Abstract :
I investigated the effect of strain on the deposition of carboxylic acid-terminated thiol and peptides on polyvinylmethylsiloxane (PVMS) network surfaces. Additionally, the material properties of PVMS networks were assessed. The goal of my project is to use strain to obtain a PVMS network with a higher surface density of peptides attached per area than prior processes. Initial experiments investigated different formulations of PVMS networks (ratio of polymer to crosslinker) to determine a candidate that would have a significant ultimate strain while still being easy to handle without breaking. Once selected, PVMS network samples underwent thiol deposition side by side, one strained the other unstrained. Fourier transform infrared spectroscopy operated in Attenuated total reflection mode. (FTIR-ATR) was used to assess the surface composition. Initial results were varied; so the samples were washed overnight in methanol to remove any unattached thiol and tested again. Thiol peaks decreased greatly, especially in the strained samples. To remedy this issue, the samples were extracted before undergoing deposition. Preliminary results suggest that it makes little difference. Our findings so far suggest that straining may be detrimental to thiol deposition on PVMS. We hypothesize that strain keeps the PVMS network from properly aligning with the thiol molecules for the reaction to occur. Ongoing work is addressing this issue further and is investigating the use of lower strains and higher thiol concentrations.
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