Electrodeposition of Polymer Networks as Conformal and Uniform Ultrathin Coatings

Natural systems, synthetic materials, and devices almost always feature interphases that control the flow of mass and energy or stabilize interfaces between incompatible materials. With technologies transitioning to non‐planar and 3D mesoscale architectures, novel deposition methods for realizing ultrathin coatings and interphases are required. Polymer networks are of particular interest for their tunable chemical and physical properties combined with their structural integrity. Here, the electrodeposition of polymer networks (EPoN) is introduced as a general approach to uniformly coat non‐planar conductive materials. Conceptually, EPoN utilizes electrochemically activated crosslinkers as polymer end groups to confine their network formation exclusively to the material surface upon charge transfer, yielding a passivating and self‐limiting growth of conformal and uniform coatings with tunable submicron thickness on conductive materials. EPoN is found to result in thin functional films of various polymer backbones and side group chemistries as demonstrated for poly(ether) and poly(acrylamide) based polymers as solid electrolyte and thermally responsive interphases, respectively. The fabrication of ultrathin functional coatings that are homogeneous over large areas is already difficult on planar surfaces and even tougher within porous 3D materials. Here, a universal method is reported for obtaining functional polymer networks as uniform ultrathin films on conductive surfaces of any shape by utilizing electrochemically mediated crosslinking of end‐group functionalized polymers.