2025 AIChE Annual Meeting

Fabrication of Responsive Polymer Thin Films Via Spin-Coated Surface-Initiated Ring-Opening Metathesis Polymerization

Responsive polymer thin films with dynamic interfacial properties are essential for applications ranging from sensing, separations, and adaptive coatings.1,2 Polymer systems bearing amphiphilic functionalities are particularly valuable, as they can adapt reversibly across chemically diverse environments. This adaptation arises from the ability of the films to reorganize their interfacial composition by selectively exposing either polar or nonpolar functional groups depending on the polarity of the surrounding medium.3 While controlled radical polymerization methods such as ATRP and RAFT polymerization have been widely employed for fabricating such films, these are often slow, costly, and require stringent reaction conditions.4 In contrast, ring-opening metathesis polymerization (ROMP) provides an underexplored route with distinct advantages, including rapid kinetics, high conversion, and low polydispersity index.5,6

In this work, we present the fabrication of responsive thin films using a unique combination of spin-coating and surface-initiated ROMP (siROMP) of norbornene diacyl chloride (NBDAC) and related precursors. Post-polymerization functionalization with alcohol- and amine-terminated molecules introduces amphiphilic moieties, as confirmed by FTIR measurements. Characterization with profilometry shows controllable thickness through adjustments in spin speed, while contact-angle measurements confirm solvent-switchable wettability, consistent with surface rearrangement of functional groups.3 These results establish siROMP as a versatile platform for engineering responsive polymer coatings. Overall, this spin-coated siROMP strategy demonstrates a tunable processing route for thin films capable of dynamic adaptation to environmental cues, enabling the design of multifunctional surface technologies.

(1) Luo, Z. et al. An intelligent solvent-responsive surface molecularly imprinted membrane with switchable adsorption/desorption performance for selective separation of psoralen and recognition mechanism. Ind. Crops Prod. 207, 117766- (2024).

(2) Trivedi, J. S., Bera, P., Bhalani, D. V. & Jewrajka, S. K. In situ amphiphilic modification of thin film composite membrane for application in aqueous and organic solvents. J. Membr. Sci. 626, 119155- (2021).

(3) Uhlmann, P. et al. Surface functionalization by smart coatings: Stimuli-responsive binary polymer brushes. Prog. Org. Coat. 55, 168–174 (2006).

(4) Lunn, D. J., Discekici, E. H., Read de Alaniz, J., Gutekunst, W. R. & Hawker, C. J. Established and emerging strategies for polymer chain-end modification. J. Polym. Sci. Part Polym. Chem. 55, 2903–2914 (2017).

(5) Bielawski, C. W. & Grubbs, R. H. Living ring-opening metathesis polymerization. Prog. Polym. Sci. 32, 1–29 (2007).

(6) Choi, T.-L. & Grubbs, R. H. Controlled Living Ring‐Opening‐Metathesis Polymerization by a Fast‐Initiating Ruthenium Catalyst. doi:10.1002/anie.200250632.