value of 0.21 nm of the isolated fluorescent particles which is typical for (100) graphite plane lattice spacing in CQDs. UV spectroscopy and fluorescence measurements show characteristic absorption and excitation spectra for the aromatic core and oxidized surface defects typically observed for CQDs. The emission maximum for PE/CQD samples increased from 394 to 408 nm when the reaction temperature was decreased from 110 to 90 °C, which is attributed to increasing oxygen content in the reaction mixture upon decreasing the reaction temperature. When the reaction was performed under Ar, the PE/CQD samples emitted in the ultraviolet region (286 nm). Finally, we demonstrated that PE samples marked with CQDs can be easily visually identified upon irradiating with 367 nm light. Thus, the marked PE can be used, for example, as a labeling ingredient in master batches for component identification and in recycling.
KW - Carbon quantum dots
KW - Fluorescence
KW - Optical markers
KW - Plastic sorting
KW - Polyethylene (PE)
KW - Silica nanoparticles
KW - UT-Hybrid-D
UR - http://www.scopus.com/inward/record.url?scp=85118620944&partnerID=8YFLogxK
U2 - 10.1021/acsapm.1c00821
DO - 10.1021/acsapm.1c00821
M3 - Article
AN - SCOPUS:85118620944
VL - 3
SP - 5517
EP - 5526
JO - ACS Applied Polymer Materials
JF - ACS Applied Polymer Materials
SN - 2637-6105
IS - 11
ER -