Dopamine-Supported Metallization of Polyolefins─A Contribution to Transfer to an Eco-friendly and Efficient Technological Process

Abstract

Metallization is a common method to produce functional or decorative coatings on plastic surfaces. State-of-the-art technologies require energy-intensive process steps and the use of organic solvents or hazardous substances to achieve sufficient adhesion between the polymer and the metal layer. The present study introduces a facile bio-inspired "green" approach to improve this technology: the use of dopamine, a smallmolecule mimic of the main structural component of adhesive mussel proteins, as an adhesion promoter. To understand dopamine adhesion and identify conditions for successful metallization, polyethylene surfaces were dip-coated with dopamine and metallized with nickel by electroless metallization; essential parameters such as temperature, pH value, concentration of dopamine and buffer, and the deposition time were systematically varied. Effects of adding oxidants to the dopamine bath, cross-linking, thermal and UV post-treatment of the polydopamine film, and plasma pretreatment of the substrate were investigated. The properties of the polydopamine layer and the quality of the metal film were studied by physico-chemical, optical, and mechanical techniques. It was shown that simple dip-coating of the substrate with dopamine under optimal conditions is sufficient to support metal layers with a good optical quality. Technologically relevant metal layer quality and adhesion were obtained with annealed and UV-treated polydopamine films and enhanced by plasma pretreatment of the substrate. The study shows that dopamine provides a new interfacial design for plastic metallization that can reduce energy consumption, use of hazardous substances, and reject rate during manufacturing. The results are essential findings for further technological developments of a universal platform to promote adhesion between plastics and metal or potentially also other material classes, enabling economic material development and more eco-friendly applications.

Improve the thermal properties of oil‐loaded polysulfone microcapsules by optimizing copper layer for self‐lubricating polyamide

“…The polymerization time had a certain effect on the adhesion properties of the final prepared copper layer on the surface of microcapsules. 44,45 Under the optimal sensitization conditions discussed above, the SEM morphologies of the PAO@PSF/ Cu microcapsules prepared by changing the polymerization time of dopamine (1, 2, 5, 10, 18 h) were shown in the Figure 3. When the polymerization time was 1 h, part of the copper layer formed on the surface of the PSF microcapsules fallen off from the microcapsule as shown in Figure 3A,A 1 , indicating that there was no good adsorption between the copper layer and the PSF shell of the microcapsule.…”

A Comprehensive Outlook of Scope within Exterior Automotive Plastic Substrates and Its Coatings

“…Among the radical changes in the metallization of plastic substrates, the bioinspired green approach by using dopamine (DA) from mussel proteins as an adhesion promoter is a typical example [96]. Earlier, it was reported to be used in membranes and biomedical applications, but herein, these UV-curable DA systems were plasma treated initially.…”

N-Type Coating of Single-Walled Carbon Nanotubes by Polydopamine-Mediated Nickel Metallization

“…New paths open up with bioinspired concepts in material science. A versatile adhesion promotion concept from the field of synthetic biology has been successfully transferred to the technical sphere in recent years, adapting the mussel adhesive derivative dopamine (DA) as an environmentally friendly bridge between different types of materials [26][27][28]. DA can be applied in a "green" process as a water-based coating.…”

“…The universal adhesion mechanism is explained by the various functional groups of DA and the fact that loosely adhering layers are replaced by DA during its polymerization directly on the surface. This reaction is accompanied by a volume contraction, which leads to interlocking with the surface [28]. In particular, the size of the CNTs and their rod shape geometrically favour stable functionalization with PDA as a closed wrapping.…”