Release Performance and Structural Integrity of Self-Assembled Monolayer Coatings for Anti-Adhesion Applications

Abstract

Chrome (CrOx) surfaces are widely used in industrial applications that involve interactions with polymeric materials. However, their inherently strong adhesion to polymers deposited or cast onto them can hinder clean and efficient separation. This study investigates the use of self-assembled monolayers (SAMs) on CrOx surfaces to reduce surface energy and improve the release of polymer films from chromium-coated substrates. Three SAM coatings, octylphosphonic acid (OPA), octadecylphosphonic acid (ODPA), and octadecyltrichlorosilane (OTS), were evaluated. Surface characterization of the coatings was performed using Sum Frequency Generation (SFG) Vibrational Spectroscopy. Separation behavior was examined using an acrylate-based adhesive (A-tape) and a silicone-based adhesive (S-tape) under 180° peel testing as a proxy for a broad range of polymer chemistries. Static water contact angle measurements were collected to support the SFG results. All SAM coatings showed strong performance with acrylate-based adhesives, with ODPA and OTS demonstrating particularly low peel forces and minimal surface damage. In contrast, silicone-based adhesives caused pronounced changes in surface structure, including increased gauche defects and reduced surface coverage, indicating degradation of the SAM layer. SFG analysis confirmed that the coatings retained molecular order and stability during separation from acrylate materials but not from silicone materials. Overall, the results indicate that phosphonic- and silane-based SAM coatings, particularly ODPA and OTS, have strong potential as high-performing antiadhesion layers for use on chromium oxide surfaces involving acrylate-based polymer material processing.