Self-Assembled Melamine Monolayer on Cu(111)

• Published in: Journal of physical chemistry. C Vol. 117; no. 19; pp. 9895 - 9902
• Main Authors: Lin, Yu-Pu, Ourdjini, Oualid, Giovanelli, Luca, Clair, Sylvain, Faury, Thomas, Ksari, Younal, Themlin, Jean-Marc, Porte, Louis, Abel, Mathieu
• Format: Journal Article
• Language: English
• Published: Columbus, OH American Chemical Society 16.05.2013
• Subjects: Chemical Sciences; Condensed Matter; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Material chemistry; Materials Science; Methods of nanofabrication; Physics; Self-assembly; Temperature dependence; X-ray microscopy; Polymerization; Annealing temperature; Triamine; Self-assembled layers; High vacuum; Scanning tunneling microscopy; Self-assembly; Self organization; Monolayers; Ultraviolet photoelectron spectra; Thermal annealing; Conformation; X-ray photoelectron spectra
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp401496s

The self-assembled structure of melamine (1,3,5-triazine-2,4,6-triamine) deposited on Cu(111) was studied under ultra-high-vacuum conditions using scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and ultraviolet photoemission spectroscopy (UPS). Molecular packing and conformation were investigated as a function of the annealing temperature. The molecules deposited at room temperature were found to be aligned with the molecular plane approximately perpendicular to the surface. At around 150 °C, the molecules became aligned in a row-type structure and were all coupled to the Cu(111) surface. At still higher annealing temperatures, a new two-dimensional (2D) network was formed via the polymerization of the adsorbed monolayer of melamine. A multistep model consistent with STM, XPS, and UPS results is proposed, starting with a self-organized vertically adsorbed melamine monolayer and ending with the formation of a 2D network lying on Cu(111) interpreted as a ring-opening polymerization of melamine. The reactive Cu(111) surface is believed to be one of the keys in this multistep reaction.