A Photolithographic Approach to Spatially Resolved Cross-Linked Nanolayers
Fuchise, K. / Lindemann, P. / Heißler, S. / Gliemann, H. / Trouillet, V. / Welle, A. / Berson, J. / Walheim, S. / Schimmel, T. / Meier, M. / Barner-Kowollik, C. (2015)
Langmuir 31 (2015), 10, 3242–3253
- Date: 2015
Fuchise, K. / Lindemann, P. / Heißler, S. / Gliemann, H. / Trouillet, V. / Welle, A. / Berson, J. / Walheim, S. / Schimmel, T. / Meier, M. / Barner-Kowollik, C. (2015): „A Photolithographic Approach to Spatially Resolved Cross-Linked Nanolayers“. In: Langmuir 31 (2015), 10, 3242–3253
The preparation of cross-linked nanosheets with 1–2 nm thickness and predefined shape was achieved by lithographic immobilization of trimethacryloyl thioalkanoates onto the surface of Si wafers, which were functionalized with 2-(phenacylthio)acetamido groups via a photoinduced reaction.
Subsequent cross-linking via free radical polymerization as well as a phototriggered Diels–Alder reaction under mild conditions on the surface led to the desired nanosheets. Electrospray ionization mass spectrometry (ESI-MS), X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), as well as infrared reflection-absorption spectroscopy (IRRAS) confirmed the success of individual surface-modification and cross-linking reactions.
The thickness and lateral size of the cross-linked structures were determined by atomic force microscopy (AFM) for samples prepared on Si wafers functionalized with a self-assembled monolayer of 1H,1H,2H,2H-perfluorodecyl groups bearing circular pores obtained via a polymer blend lithographic approach, which led to the cross-linking reactions occurring in circular nanoareas (diameter of 50–640 nm) yielding an average thickness of 1.2 nm (radical cross-linking), 1.8 nm (radical cross-linking in the presence of 2,2,2-trifluoroethyl methacrylate as a comonomer), and 1.1 nm (photochemical cross-linking) of the nanosheets.