Surface Science Studies of Temperature Stable Templates

NSF Grant Number: EEC-0425826
PI(s): C. Barry, J. Whitten
Student and Post-doctoral Researchers: M. Atre, S. Sengupta
Institutions: University of Massachusetts Lowell

Objective: The goals of this research are to investigate the thermal stability and performance of functionalized surfaces used by CHN as templates.

Broader Impact: For high rate polymer manufacturing processes, such as injection molding or extrusion, functionalized templates would be exposed to a hot polymer melt. For assembly and transfer with polymeric materials, it is critical that the template functionalization be able to withstand high temperatures, at least briefly, for a large number of cycles. The template based nanomanufacturing process has application for a wide range of applications including flexible electronics, structural materials, sensors, and EMI shielding.

Significant Results: This study was performed by injection molding polymethylmethacrylate (PMMA) against gold-coated silicon wafers with self-assembled monolayers (SAMS) of 1H,1H,2H,2H-perflorodecanthiol.(PFDT) and studying the durability of the SAMs by contact angle measurements and X-ray photoelectron spectroscopy. Results indicate that 1H,1H,2H,2H-perfluorodecanethiol (PFDT) self assembled monolayers (SAMs) on gold-coated silicon desorbed in the expected non-linear manner, but were sufficiently intact after 50, 100, or even 500 cycles of injection molding with PMMA at melt temperatures of 238ºC. These findings were supported by the performance of the tooling inserts during molding – i.e., the perfluorodecanethiol SAM acted as an anti-stiction coating on the tooling, facilitating ejection of the PMMA parts.

XPS normalized data for F1s signal as a function of number of injection molding cycles.