Professor Stephen A. Morin
Date of this Version
Kapitan, John Michael, "Surface Functionalization of Elastomers for Tunable Crystal Growth and Smart Adhesives" (2021).
Silicone rubbers have seen extensive work on modulation of their surface environments for use in microfluidics, cell adhesion, and sensing. Most surface procedures utilize a common initial step of oxidation of the surface to increase the number of active surface functional groups. Following oxidation more permanent functionalities can be imparted on the surface using silanization, grafting polymer brushes, or creating ionic bonds to the surface. Of these three, silanization proves to be the most pervasive due to the range of procedures available and how easy the procedures prove to be. However, the mechanism by which silanization is performed heavily involves reactivity with alcohol groups making the procedure unavailable to functional groups containing alcohols and functional groups that share similar structural features. Expanding the scope of functional groups available through silanization can be achieved by attaching groups to the surface that can be easily replaced or transformed. Increasing the scope of available surface functional groups was achieved by using the copper catalyzed azide-alkyne click reaction.
Controlling the areas that reactivity occurs at, by using patterning techniques, allow for the generation of distinct regimes of surface chemistry. This can allow for wholly new surface functions such as the ordering of large arrays of liquid droplets, directional control of the movement of droplets across the surface, and control over the adhesive forces the surface experiences. Combining chemical patterning with physical patterning, selective removal of contact areas, allowed for fine tuning of the adhesive properties and produced a favorable delamination axis. The work outlined here is applicable to a broad range of fields including, biomineralization, biomaterial engineering, and adhesive design.
Advisor: Stephen A. Morin