Self-Limiting Electrospray Deposition of Polymers and Polymer Composites

Electrospray deposition is widely used to create polymer microcoatings from dilute spray solutions. In a certain regime of experimental parameters, a limiting thickness emerges where the accumulation of charge repels further spray. This self-limiting electrospray deposition (SLED) can uniformly cover complex multiscale structures efficiently. Here we investigate the application of polymer blends to increasing the durability of the spray films for different mechanical applications. We use the addition of photo- or thermal-crosslinkers that can either maintain the hierarchical spray structure of hollow particles or result in a dense film to obtain stiffer coatings for protective barriers. The results show mechanically-tough coatings with tunable porosity which are resistant to decomposition by chemical reactions and mechanical damage. To make the films that are more flexible for compliant surfaces, polymer blends which consisting of plastic and elastomeric components are sprayed. The net result was a coating that could enhance adhesion and sustain ~17% strain in the underlying structure. Furthermore, we have applied SLED to coat 3D structures produced via additive manufacturing with these mechanically-tuned coatings.