| AVS 66th International Symposium & Exhibition | |
| Applied Surface Science Division | Thursday Sessions |
| Session AS-ThP |
| Session: | Applied Surface Science Poster Session |
| Presenter: | Paul Vlasak, The Dow Chemical Company |
| Authors: | P.R. Vlasak, The Dow Chemical Company M.L. Pacholski, The Dow Chemical Company |
| Correspondent: | Click to Email |
The unique properties of poly(dimethylsiloxane), also known as PDMS or silicone, have allowed PDMS-based materials to proliferate in modern industry. A huge variety of applications using PDMS have been developed including structural adhesives, release agents, optical components, lubricants, anti-foam agents, and potting agents to name a few. Considering the omnipresence of PDMS in industrial settings along with its low surface energy and tendency to migrate, it comes as no surprise that PDMS is frequently encountered in industrial surface analysis laboratories. Because PDMS is readily detected and easily recognized by its characteristic fragmentation pattern, SIMS is well suited to identifying the presence of silicones on a wide range of materials.
Over the years we have observed variation in the fragmentation patterns and relative intensities of characteristic ions in the SIMS spectra from assorted PDMS-containing materials, however, the structural details that may influence the observed spectra remain poorly understood. In the past, we confirmed that endgroup type and molecular weight of PDMS fluids have a systematic influence on negative ion spectra. In addition, we determined that substrate type and thickness of the PDMS layer also greatly influence the spectra obtained, allowing us to hypothesize that the differing energy distributions and collisional cascades within the films and substrates strongly influence ion yields [1].
Using well-characterized PDMS reference materials spin-coated on a variety of substrates, the effects of cluster ion versus monoatomic ion sputtering will be presented as an extension of our past work. In addition, we previously demonstrated that spectra from a particular PDMS fluid became independent of substrate type as film thickness increased beyond the penetration depth of the primary ions, while current work further explores the sub-monolayer regime. Lastly, using thin films of various PDMS mixtures, investigation of potential layering of PDMS as a function of molecular weight or endgroup type will be presented.
[1] Vlasak, P.R.; Pacholski, M.L. (2018, October) Differentiating Silicones Using SIMS; presented at AVS 65th International Symposium & Exhibition, Long Beach, CA.