Augustine

1. Halogenated Solvent Pre-Treatment of PMMA Substrates Significantly Improve Noble Metal Thin Film AdhesionBrian H. Augustine, James Madison University, DMR 1005641 We have discovered that exposing the surface of PMMA with either spun-cast or vapor-exposed halogenated solvents can change the adhesion of magnetron sputtered or e-beam evaporated Au thin films from nearly 0% to over 90% Au thin film adhesion. We have also demonstrated Pt adhesion by changing the solvent with a lower bond energy. • Non-complexing solvents with a high Gutmann acceptor number such as chloroform and dichloromethane improve adhesion on PMMA substrates over a factor of 4. • ATR-FTIR, XPS and EGA-FTIR evidence shows that there is a residual monolayer of CHCl3 and CH2Cl2 which remains after several days. A Lewis acid-base adduct with a binding energy of ~35 kJ/mol is formed with the ester groups in PMMA which does not happen in complexing solvents such as THF, hexanes, etc. • DFT calculations show that the solvent molecule is able to interact with the metal atoms to form an O—M—Cl bond at the surface. • JVST A paper selected by JVST editors as a featured article and sent to all AVS members in July 2011 newsletter. • Provisional patent application filed July 2011 including undergraduate co-inventor. FIGURE 2: Percent Au remaining after tape test. Red squares: tape-test performed immediately after deposition, Blue diamonds: performed after 96 hrs. in 10-6 Torr vacuum, green line O2 plasma control, red/blue dotted lines isopropyl alcohol cleaned immediate and after vacuum. FIGURE 1: Au dot array remaining on PMMA surface before tape test, after tape test and after 96 hrs. storage in 10-6 Torr vacuum. FIGURE 3: DFT modeling of model PMMA surface. (a.) Lewis acid-base adduct formed between chloroform and ester O (red atom) (b.) Cr insertion (blue atom) into bond (c.) decomposition of chloroform (d.) O—Cr—Cl bond remaining on PMMA surface.

2. Halogenated Solvent Pre-Treatment of PMMA Substrates Significantly Improve Noble Metal Thin Film Adhesion Brian H. Augustine, James Madison University, DMR 1005641 • Three undergraduate students were directly funded through this project this past summer. Two of these students are undergraduate chemistry majors and one is an undergraduate engineering major at JMU. For the summer 2011 term, one was a May 2011 graduate, Alan Mo (chemistry), one a rising junior, Skylar White (chemistry), and one was a rising senior, Stefan Jobe (engineering).Mo and Jobe worked on the Au adhesion project, and White worked on AFM studies of the phase kinetics of POSS-MA thin films. • In addition Luray High School (Va) chemistry and physics teacher, Mr. Kevin Carini, was working on fabricating polymer microfluidic structures which could be used in the teaching of Virginia Standards of Learning topics in high school chemistry and physics classes at Luray HS. He also worked with integrating NSF-funded Materials World Modules on nanoscience for his classroom. Alan Mo depositing Au thin films using e-beam evaporation in the JMU cleanroom to determine the Au adhesion onto PMMA substrates after chloroform vapor exposure. Kevin Carini (left) demonstrating a three layer PDMS microfluidic device to Prof. Chris Hughes (right). Device was designed by Carini and rapidly prototyped using CO2 laser cutter and O2 plasma bonding.