Two-component electrochemical coupling reaction for end-group assisted electrodeposition of ultrathin polymer films
Embargo Date
2025-08-29
OA Version
Citation
Abstract
Advances in functional coatings and methods to deposit them are critical in enhancing the functionality and performance of 3D micro-architected devices in applications encompassing energy storage, electronics, as well as selective and high-capacity molecular adsorption. Electrodeposition as a non-line-of-sight fabrication method for thin films is readily adapted to modify micro 3D substrates with functional coatings. However, most polymer electrodeposition so far has been achieved by electrochemically initiated chain-growth polymerization which causes uncontrolled polymer formation when applied on 3D micro-architected substrate. Here, this project developed the electrodeposition of polymer thin films utilizing electrocoupling reaction between bromoisobutyrate (bib) and acrylate functionalities to form a step-growth polymer network. The influence of molecular concentration, solvents, and end-group ratio are investigated on planar gold electrodes, enabling tailorable control over the film thickness, molecular permeability, and chemical composition. The optimized method is applied to coat a layer with solid polymer electrolyte on a low-tortuosity 3D Carbon electrode with high aspect ratio pores of micron-scale diameters. As a result, the entire pore surface of the 3D carbon electrode is effectively enveloped by a sub-micron polymer film. The deposited polymer film exhibits high electronic resistance and can serve as a solid polymer electrolyte. This approach decouples the polymer functionality from its electrodeposition chemistry while preventing uncontrolled polymer formation away from the surface and can therefore be a universal method to coat various conductive micro-architected 3D substrates with tailorable functional polymers.