Scalable polydopamine coatings with increased thickness and stability using polyamidoamine dendrimers

Polydopamine coatings have garnered significant attention due to their versatility and multifunctional properties, rendering them suitable for a wide array of applications, including medical devices and the creation of coatings with varying degrees of amphiphilicity. Nevertheless, the fabricating of durable polydopamine coatings with substantial thickness remains challenging, primarily due to difficulties in controlling the deposition process and the potential for coating delamination or detachment under mechanical stress. Here, we reported the development of easily scalable polydopamine (PDA) coatings with remarkable thickness (approximately 1.7 μm) and stability, adaptable to diverse materials, by incorporating an amine-containing dendrimer. Through a systematic screening process, we identified an optimal dopamine-dendrimer combination that effectively modified the synthesis of polycatecholamine, facilitated nanoparticle formation, and enhanced stability. This resulted in the controlled deposition of composite PDA nanoparticles formed in situ. Using this optimal binary composition, we achieved the eco-friendly creation of a superhydrophobic coating with exceptional stability via a one-step dip post-modification process involving polydimethylsiloxane (PDMS). This innovative approach yielded a remarkable water contact angle exceeding 150°. Furthermore, we measured advancing and receding contact angles of 155.88° and 150.90°, respectively, resulting in a hysteresis of only 4.98°.