Fluorescent patterning of paper through laser engraving

Author(s)

Clark, Kaylee M. ^[1] ; Skrajewski, Lauren ^[1] ; Benavidez, Tomas E. ^{[1, 2]} ; Mendes, Leticia F. ^[3] ; Bastos, Erick L. ^[3] ; Dorr, Felipe A. ^[4] ; Sachdeva, Rakesh ^[1] ; Ogale, Amod A. ^{[5, 6]} ; Paixao, Thiago R. L. C. ^[3] ; Garcia, Carlos D. ^[1]

Affiliation

^[1] Clemson Univ, Dept Chem, 211 S Palmetto Blvd, Clemson, SC 29634 - USA

^[2] Natl Univ Cordoba, Sch Chem, Dept Phys Chem, INFIQC CONICET, X5000HUA, Cordoba - Argentina

^[3] Univ Sao Paulo, Dept Fundamental Chem, Inst Chem, BR-05508000 Sao Paulo, SP - Brazil

^[4] Univ Sao Paulo, Fac Pharmaceut Sci, Dept Clin & Toxicol Anal, BR-05508000 Sao Paulo, SP - Brazil

^[5] Clemson Univ, Chem Engn, Clemson, SC 29634 - USA

^[6] Clemson Univ, Ctr Adv Engn Fibers & Films, Clemson, SC 29634 - USA

• Document type: Journal article
• Source: SOFT MATTER; v. 16, n. 33, p. 7659-7666, SEP 7 2020.
• Web of Science Citations: 1

Abstract

While thermal treatment of paper can lead to the formation of aromatic structures via hydrothermal treatment (low temperature) or pyrolysis (high temperature), neither of these approaches allow patterning the substrates. Somewhere in between these two extremes, a handful of research groups have used CO2 lasers to pattern paper and induce carbonization. However, none of the previously reported papers have focused on the possibility to form fluorescent derivatives via laser-thermal engraving. Exploring this possibility, this article describes the possibility of using a CO2 laser engraver to selectively treat paper, resulting in the formation of fluorescent compounds, similar to those present on the surface of carbon dots. To determine the most relevant variables controlling this process, 3 MM chromatography paper was treated using a standard 30 W CO2 laser engraver. Under selected experimental conditions, a blue fluorescent pattern was observed when the substrate was irradiated with UV light (365 nm). The effect of various experimental conditions (engraving speed, engraving power, and number of engraving steps) was investigated to maximize the fluorescence intensity. Through a comprehensive characterization effort, it was determined that 5-(hydroxymethyl)furfural and a handful of related compounds were formed (varying in amount) under all selected experimental conditions. To illustrate the potential advantages of this strategy, that could complement those applications traditionally developed from carbon dots (sensors, currency marking, etc.), a redox-based optical sensor for sodium hypochlorite was developed. (AU)

• FAPESP's process: 18/16250-0 - Development of portable electrochemical devices on polymer materials using CO2 laser for analytical applications
• Grantee: Letícia Francine Mendes
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/08782-1 - Miniaturized and integrated chemical sensors: new fabrication platforms for biological, clinical and environmental applications
• Grantee: Mauro Bertotti
• Support Opportunities: Research Projects - Thematic Grants